המחברים רוצה להכיר אוניברסיטת ואנדרבילט ו המכון לביולוגיה כימיים עבור תמיכה כספית. מר ברקלי אליס, פרופסור ג'ון מקלין הם הכירו עבור ניתוח ספקטרלי של מסה להדפסה ברזולוציה גבוהה.

1. נציג מיקרוגל-בסיוע Denitration
<ol><li>במקום אסתר חנקת azido (1.0 equiv., 0.2 mmol) בתוך המבחנה התגובה מיקרוגל 8 מ ל. ניתן להגדיל את היקף התגובה ל mmol מספר ללא כל השפעה שלילית על התקדמות התגובה.</li>
	<li>להמיס אסתר azido-ניטראט ב 20% aq. אצטון (0.1 M, 2.0 מ"ל). פירידין (5.0 equiv., 0.08 מל ', 1.0 mmol) להוסיף מיכל התגובה. וחוץ את המבחנה הקרנה במיקרוגל ולמקם את מיכל התגובה חור בכור מיקרוגל.</li>
	<li>. להאיר את הפתרון ב- 120 מעלות למשך 15 דקות עם ערבוב, עם זמן המתנה קבועה... הזמן מייצג כמה זמן ההקרנות תתרחש ב המיועד טמפרטורה, לחץ תוצאות. מחממים את כל התגובות הטמפרטורה המדווחת ramping במשך 2 דקות. נטר את הטמפרטורה על ידי חיישן מוכלת IR.</li>
	<li>לאחר 15 דקות, לנתח את תערובת התגובה באמצעות שכבה דקה כרומטוגרפיה (TLC) כדי לאשר את הצריכה של חומר המוצא. להשתמש אתיל אצטט 1:1 / hexanes eluent.<ol>
<li>דמיינו את הצלחת TLC באמצעות הכתם molybate אמוניום ceric. Rf של מגיבים, המוצר עשוי להשתנות, אך האלכוהול תוך צמצום בדרך כלל 0.05 ל 0.1 התחתון Rf מאשר מגיבים.</li>
	</ol>
</li>
</ol>2. היווצרות trichloroacetimidate
<ol><li>בעקבות צריכת מוחלטת של חומר המוצא, להתנדף הממס לאמצעי אחסון מופחת באמצעות חברת תעופה. לאחר מכן, לדלל עם (דיכלורומתאן) CH2Cl2 (1.0 מ"ל) והשתמש מזרק כדי להסיר את שכבת מים. לאחר הסרת השכבה מים, מגניב את תערובת התגובה עד 0 ° C בעזרת אמבט קרח-מים.</li>
	<li>לאחר מכן, להוסיף DBU (10 eq, 0.3 mL, 1.9 mmol) ו- 2,2,2-trichloroacetonitrile (50 eq, 1.0 מ"ל, 10 mmol) מיכל התגובה. ריאגנטים הן מתווספות עודף, מינימום של המקבילה בסיס 1 ו- 1 המקבילה 2,2,2-trichloroacetonitrile יש צורך.</li>
	<li>לאפשר את תערובת התגובה לעורר בעת ההתחממות לטמפרטורת הסביבה. נטר את התגובה על ידי TLC לאשר הצריכה של חומר המוצא.<ol>
<li>להשתמש אתיל אצטט 1:1 / hexanes eluent. דמיינו את הצלחת TLC באמצעות הכתם molybate אמוניום ceric. Rf של מגיבים ושל המוצר ישתנו.</li>
	</ol>
</li>
	<li>לאחר צריכת מלאה החל חומר, להעביר את תערובת התגובה בקבוקון שחזור ולרכז את התערובת ב vacuo ב- 30 ° C. אידוי של הממס תספק צהוב חיוור גולמי שמן חום.</li>
	<li>לטהר את המוצר גולמי על ידי סיליקה ג'ל עמודה כרומטוגרפיה ועם לעמודה כרומטוגרפיה 1.5 ס מ 1:4 אתיל אצטט/hexanes כמו eluent. הצורה הפיזי של imidate ישתנו מולקולה מולקולה.</li>
</ol><img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/56610/56610fig1v3.jpg"> איור 1. דוגמאות מייצגות של ההמרה סיר אחד של 2-azido-1-ניטראט אסטרים ל- 2-azido-1-trichloroimidates. <a href="//cloudflare.jove.com/files/ftp_upload/56610/56610fig1v3large.jpg" target="_blank">אנא לחץ כאן כדי להציג גירסה גדולה יותר של הדמות הזאת.</a>

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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. 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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. 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המחברים יש אין אינטרסים כלכליים מתחרים.

הפרוטוקול המתואר במדריך זה מספק שיטה להמרת חנקתי אסטרים פונקציונליות שימושית, תגובתי. במובן רחב יותר, העסקת כור מיקרוגל להשלמת תמרונים ספציפי במהלך סינתזה פחמימות יש פוטנציאל להפוך שינויי צורה קשה נתיישב, שגרתיות. מטרתנו במדריך זה כדי להדגים כיצד להתמודד עם פחמימות בהקשר של הקרנה במיקרו?...

עקב המצאות שלהם בכל מקום ב ביולוגיה מולקולרית, פחמימות היו מטרות ארוכת שנים עבור סינתזה. 1 , 2 , 3 -הליבה של כל קמפיין מוצלח סינתטי הוא פריסה נכונה של גליקוזילציה תגובות לבנות את השרשרת פחמימה # מיון הפחמימות. 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 . באופן לא מפתיע, ישנם מספר רב של שיטות כדי להתקין את glycosidic אגרות חוב. 13 , 14 בשיטה Koenigs-קנור הוא אחד מההליכים הידוע המוקדם, כרוך צימוד של כלוריד glycosyl או ברומיד עם מרכיב אלכוהולי, בדרך כלל תחת הפעלת מתכות כבדות (כספית או כסף). 15 ופלואורידים glycosyl קשורים הוכנסו הראשון בתור תורמים בשנת 1981 על ידי קבוצת Mukaiyama, מצאו יישום נרחב עקב יציבות מוגברת שלהם תרמי וכימיים. 16 בקצה השני של הספקטרום תגובתיות הם glycosyl iodides, אשר מגיב הרבה יותר מאשר הלידים אחרים. תגובתיות מוגברת מלווה stereocontrol מוגברת, במיוחד כאשר ויוצרים מקושרים-α oligosaccharides. 17 בנוסף "haloglycosides", thioglycosides מצאו כלי רחב, בין השאר, הודות לקלות שלהם היווצרות, יציבות כדי שפע של תנאי ריאקציה, והפעלה עם ריאגנטים electrophilic. 18
השיטות המתוארות לעיל פוקוס על המרת anomeric אלכוהול כדי, המכילים "-חמצן" החבויים עוזב קבוצה מופעל, בסופו של דבר שנעקרו על ידי אלכוהול מ מולקולה מקבל. Anomeric חמצן הפעלה כפי שתואר על ידי בית הספר שמידט, מתמקד המרת החמצן C1 עצמו, קבוצה עוזבת. 19 בשיטה זו היא החזקה ביותר, בשימוש נרחב תגובות כימיות גליקוזילציה. Trichloroacetimidate תורמים מוכנים ברצון הפחתת סוכר, trichloroacetonitrile בנוכחות בסיס כגון אשלגן פחמתי (K2CO3) או 1, 8-diazabicyclo [5.4.0] undec-7-ene (DBU). מינים אלה מופעלים באמצעות חומצות לואיס. 20
לאחרונה, אנחנו דיווחו על כך להיות מוכן ישירות תורמים 2-azido-1-trichloroacetimidate מ- glycals. התהליך כרוך ריאקציה שני, נוהל סיר אחד מ- 2-azido-1-ניטראט אסטרים. 21 פרוטוקול מפורט זה נועד לסייע למטפלים בהצלחה להשלים את השינוי בתשואה גבוהה. עניין מיוחד הוא הצעד הראשון של הרצף, אשר מתמקדת denitration תרמי תחת מיקרוגל - בסיוע חימום. אנו גם מקווים לספק מדריך חזותי על העסקת מיקרוגל כורים ב סינתזה אורגנית.

<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

מטרת ההליך הבא נועד לספק הפגנה של ההמרה סיר אחד של 2-azido-1-חנקת-אסתר תורם glycosyl trichloroacetimidate. בעקבות azido-ניטרציה של glycal, אסתר 2-azido-1-ניטראט מוצר יכול להיות הידרוליזה תחת הקרנה בסיוע מיקרוגל. שינוי זה מושגת בדרך כלל בעזרת ריאגנטים חריפה נוקלאופילי, זמני תגובה ארוכים. הקרנה במיקרוגל גורם הידרוליזה, בהיעדרו של ריאגנטים, עם זמני תגובה קצרים. בעקבות denitration, מומר האלכוהול anomeric ביניים, בסיר אותה המקביל 2-azido-1-trichloroacetimidate.

הטכנולוגיה המתוארים בזאת הודגם על מאגר של שלושה אסטרים 2-azido-1-חנקתי. בכל מקרה ומקרה הושלם השלב הראשון של התגובה תוך 20 דקות.
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/56610/56610fig2v3.jpg"> איור 2- נציג דוגמה הידרוליזה (1 ->2), סיר אחד ...

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

סיר אחד בסיוע מיקרוגל ההמרה של חנקת Anomeric-אסטרים Trichloroacetimidates

2-azido-1-חנקת-אסתר ניתן להמיר את המקביל 2-azido-1-trichloroacetimidate בהליך סיר אחד. המטרה של כתב היד היא להדגים את השירות של הכור מיקרוגל בסינתזה של פחמימות.

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 Views.  Vanderbilt University. 2-azido-1-חנקת-אסתר ניתן להמיר את המקביל 2-azido-1-trichloroacetimidate בהליך סיר אחד. המטרה של כתב היד היא להדגים את השירות של הכור מיקרוגל בסינתזה של פחמימות.

Video: 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.

מיקרוגל בסיוע תגובות Dehydrogenative intramolecular דילס-Alder לסינתזה של Naphthalenes הפונקציונלי / צבעי Solvatochromic

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

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.

Functionalization בסיוע מיקרוגל של פולי (אתילן גליקול) ופפטידים על השרף לשימוש בPolymerizations שרשרת וגיבוש Hydrogel

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.

הכנה של חלקיקי סיליקה באמצעות חומצה קטליזה בסיוע מיקרוגל

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.

הכנת N-(2-alkoxyvinyl) sulfonamides N- tosyl-1,2,3-triazoles, הבאים ההמרה ל שהוחלפו Phthalans ו- Phenethylamines

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.

הפחתת הדלק של ווילו ווד על ידי מיקרוגל טמפרטורה נמוכה בסיוע הידרותרמי פחמון

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.

סינתזה של37P20(O2CR)51 אשכולות ההמרה שלהם נקודות קוונטום inp

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%.

הכנת בעזרת מיקרוגל של 1-Aryl-1H-קורטידול-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 ...

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.

הירארכי וניתן לתיכנות Oligosaccharide סינתזה של סיר אחד

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.

CO רב-תכליתי2 העתקות לתוך מוצרים מורכבים: אחד-סיר 2-צעד אסטרטגיה

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.

מיקרוגל בסיוע ישיר הטרולציה של Ketones באמצעות מתכת מעבר זרז

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