저자 밴 더 빌 트 대학 재정 지원에 대 한 화학 생물학 연구소를 인정 하 고 싶습니다. 미스터 버클리 엘리스와 교수 존 맥 클린 High-Resolution 질량 스펙트럼 분석에 대 한 인정 됩니다.

1. 대표 전자 레인지-Denitration 지원
<ol><li>Azido 질 산 에스테 르를 배치 (1.0 equiv., 0.2 m m o l) 8 mL 전자 레인지 반응 유리병에서. 반응의 규모는 반응 진행에 어떤 악영향 없이 여러 mmol을 늘릴 수 있습니다.</li>
	<li>Azido-질 산 에스테 르 20 %aq. 아세톤 (0.1 M 2.0 mL)에 녹. 반응 배를 피리 딘 (5.0 equiv., 0.08 mL, 1.0 mmol)을 추가 합니다. 전자 레인지 방사선 유리병 뚜껑과 전자 레인지 원자로 캐비티에 반응 배를 놓습니다.</li>
	<li>교 반 및 고정된 유지 시간 15 분 동안 120 ° C에서 솔루션 비추는 보류 시간 얼마나 방사선 지정 된 온도 및 결과 압력 발생 합니다 나타냅니다. 램프 2 분 동안 모든 반응 보고 온도에 열. 내장 IR 센서가 온도 모니터링 합니다.</li>
	<li>15 분 후 얇은 층 크로마토그래피 (TLC)를 사용 하 여 시작 물자의 소비를 확인 하는 반응 혼합물을 분석 합니다. Eluent는으로 1:1 에틸 아세테이트/hexanes를 사용 합니다.<ol>
<li>TLC 판 ceric 암모늄 molybate 얼룩을 사용 하 여 시각화. 반응 물 및 제품의 Rf 달라 집니다 하지만 줄이는 알코올 반응 보다 일반적으로 0.05에서 0.1 낮은 Rf .</li>
	</ol>
</li>
</ol>2입니다.는 trichloroacetimidate의 형성
<ol><li>시작 물자의 완전 한 소비에 따라 항공사를 사용 하 여 감소 볼륨에 용 매를 증발. 다음, (dichloromethane) 채널2Cl2 (1.0 mL)로 희석 하 고 주사기를 사용 하 여 물 층을 제거. 물 레이어 제거 되 면 얼음 물 목욕을 사용 하 여 0 ° C에 반응 혼합물을 냉각 한다.</li>
	<li>다음, 반응 배를 DBU (10 eq, 0.3 mL, 1.9 mmol)와 2,2,2-trichloroacetonitrile (50 eq, 1.0 mL, 10 mmol)을 추가 합니다. 두 시 약 과잉에 추가 되 고 기지의 1 해당 고 1 상응 하는 2,2,2 trichloroacetonitrile의 최소 필요.</li>
	<li>주위 온도에 온난 하는 동안 저 어 반응 혼합물을 허용 한다. TLC 확인 시작 물자의 소비에 의해 반응을 모니터링 합니다.<ol>
<li>Eluent는으로 1:1 에틸 아세테이트/hexanes를 사용 합니다. TLC 판 ceric 암모늄 molybate 얼룩을 사용 하 여 시각화. 반응 물 및 제품의 Rf 달라질 수 있습니다.</li>
	</ol>
</li>
	<li>시작 물자의 완전 한 소비 후 복구 플라스 크에 반응 혼합물을 전송 하 고 혼합물 vacuo에서 30 ° c.에 집중 솔벤트의 증발 갈색 기름 원유 옅은 노란색을 제공 합니다.</li>
	<li>Eluent로 1.5 cm 크로마토그래피 열과 1:4 에틸 아세테이트/hexanes 실리 카 젤 컬럼 크로마토그래피에 의해 원유 제품을 정화. imidate의 물리적 형태는 분자에서 분자를 달라 집니다.</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56610/56610fig1v3.jpg"> 그림 1. 2-azido-1-trichloroimidates 2-azido-1-질 산 에스테 르의 한 냄비 변환의 대표적인 예. <a href="//cloudflare.jove.com/files/ftp_upload/56610/56610fig1v3large.jpg" target="_blank">이 그림의 더 큰 버전을 보려면 여기를 클릭 하십시오.</a>

<ol>
	<li>Nicolaou, K. C., Mitchell, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Adventures+in+Carbohydrate+Chemistry:+New+Synthetic+Technologies,+Chemical+Synthesis,+Molecular+Design,+and+Chemical+Biology+A+list+of+abbreviations+can+be+found+at+the+end+of+this+article.+Telemachos+Charalambous+was+an+inspiring+teacher+at+the+Pancyprian+Gymnasium,+Nicosia,+Cyprus.">Adventures in Carbohydrate Chemistry: New Synthetic Technologies, Chemical Synthesis, Molecular Design, and Chemical Biology A list of abbreviations can be found at the end of this article. Telemachos Charalambous was an inspiring teacher at the Pancyprian Gymnasium, Nicosia, Cyprus.</a> Angew. Chem. Int. Ed. Engl. 40 (9), 1576-1624 (2001).</li><li>Danishefsky, S. J., Allen, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+the+laboratory+to+the+clinic:+A+retrospective+on+fully+synthetic+carbohydrate-based+anticancer+vaccines.">From the laboratory to the clinic: A retrospective on fully synthetic carbohydrate-based anticancer vaccines.</a> Angew. Chem. Int. Ed. Engl. 39 (5), 836-863 (2000).</li><li>Nicolaou, K. C., Hale, C. R. H., Nilewski, C., Ioannidou, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constructing+molecular+complexity+and+diversity:+total+synthesis+of+natural+products+of+biological+and+medicinal+importance.">Constructing molecular complexity and diversity: total synthesis of natural products of biological and medicinal importance.</a> Chemical Society Reviews. 41 (15), 5185-5238 (2012).</li><li>Zhu, X., Schmidt, R. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+principles+for+glycoside-bond+formation.">New principles for glycoside-bond formation.</a> Angew. Chem. Int. Ed. Engl. 48 (11), 1900-1934 (2009).</li><li>Danishefsky, S. J., Bilodeau, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycals+in+organic+synthesis:+The+evolution+of+comprehensive+strategies+for+the+assembly+of+oligosaccharides+and+glycoconjugates+of+biological+consequence.">Glycals in organic synthesis: The evolution of comprehensive strategies for the assembly of oligosaccharides and glycoconjugates of biological consequence.</a> Angew. Chem. Int. Ed. Engl. 35 (13-14), 1380-1419 (1996).</li><li>Bongat, A. F., Demchenko, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+trends+in+the+synthesis+of+O-glycosides+of+2-amino-2-deoxysugars.">Recent trends in the synthesis of O-glycosides of 2-amino-2-deoxysugars.</a> Carbohydr. Res. 342 (3-4), 374-406 (2007).</li><li>Feizi, T., Fazio, F., Chai, W. C., Wong, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbohydrate+microarrays+-+a+new+set+of+technologies+at+the+frontiers+of+glycomics.">Carbohydrate microarrays - a new set of technologies at the frontiers of glycomics.</a> Curr. Opin. Struct. Biol. 13 (5), 637-645 (2003).</li><li>Palmacci, E. R., Plante, O. J., Seeberger, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oligosaccharide+synthesis+in+solution+and+on+solid+support+with+glycosyl+phosphates.">Oligosaccharide synthesis in solution and on solid support with glycosyl phosphates.</a> Eur. J. Org. Chem. (4), 595-606 (2002).</li><li>Stallforth, P., Lepenies, B., Adibekian, A., Seeberger, P. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=2009+Claude+S.+Hudson+Award+in+Carbohydrate+Chemistry.+Carbohydrates:+a+frontier+in+medicinal+chemistry.">2009 Claude S. Hudson Award in Carbohydrate Chemistry. Carbohydrates: a frontier in medicinal chemistry.</a> J. Med. Chem. 52 (18), 5561-5577 (2009).</li><li>Danishefsky, S. J., Mcclure, K. F., Randolph, J. T., Ruggeri, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Strategy+for+the+Solid-Phase+Synthesis+of+Oligosaccharides.">A Strategy for the Solid-Phase Synthesis of Oligosaccharides.</a> Science. 260 (5112), 1307-1309 (1993).</li><li>Demchenko, A. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stereoselective+chemical+1,2-cis+O-glycosylation:+From+'sugar+ray'+to+modern+techniques+of+the+21st+century.">Stereoselective chemical 1,2-cis O-glycosylation: From 'sugar ray' to modern techniques of the 21st century.</a> Synlett. (9), 1225-1240 (2003).</li><li>Fraserreid, B., Wu, Z. F., Udodong, U. E., Ottosson, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Armed-Disarmed+Effects+in+Glycosyl+Donors+-+Rationalization+and+Sidetracking.">Armed-Disarmed Effects in Glycosyl Donors - Rationalization and Sidetracking.</a> J. Org. Chem. 55 (25), 6068-6070 (1990).</li><li>Bohe, L., Crich, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+propos+of+glycosyl+cations+and+the+mechanism+of+chemical+glycosylation;+the+current+state+of+the+art.">A propos of glycosyl cations and the mechanism of chemical glycosylation; the current state of the art.</a> Carbohydr. Res. 403, 48-59 (2015).</li><li>Toshima, K., Tatsuta, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+Progress+in+O-Glycosylation+Methods+and+Its+Application+to+Natural-Products+Synthesis.">Recent Progress in O-Glycosylation Methods and Its Application to Natural-Products Synthesis.</a> Chem. Rev. 93 (4), 1503-1531 (1993).</li><li>Koenigs, W., Knorr, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ueber+einige+Derivate+des+Traubenzuckers+und+der+Galactose.">Ueber einige Derivate des Traubenzuckers und der Galactose.</a> Chem. Ber. 34 (1), 957-981 (1901).</li><li>Mukaiyama, T., Murai, Y., Shoda, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Efficient+Method+for+Glucosylation+of+Hydroxy+Compounds+Using+Glucopyranosyl+Fluoride.">An Efficient Method for Glucosylation of Hydroxy Compounds Using Glucopyranosyl Fluoride.</a> Chem. Lett. (3), 431-432 (1981).</li><li>Meloncelli, P. J., Martin, A. D., Lowary, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosyl+iodides.+History+and+recent+advances.">Glycosyl iodides. History and recent advances.</a> Carbohydrate Research. 344 (9), 1110-1122 (2009).</li><li>Lian, G., Zhang, X., Yu, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thioglycosides+in+carbohydrate+research.">Thioglycosides in carbohydrate research.</a> Carbohydr. Res. 403, 13-22 (2015).</li><li>Schmidt, R. R., Kinzy, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anomeric-Oxygen+Activation+for+Glycoside+Synthesis+-+the+Trichloroacetimidate+Method.">Anomeric-Oxygen Activation for Glycoside Synthesis - the Trichloroacetimidate Method.</a> Advances in Carbohydrate Chemistry and Biochemistry. 50, 21-123 (1994).</li><li>Schmidt, R. R., Toepfer, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glycosylation+with+highly+reactive+glycosyl+donors:+efficiency+of+the+inverse+procedure.">Glycosylation with highly reactive glycosyl donors: efficiency of the inverse procedure.</a> Tetrahedron Lett. 32 (28), 3353-3356 (1991).</li><li>Keith, D. J., Townsend, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct,+microwave-assisted+substitution+of+anomeric+nitrate-esters.">Direct, microwave-assisted substitution of anomeric nitrate-esters.</a> Carbohydr. Res. 442, 20-24 (2017).</li><li>Bukowski, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+Conformational+Analysis+of+the+T-Antigen+Disaccharide(B-D-Gal-(1->3)-a-D-GalNAc-OMe).">Synthesis and Conformational Analysis of the T-Antigen Disaccharide(B-D-Gal-(1->3)-a-D-GalNAc-OMe).</a> Eur. J. Org. Chem. 14, 2697-2705 (2001).</li></ol>

저자 아무 경쟁 금융 관심사 있다.

이 자습서에 설명 된 프로토콜 질 산 에스테 르 반응, 유용한 기능을 변환 하는 메서드를 제공 합니다. 넓은 의미에서 탄수화물 합성의 과정을 통해 특정 훈련을 완료 하는 데 전자 레인지 원자로 고용 수 있도록 어려운 변환 손쉬운 일상적인 가능성이 있다. 이 자습서에서 우리의 목표는 마이크로파 방사선의 맥락에서 탄수화물을 처리 하는 방법을 보여 줍니다.
부모 반응의 ?...

분자 생물학에 있는 그들의 편 재 때문에 탄수화물 화학 합성에 대 한 오랜 목표 되었습니다. 1 , 2 , 3 어떤 성공적인 합성 캠페인의 핵심 처리한후 체인 만들려고 glycosylation 반응의 정확한 배포가입니다. 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 당연한, 있다 glycosidic 채권을 설치 하는 방법의 많은 수 없습니다. 13 , 14 는 Koenigs Knorr 메서드는 가장 이른 알려진된 절차 중 하나 이며 커플링 glycosyl 염화 또는 평범한 사람 중 금속 (수은 또는 은색) 활성화의 밑에 보통 알코올 구성 요소를 포함. 15 관련된 glycosyl 불 화물 처음 소개 기증자로 1981에서 Mukaiyama 그룹 그리고 그들의 증가 한 열과 화학 안정성 때문에 광범위 하 게 응용 프로그램을 발견 했다. 16 반응 스펙트럼의 반대쪽 끝에 다른 할로겐 보다 훨씬 반응성은 glycosyl iodides 있습니다. 증가 된 반응성 증가 stereocontrol, 특히 때 α 연결 oligosaccharides 형성을 동반 된다. 17 "haloglycosides", 뿐만 아니라 thioglycosides 발견 했다 다양 한 유틸리티, 부분적으로, 형성, 다양 한 반응 조건, 및 electrophilic 시 약으로 활성화 하는 안정성의 그들의 용이성으로 인해. 18
Anomeric 알코올 "산소"를 포함 하는에 잠재적인 그룹을 활성화 하 고 궁극적으로 수락자 분자에서 알코올에 의해 난민을 떠나 변환에 초점 위에서 설명한 방법. Anomeric 산소 활성화 슈미트 학교에 의해 설명 된 대로 자체, C1 산소 떠나는 그룹으로 변환에 집중 한다. 19 이 방법은 가장 강력한 이며 화학 glycosylation 반응에서 널리 이용 된다. Trichloroacetimidate 기증자는 쉽게 감소 설탕과 탄산 칼륨 (K2CO3) 또는 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU) 등 자료의 trichloroacetonitrile에서 준비 됩니다. 이러한 종 다음 루이스 산을 사용 하 여 활성화 됩니다. 20
최근에, 우리는 2-azido-1-trichloroacetimidate 기증자 직접 glycals에서 준비 될 수 있다 보고 있다. 과정 2 반응을, 2-azido-1-질 산 에스테 르에서 한 냄비 절차를 포함 한다. 21 이 상세한 프로토콜 고수익 변환을 성공적으로 완료에 실무자를 지원 하기 위한 것입니다. 특히 전자 레인지-열 denitration에는 초점을 맞추고 보조 난방 시퀀스의 첫 번째 단계가입니다. 우리는 또한 유기 합성 반응 기 전자 레인지 사용에 영상 자습서를 제공 하도록 하겠습니다.

<table>
	<tbody>
		<tr>
			<td>230 400 mesh silica gel</td>
			<td>SiliCycle Inc</td>
			<td>R10030B</td>
			<td></td>
		</tr>
		<tr>
			<td>TLC plates</td>
			<td>SiliCycle Inc</td>
			<td>TLG-R10014B-527</td>
			<td></td>
		</tr>
		<tr>
			<td>Ceric ammonium molybdate</td>
			<td>Sigma-Aldrich</td>
			<td>A1343</td>
			<td></td>
		</tr>
		<tr>
			<td>Solvent Still</td>
			<td>Mbraun</td>
			<td>MB-SPS-800</td>
			<td></td>
		</tr>
		<tr>
			<td>Infared spectrometer</td>
			<td>Thermo</td>
			<td>Thermo Electron IR100</td>
			<td></td>
		</tr>
		<tr>
			<td>Nuclear Magnetic Resonance</td>
			<td>Bruker</td>
			<td></td>
			<td>400, 600 MHz</td>
		</tr>
		<tr>
			<td>LC/MS</td>
			<td>Thermo/Dionex</td>
			<td></td>
			<td>Single quad, ESI</td>
		</tr>
		<tr>
			<td>HRMS</td>
			<td>Agilent</td>
			<td>Synapt G2 S HDMS</td>
			<td></td>
		</tr>
		<tr>
			<td>Microwave reactor</td>
			<td>Anton Parr</td>
			<td>Anton Parr G10 Monowave 200</td>
			<td></td>
		</tr>
		<tr>
			<td>DBU</td>
			<td>Sigma-Aldrich</td>
			<td>139009</td>
			<td></td>
		</tr>
		<tr>
			<td>CCl3CN</td>
			<td>Sigma-Aldrich</td>
			<td>T53805</td>
			<td></td>
		</tr>
		<tr>
			<td>Pyridine</td>
			<td>Sigma-Aldrich</td>
			<td>270970</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Fisher Scientific</td>
			<td>A18-20</td>
			<td>Tech. grade</td>
		</tr>
		<tr>
			<td>Phase separator</td>
			<td>Biotage</td>
			<td>120-1901-A</td>
			<td></td>
		</tr>
		<tr>
			<td>Rotary evaporator</td>
			<td>Buchi</td>
			<td>R-100</td>
			<td></td>
		</tr>
	</tbody>
</table>

one-pot microwave-assisted conversion of anomeric nitrate-esters to trichloroacetimidates

다음 절차의 목표 trichloroacetimidate glycosyl 기증자에 게는 2-azido-1-질 산-에스테 르의 한 냄비 변환의 데모를 제공 하는 것입니다. glycal의 azido nitration, 다음 전자 레인지를 이용한 방사선에서 제품 2-azido-1-질 산 에스테 르를 분해 수 있습니다. 이 변환은 일반적으로 강하게 및 시 약 및 확장 된 반응 시간을 사용 하 여 이루어집니다. 마이크로파 방사선 조사는 가수분해, 짧은 반응 시간, 시 약의 부재에서 유도합니다. Denitration, 다음에 해당 2-azido-1-trichloroacetimidate를 같은 냄비에 중간 anomeric 알콜 변환 됩니다.

3 2-azido-1-질 산 에스테 르의 수영장에 여기에 설명 된 기술을 시연 했다. 각각의 경우에는 반응의 첫 번째 단계 20 분 이내에 완료 했다.
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56610/56610fig2v3.jpg"> 그림 2. 가수분해의 대표적인 예 (1 →2), 그리고 1 의 2-azido-1-질 산 에스테 ?...

Watch this Scientific Journal Video about One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates at JoVE.com

One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

한 냄비 전자 렌지를 이용한 변환 Anomeric 질 산 에스테 르의 Trichloroacetimidates

2-azido-1-질 산-에스테 르는 해당 2-azido-1-trichloroacetimidate 한 냄비 절차에서를 변환할 수 있습니다. 원고의 목표 탄수화물 합성에 전자 레인지 원자로의 유틸리티를 설명 하는 것입니다.

The goal of the following procedure is to provide a demonstration of the one-pot conversion of a 2-azido-1-nitrate-ester to a trichloroacetimidate ...

one-pot-microwave-assisted-conversion-anomeric-nitrate-esters-to

Research

JoVE Journal

Chemistry

7.4K 조회수.  Vanderbilt University. 2-azido-1-질 산-에스테 르는 해당 2-azido-1-trichloroacetimidate 한 냄비 절차에서를 변환할 수 있습니다. 원고의 목표 탄수화물 합성에 전자 레인지 원자로의 유틸리티를 설명 하는 것입니다.

비디오: One-pot Microwave-assisted Conversion of Anomeric Nitrate-esters to Trichloroacetimidates

Microwave-assisted Intramolecular Dehydrogenative Diels-Alder Reactions for the Synthesis of Functionalized Naphthalenes/Solvatochromic Dyes

Functionalized naphthalenes have applications in a variety of research fields ranging from the synthesis of natural or biologically active molecules to the preparation of new organic dyes. Although numerous strategies have been reported to access naphthalene scaffolds, many procedures still present limitations in terms of incorporating functionality, which in turn narrows the range of available substrates. The development of versatile methods for direct access to substituted naphthalenes is therefore highly desirable.
The Diels-Alder (DA) cycloaddition reaction is a powerful and attractive method for the formation of saturated and unsaturated ring systems from readily available starting materials. A new microwave-assisted intramolecular dehydrogenative DA reaction of styrenyl derivatives described herein generates a variety of functionalized cyclopenta[b]naphthalenes that could not be prepared using existing synthetic methods. When compared to conventional heating, microwave irradiation accelerates reaction rates, enhances yields, and limits the formation of undesired byproducts.
The utility of this protocol is further demonstrated by the conversion of a DA cycloadduct into a novel solvatochromic fluorescent dye via a Buchwald-Hartwig palladium-catalyzed cross-coupling reaction. Fluorescence spectroscopy, as an informative and sensitive analytical technique, plays a key role in research fields including environmental science, medicine, pharmacology, and cellular biology. Access to a variety of new organic fluorophores provided by the microwave-assisted dehydrogenative DA reaction allows for further advancement in these fields.

Microwave-assisted intramolecular dehydrogenative Diels-Alder (DA) reactions provide concise access to functionalized cyclopenta[b]naphthalene building blocks. The utility of this methodology is demonstrated by one-step conversion of the dehydrogenative DA cycloadducts into novel solvatochromic fluorescent dyes via Buchwald-Hartwig palladium-catalyzed cross-coupling reactions.

작용 Naphthalenes / Solvatochromic의 염료의 합성을위한 전자 레인지를 이용한 분자 Dehydrogenative Diels-앨더 반응

Functionalized naphthalenes have applications in a variety of research fields ranging from the synthesis of natural or biologically active molecules to ...

연구

화학

Microwave-assisted Functionalization of Poly(ethylene glycol) and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation

One of the main benefits to using poly(ethylene glycol) (PEG) macromers in hydrogel formation is synthetic versatility. The ability to draw from a large variety of PEG molecular weights and configurations (arm number, arm length, and branching pattern) affords researchers tight control over resulting hydrogel structures and properties, including Young&#8217;s modulus and mesh size. This video will illustrate a rapid, efficient, solvent-free, microwave-assisted method to methacrylate PEG precursors into poly(ethylene glycol) dimethacrylate (PEGDM). This synthetic method provides much-needed starting materials for applications in drug delivery and regenerative medicine. The demonstrated method is superior to traditional methacrylation methods as it is significantly faster and simpler, as well as more economical and environmentally friendly, using smaller amounts of reagents and solvents. We will also demonstrate an adaptation of this technique for on-resin methacrylamide functionalization of peptides. This on-resin method allows the N-terminus of peptides to be functionalized with methacrylamide groups prior to deprotection and cleavage from resin. This allows for selective addition of methacrylamide groups to the N-termini of the peptides while amino acids with reactive side groups (e.g.&#160;primary amine of lysine, primary alcohol of serine, secondary alcohols of threonine, and phenol of tyrosine) remain protected, preventing functionalization at multiple sites. This article will detail common analytical methods (proton Nuclear Magnetic Resonance spectroscopy (;H-NMR) and Matrix Assisted Laser Desorption Ionization Time of Flight mass spectrometry (MALDI-ToF)) to assess the efficiency of the functionalizations. Common pitfalls and suggested troubleshooting methods will be addressed, as will modifications of the technique which can be used to further tune macromer functionality and resulting hydrogel physical and chemical properties. Use of synthesized products for the formation of hydrogels for drug delivery and cell-material interaction studies will be demonstrated, with particular attention paid to modifying hydrogel composition to affect mesh size, controlling hydrogel stiffness and drug release.

Microwave-assisted Functionalization of Polyethylene glycol and On-resin Peptides for Use in Chain Polymerizations and Hydrogel Formation

This video will illustrate a rapid, efficient method to methacrylate poly(ethylene glycol), enabling chain polymerizations and hydrogel synthesis. It will demonstrate how to similarly introduce methacrylamide functionalities into peptides, detail common analytical methods to assess functionalization efficiency, provide suggestions for troubleshooting and advanced modifications, and demonstrate typical hydrogel characterization techniques.

전자 레인지를 이용한 폴리의 기능화 (에틸렌 글리콜) 및 체인 중합 및 하이드로 겔 형성에있는 사용을위한 온 수지 펩티드

One of the main benefits to using poly(ethylene glycol) (PEG) macromers in hydrogel formation is synthetic versatility. The ability to draw from a large ...

Preparation of Silica Nanoparticles Through Microwave-assisted Acid-catalysis

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle diameters ranging from 30-250 nm by varying the reaction conditions. Through the selection of a microwave compatible solvent, silicic acid precursor, catalyst, and microwave irradiation time, these microwave-assisted methods were capable of overcoming the previously reported shortcomings associated with synthesis of silica nanoparticles using microwave reactors. The siloxane precursor was hydrolyzed using the acid catalyst, HCl. Acetone, a low-tan &#948; solvent, mediates the condensation reactions and has minimal interaction with the electromagnetic field. Condensation reactions begin when the silicic acid precursor couples with the microwave radiation, leading to silica nanoparticle sol formation. The silica nanoparticles were characterized by dynamic light scattering data and scanning electron microscopy, which show the materials&#39; morphology and size to be dependent on the reaction conditions. Microwave-assisted reactions produce silica nanoparticles with roughened textured surfaces that are atypical for silica sols produced by St&#246;ber&#39;s methods, which have smooth surfaces.

Silica nanoparticles were prepared using acid-catalysis of a siloxane precursor and microwave-assisted synthetic techniques resulting in the controlled growth of nanomaterials ranging from 30-250 nm in diameter. The growth dynamics can be controlled by varying the initial silicic acid concentration, time of the reaction, and temperature of reaction.

전자 레인지를 이용한 산 - 촉매 반응을 통해 실리카 나노 입자의 제조

Microwave-assisted synthetic techniques were used to quickly and reproducibly produce silica nanoparticle sols using an acid catalyst with nanoparticle ...

Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile N-(2-alkoxyvinyl)sulfonamides, which react under a variety of conditions to afford useful N- and O-containing compounds. Acid-catalyzed addition of alcohols or thiols to N-(2-alkoxyvinyl)sulfonamide-containing phthalans provides access to ketals and thioketals, respectively. Selective reduction of the vinyl group in N-(2-alkoxyvinyl)sulfonamide-containing phthalans via hydrogenation yields the corresponding phthalan in good yield, whereas reduction with sodium bis(2-methoxyethoxy)aluminumhydride generates a ring-opened phenethylamine analogue. Because the N-(2-alkoxyvinyl)sulfonamide functional group is synthetically versatile, but often hydrolytically unstable, this protocol emphasizes key techniques in preparing, handling, and reacting these pivotal substrates in several useful transformations.

Preparation of N-2-alkoxyvinylsulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

Representative experimental procedures for the synthesis of N-(2-alkoxyvinyl)sulfonamides and subsequent conversion to phthalan and phenethylamine derivatives are presented in detail.

N의 준비-(2-alkoxyvinyl) sulfonamides N-토실기-1,2,3-triazoles 및 후속 변환 대체 Phthalans 및 Phenethylamines에서

Decomposition of N-tosyl-1,2,3-triazoles with rhodium(II) acetate dimer in the presence of alcohols forms synthetically versatile ...

Reducing Willow Wood Fuel Emission by Low Temperature Microwave Assisted Hydrothermal Carbonization

Biomass is a sustainable fuel, as its CO2 emissions are reintegrated in biomass growth. However, the inorganic precursors in the biomass cause a negative environmental impact and slag formation. The selected short rotation coppice (SRC) willow wood has a high ash content (<img alt="Equation 1" src="/files/ftp_upload/58970/58970eq1.jpg" /> = 1.96%) and, therefore, a high content of emission and slag precursors. Therefore, the reduction of minerals from SRC willow wood by low temperature microwave assisted hydrothermal carbonization (MAHC) at 150 &#176;C, 170 &#176;C, and 185 &#176;C is investigated. An advantage of MAHC over conventional reactors is an even temperature conductance in the reaction medium, as microwaves penetrate the whole reactor volume. This allows a better temperature control and a faster cooldown. Therefore, a succession of depolymerization, transformation and repolymerization reactions can be analyzed effectively. In this study, the analysis of the mass loss, ash content and composition, heating values and molar O/C and H/C ratios of the treated and untreated SCR willow wood showed that the mineral content of the MAHC coal was reduced and the heating value increased. The process water showed a decreasing pH and contained furfural and 5-methylfurfural. A process temperature of 170 &#176;C showed the best combination of energy input and ash component reduction. The MAHC allows a better understanding of the hydrothermal carbonization process, while a large-scale industrial application is unlikely because of the high investment costs.

A protocol for the emission precursor depletion from low quality biomass by low temperature microwave assisted hydrothermal carbonization treatment is presented. This protocol includes the microwave parameters and the analysis of the biocoal product and process water.

저온 마이크로파 보조 열 량 화에의 한 버드 나무 연료 방출 감소

Biomass is a sustainable fuel, as its CO2 emissions are reintegrated in biomass growth. However, the inorganic precursors in the biomass cause a negative ...

Synthesis of In37P20(O2CR)51 Clusters and Their Conversion to InP Quantum Dots

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 clusters have been observed as intermediates in the synthesis of InP quantum dots from molecular precursors (In(O2CR)3, HO2CR, and P(SiMe3)3) and may be isolated as a pure reagent for subsequent study and use as a single-source precursor. These clusters readily convert to crystalline and relatively monodisperse samples of quasi-spherical InP quantum dots when subjected to thermolysis conditions in the absence of additional precursors above 200 &#176;C. The optical properties, morphology, and structure of both the clusters and quantum dots are confirmed using UV-Vis spectroscopy, photoluminescence spectroscopy, transmission electron microscopy, and powder X-ray diffraction. The molecular symmetry of the clusters is additionally confirmed by solution-phase 31P NMR spectroscopy. This protocol demonstrates the preparation and isolation of atomically-precise InP clusters, and their reliable and scalable conversion to InP QDs.

Synthesis of In37P20O2CR51 Clusters and Their Conversion to InP Quantum Dots

A protocol for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots is presented.

37P 20(o2CR)51 클러스터의 합성 및 InP 양자 점으로의 변환

This text presents a method for the synthesis of In37P20(O2C14H27)51 clusters and their conversion to indium phosphide quantum dots. The In37P20(O2CR)51 ...

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it efficient in both time and resources and utilizes water as the solvent. 3-Aminocrotononitrile or an appropriate &#945;-cyanoketone is combined with an aryl hydrazine and dissolved in 1 M HCl. The mixture is then heated in a microwave reactor at 150 &#176;C, typically for 10-15 min. The product can be readily obtained by basifying the solution with 10% NaOH and isolating the desired compound with a simple vacuum filtration. The use of water as a solvent in this reaction lends to its ease and utility in production, and this method is easily reproducible with a variety of functional groups. Typical isolated yields range from 70-90%, and reactions can be performed on the milligram to gram scale with little to no change in observed yields. Some of the applications of these molecules and their derivatives include pesticides, anti-malarials, and chemotherapeutics, among many others.

Microwave-Assisted Preparation of 1-Aryl-1H-pyrazole-5-amines

1-Aryl-1H-pyrazole-5-amines are prepared from aryl hydrazines combined with either 3-aminocrotononitrile or an &#945;-cyanoketone in a 1 M HCl solution using a microwave reactor. Most reactions are done in 10-15 minutes and pure product can be obtained via vacuum filtration with typical isolated yields of 70-90%.

1-아릴-1 H-피라졸-5-아민의 전자레인지 보조 제제

A synthetic process for the preparation of a variety of 1-aryl-1H-pyrazole-5-amines was developed. The microwave-mediated nature of this method makes it ...

Hierarchical and Programmable One-Pot Oligosaccharide Synthesis

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for generating potential synthetic solutions. The programmable one-pot oligosaccharide synthesis approach is designed to empower fast oligosaccharide synthesis of large amounts using thioglycoside building blocks (BBLs) with the appropriate sequential order of relative reactivity values (RRVs). Auto-CHO is a cross-platform software with a graphical user interface that provides possible synthetic solutions for programmable one-pot oligosaccharide synthesis by searching a BBL library (containing about 150 validated and &#62;50,000 virtual BBLs) with accurately predicted RRVs by support vector regression. The algorithm for hierarchical one-pot synthesis has been implemented in Auto-CHO and uses fragments generated by one-pot reactions as new BBLs. In addition, Auto-CHO allows users to give feedback for virtual BBLs to keep valuable ones for further use. One-pot synthesis of stage-specific embryonic antigen 4 (SSEA-4), which is a pluripotent human embryonic stem cell marker, is demonstrated in this work.

This protocol demonstrates how to use the Auto-CHO software for hierarchical and programmable one-pot synthesis of oligosaccharides. It also describes the general procedure for RRV determination&#160;experiments and one-pot glycosylation of SSEA-4.

계층적 및 프로그래밍 가능한 원팟 올리고사카라이드 합성

This article presents a general experimental protocol for programmable one-pot oligosaccharide synthesis and demonstrates how to use Auto-CHO software for ...

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products and notably to generate chiral carbon centers. The crucial first step consists in the selective double hydroboration of CO2 catalyzed by an iron hydride complex. The product obtained with this 4 e- reduction is a rare bis(boryl)acetal, compound 1, which is subjected in situ to three different reactions in a second step. The first reaction concerns a condensation reaction with (diisopropyl)phenylamine affording the corresponding imine 2. In the second and third reaction, intermediate 1 reacts with triazol-5-ylidene (Enders&#39; carbene) to afford compounds 3 or 4, depending on the reaction conditions. In both compounds, C-C bonds are formed, and chiral centers are generated from CO2 as the only source of carbon. Compound 4 exhibits two chiral centers obtained in a diastereoselective manner in a formose-type mechanism. We proved that the remaining boryl fragment plays a key role in this unprecedented stereocontrol. The interest of the method stands on the reactive and versatile nature of 1, giving rise to various complex molecules from a single intermediate. The complexity of a two-step method is compensated by the overall short reaction time (2 h for the larger reaction time), and mild reaction conditions (25 &#176;C to 80 &#176;C and 1 to 3 atm of CO2).

Versatile CO2 Transformations into Complex Products: A One-pot Two-step Strategy

CO2 transformations are conducted in a one-pot two-step procedure for the synthesis of complex molecules. The selective 4 e- reduction of CO2 with a hydroborane reductant affords a reactive and versatile bis(boryl)acetal intermediate which is subsequently involved in condensation reaction or carbene-mediated C-C coupling generation.

다재다능한CO2를 복합 제품으로 전환: 원포트 2단계 전략

CO2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of value-added products ...

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal catalysis, the literature on direct heteroarylation is scarce. The presence of heteroatoms such as nitrogen, sulfur and oxygen often make heteroarylation a challenging research field due to catalyst poisoning, product decomposition and the rest. This protocol details a highly efficient direct &#945;-C(sp3) heteroarylation of ketones under microwave irradiation. Key factors for successful heteroarylation include the use of XPhos Palladacycle Gen. 4 Catalyst, excess base to suppress side reactions and the high temperature and pressure achieved in a sealed reaction vial under microwave irradiation. The heteroarylation compounds prepared by this method were fully characterized by proton nuclear magnetic resonance spectroscopy (1H NMR), carbon nuclear magnetic resonance spectroscopy (13C NMR) and high-resolution mass spectrometry (HRMS). This methodology has several advantages over literature precedents including broad substrate scope, rapid reaction time, greener procedure and operational simplicity by eliminating the preparation of intermediates such as silyl enol ether. Possible applications for this protocol include, but are not limited to, diversity-oriented synthesis for the discovery of biologically active small molecules, domino synthesis for the preparation of natural products and ligand development for new transition metal catalytic systems.

Heteroaryl compounds are important molecules utilized in organic synthesis, medicinal and biological chemistry. A microwave-assisted heteroarylation using palladium catalysis provides a rapid and efficient method to attach heteroaryl moieties directly to ketone substrates.

전이 금속 촉매를 이용한 케톤 전자레인지 보조 직접 이질화

Heteroarylation introduces heteroaryl fragments to organic molecules. Despite the numerous available reactions reported for arylation via transition metal ...

한 냄비 전자 렌지를 이용한 변환 Anomeric 질 산 에스테 르의 Trichloroacetimidates

요약

더 많은 비디오 탐색

이 비디오의 챕터