这项工作得到韩国国家研究基金会 (NRF-2012M3A7B4049645 和 HUFS 研究基金 (2018) 的支持。

1. 合成 (6R)-1-[(R)-1-苯)-1-Azoniabicyclo [4.1. 0] 庚烷磺酸盐 (4)
<ol><li>4-(R)-[1-(r)-1-苯) aziridin 2-基] 丁基 4-磺酸盐 (2) 的合成<ol>
<li>添加100毫克 4-[(r)-1-(r)-1-苯) aziridin-2-基] 氨基正丁-1-ol (1)12 (0.46 毫摩尔, 1.0 equiv), 140 µL 的三乙胺 (Et3N, 1.0 毫摩尔, 2.2 equiv), 和一个磁搅拌棒成烤箱干25毫升双颈圆底烧瓶在氮气 (N2) 大气之下。</li>
		<li>用密闭注射器将无水二氯甲烷 (CH2氯2, 5 毫升) 加入到反应瓶中。</li>
		<li>冷却反应混合物在0°c 使用冰浴和搅动混合物5分钟。</li>
		<li>将对磺酸酐 (164 毫克, 0.50 毫摩尔, 1.10 equiv) 加入到反应混合物中, 再搅拌45分钟。</li>
		<li>将反应混合物加热室温 (RT), 搅拌30分钟。</li>
		<li>用薄层色谱 (TLC) 监测反应, 使用 hexanes: 乙酸乙酯 (EtOAc) (1:1 伏/v, 保留因子 Rf = 0.55) 作为淋洗。</li>
		<li>在开始的酒精的完全消耗量以后1, 淬火反应混合物与水 (5 毫升)。采用 CH2Cl2 (3 x 15 毫升) 提取异质混合物, 在无水硫酸钠 (Na2至4) 上干燥复合有机层, 用于10分钟, 并在真空中使用旋转蒸发器进行浓缩。</li>
		<li>用 hexanes 与闪光柱层析洗脱法提纯原油产品: EtOAc (2:1 至1:2 伏/v), 可负担165毫克 (0.44 毫摩尔, 96% 产量) 4-(R)-[1-(r)-1-苯) aziridin-2-基] 丁基 4-磺酸盐 (rf= 0.55, hexanes: EtOAc (1:1 伏/v)) 作为粘性液体。</li>
	</ol>
</li>
	<li>合成 (6R)-1-[(R)-1-苯)-1-azoniabicyclo [4.1. 0] 庚烷磺酸盐 (4)<ol>
<li>转移5毫克的新鲜准备2在核磁共振管和添加乙腈 d3 (CD3CN, 300 µL)。</li>
		<li>保持上述溶液在 RT 为24小时, 以达到完全转化为 (6R)-1-[(R)-1-苯)-1-azoniabicyclo [4.1. 0] 庚烷磺酸盐4。</li>
		<li>在 CD3CN 的不同时间点 (10 分钟、1、5、7和 24 h) 中, 通过核磁共振 (NMR) 频谱监测2到4的转换。</li>
	</ol>
</li>
</ol>2. 扩大 1-Azoniabicyclo [4.1. 0] 庚烷磺酸盐的一般程序
<ol><li>使用步骤 1.1.1 1.1.7 准备相应的磺酸盐2。</li>
	<li>将上述粗磺酸盐, 并将磁性搅拌棒放入烤箱干燥的25毫升圆底烧瓶中。</li>
	<li>使用密闭注射器将无水 CH3CN (4.0 毫升) 添加到反应瓶中。</li>
	<li>将相应的亲核试剂 (1.37 毫摩尔, 3.0 equiv) 添加到反应混合物中, 搅拌 8-15 h。</li>
	<li>淬火反应混合物与水 (5 毫升), 萃取物与 CH2Cl2 (3 x 15 毫升), 干燥的有机层在无水 Na2如此4 , 并集中在真空使用旋转蒸发器。</li>
	<li>用柱层析法提纯原油产品: EtOAc (19:1 至 7:3 hexanes), 以支付纯环膨胀产品。 注: 所有化合物均采用上述程序合成, 除6j (入口 j,表 1)。 注意: 干燥 CH3CN 是由氢化钙 (2) 在 N2大气中蒸馏而成。氰化钠在已知的最有毒物质中是有毒的, 在化学油烟机下使用适当的安全防护。用高锰酸钾 (KMnO4) 溶液对氰进行淬火。</li>
</ol>3. 合成 (S)-1-[(R)-1-苯] azepan 3 醇 (6j)
<ol><li>转移 4-(r)-[1-(r)-1-苯) aziridin 2-基] 丁基 4-磺酸盐 (100 毫克, 0.27 毫摩尔, 1.0 equiv), 和一个磁搅拌棒成烤箱干燥25毫升的圆底烧瓶装有回流冷凝器。</li>
	<li>用注射器将 14-二恶烷 (4 毫升) 加入到反应瓶中。</li>
	<li>加入0.4 毫升2.0 米氢氧化钠溶液 (氢氧化钠, 0.80 毫摩尔, 3.0 equiv) 到反应混合物和热回流为 2.0 h。</li>
	<li>淬火反应混合物与水 (4 毫升), 萃取物与 CH2Cl2 (4 x 15 毫升), 干燥的有机层在无水 Na2如此4 , 并集中在真空使用旋转蒸发器。</li>
	<li>用 hexanes 的柱层析洗脱法提纯原油产品: EtOAc (2:1 至 1:1 (v/v)) (Rf = 0.60, hexanes: EtOAc (1:1 (v/v)), 可负担46毫克 (S)-1-[(R)-1-苯] azepan 3 醇 (0.21 毫摩尔, 79% 产量)。</li>
</ol>4. 合成 [(2R, 3r, 4r)-34-双 (苄)-1-(S)-1-苯) 哌-2-基] 乙酸甲酯 (8):
<ol><li>转移 (3r, 4r)-34-双 (苄)-4-[(R)-1-(S)-1-苯) aziridin-2-基] 氨基正丁-1-ol (7) (220 毫克, 0.51 毫摩尔, 1.0 equiv), 180 µL Et3N (1.27 毫摩尔, 2.5 equiv), 和一个磁性搅拌棒成烤箱干燥25毫升双颈圆底烧瓶在 N2的气氛下。</li>
	<li>使用密闭注射器将无水 CH2氯2 (4 毫升) 添加到反应瓶中。</li>
	<li>冷却反应混合物在0°c 和搅动5分钟。</li>
	<li>将对磺酸酐 (200 毫克, 0.61 毫摩尔, 1.20 equiv) 加入到反应混合物中, 再搅拌45分钟。</li>
	<li>将反应混合物加热至 RT, 搅拌30分钟。</li>
	<li>用 hexanes: EtOAc (7:3 伏/五, Rf = 0.60) 作为淋洗, 监测反应的进展。</li>
	<li>在酒精的完全消耗量7以后, 淬火反应混合物与水 (5 毫升), 萃取物与 CH2Cl2 (3 x 15 毫升), 干燥联合有机层数在无水 Na2如此4和集中在真空使用旋转蒸发器。</li>
	<li>将上述粗磺酸盐, 并将磁性搅拌棒放入烤箱干燥的25毫升圆底烧瓶中。</li>
	<li>使用密闭注射器将无水 CH3CN (4 毫升) 添加到反应瓶中。</li>
	<li>将125毫克醋酸钠 (NaOAc, 1.53 毫摩尔, 3.0 equiv) 加入到反应混合物中, 搅拌12小时。</li>
	<li>淬火反应混合物与水 (5 毫升), 萃取物与 CH2Cl2 (3 x 15 毫升), 干燥的有机层在无水 Na2如此4 , 并集中在真空使用旋转蒸发器。</li>
	<li>用柱层析法提纯粗产品: EtOAc (9:1 至4:1 伏/v), 以 hexanes 纯化合物 8 (200 毫克, 83% 产量)。</li>
</ol>5. 合成 (3R, 4r)-3-叠氮基-1-[(R)-1-苯] azepan-4-Ol (14):
<ol><li>转移 (r)-1-[(S)-1-(r)-1-苯) aziridin 2-基] 丁烷-14-二醇 (13) (235 毫克, 1.0 毫摩尔, 1.0 equiv), 0.35 毫升 Et3N (2.50 毫摩尔, 2.5 equiv), 和一个磁搅拌棒成烤箱干25毫升双颈圆底烧瓶在氮气气氛下。</li>
	<li>用密闭注射器将无水 CH2Cl2 (8 毫升, 0.12 米) 添加到反应瓶中。</li>
	<li>冷却反应混合物在0°c 和搅动5分钟。</li>
	<li>将对磺酸酐 (359 毫克, 1.10 毫摩尔, 1.10 equiv) 加入到反应混合物中, 再搅拌45分钟。</li>
	<li>用 hexanes: EtOAc (1:1 伏/五, Rf = 0.40) 作为淋洗, 监测反应的进展。</li>
	<li>在开始酒精的完全消耗量以后13, 淬火反应混合物与水 (10 毫升), 萃取物与 CH2Cl2 (3 x 15 毫升), 干燥联合有机层数在无水 Na2如此4和集中在真空使用旋转蒸发器。</li>
	<li>将上述粗磺酸盐, 并将磁性搅拌棒放入烤箱干燥的25毫升圆底烧瓶中。</li>
	<li>使用密闭注射器将无水 CH3CN (8 毫升, 0.12 米) 添加到反应瓶中。</li>
	<li>加入214毫克的 NaOAc (3.30 毫摩尔, 3.30 equiv) 的反应混合物和搅拌 12 h。</li>
	<li>将反应混合物与水 (10 毫升) 淬火, 萃取物与 CH2Cl2 (15 毫升 x 3 倍), 干燥的有机层在无水 Na2如此4 , 并集中在真空使用旋转蒸发器。</li>
	<li>用柱层析法提纯粗产品: EtOAc (9:1 至4:1 伏/v), 以 hexanes 纯化合物14 (133 毫克, 51% 产量)。</li>
</ol>6. 所有产品的特性
<ol><li>用1H、 13C 核磁共振波谱和高分辨率质谱 (HRMS) 表征了所有新化合物。</li>
</ol>

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作者声明没有竞争的财政利益。

哌啶和 azepane 是 azaheterocycles 许多救生药物和抗生素中最丰富的两种, 包括各种生物活性天然产物16。为了获得 enantiopure 哌啶 (5) 和 azepane (6) 与不同的取代基, 我们得以一个有效的合成方法通过形成 1-azoniabicyclo [4.1. 0] 庚烷磺酸盐从 entiopure 2-(4-丁基)aziridne 其次是 regiospecific 亲核攻击在桥梁或在桥头碳。在乙腈中溶解相应的 2-(4-tosyloxybutyl) 氮丙啶, 容易制备...

在三元循环化合物中, 氮丙啶具有类似的环应变能, 如丙烷和环氧乙烷, 可通过环形开口1、2、3来承受各种含氮循环和非环状化合物。然而, 氮丙啶的特性和反应性取决于环氮的取代基。氮丙啶与一个电子撤退的小组在圆环氮气4, 被叫 "激活的氮丙啶", 被激活与接踵而来的亲核试剂反应, 不用任何另外的活化试剂。另一方面, "非活化氮丙啶" 与电子捐赠取代基在氮气是相当稳定和惰性的亲核试剂, 除非它被激活作为一个 aziridinium 离子作为Ia (图 1a)5,6,7. 非活化氮丙啶环的开启取决于各种因素, 如 C2 的取代基和氮丙啶的 C3 碳、亲电性激活氮丙啶环和传入的亲核试剂。由于亲核试剂对开环反应的高反应性, aziridinium 离子的分离和表征是不可能的, 但它的形成和特征 spectroscopically 与非亲核反负离子5,8,9,10. aziridinium 离子的立体环开放反应由适当的亲核试剂产生含氮非循环有价值分子 (pi和pii)5, 6,7,8,9,10。
同样, 笼 aziridinium 离子 (Ib) 可能是通过去除组内的氮丙啶环氮的亲核攻击而产生的 (图 1b)。然后, 该中间体通过环应变的释放与传入亲核试剂进行环形扩展。笼 aziridinium 离子的形成和稳定性取决于许多因素, 如取代基、环的大小和溶剂介质9。氮丙啶环扩展的立体选择性是其综合效用的一个关键方面, 它依赖于起始基板的取代性和应用亲核试剂的特性。
在我们早期的研究中, 我们成功地准备了 1-azoniabicyclo [3.1. 0] 己烷磺酸盐Ib (n = 1), 其随后的环扩张导致了吡咯烷和哌啶的形成 (piii和piv, n= 1,图 1)8。作为我们继续研究笼 aziridinium 离子化学的一部分, 我们在这里描述了 1-azoniabicyclo [4.1. 0] 庚烷磺酸盐Ib (n = 2) 的形成, 作为一个代表性的例子。这是由 2-(4-toluensulfonyloxybutyl) 氮丙啶和它的圆环扩展被触发由亲核试剂负担得起价值的哌啶和 azepane (pi和pii, n = 2,图 1) 以各种各样的取代在圆环11附近。enantiopure 氮丙啶 4-[(r)-1 (r)-1-苯) aziridin 2 基] 氨基正丁-1-ol (1) 的扩环导致取代 azaheterocycles 的不对称合成, 适用于生物具有哌啶和 azepane 骨架的活性分子。该合成协议已应用于各种化合物, 从简单的 2-cyanomethylpiperidine 5f, 2-acetyloxymethylpiperidine 5h和 3-hydroxyazepane 6j到更复杂的分子, 包括自然产品如 fagomine (9), febrifugine 模拟 (12) 和 balanol (15) 在光学纯净的形式11。

<table border="0" cellpadding="0" cellspacing="0" width="1213">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Thin Layer Chromatography (TLC)</td>
			<td style="width:260px;">Merck</td>
			<td style="width:207px;">100390</td>
			<td style="width:183px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">UV light</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td>Z169625-1EA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Bruker AVANCE III HD (400 MHz) spectrometer</td>
			<td style="width:260px;">Bruker</td>
			<td style="width:207px;">NA</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">JASCO P-2000</td>
			<td style="width:260px;">JASCO</td>
			<td style="width:207px;">P-2000</td>
			<td>For optical rotation</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">High resolution mass spectra/ MALDI-TOF/TOF Mass Spectrometry</td>
			<td style="width:260px;">AB SCIEX</td>
			<td style="width:207px;">4800 Plus&#160;</td>
			<td>High resolution mass spectra</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">(2R)-1-[(1R)-1-Phenylethyl]-2-aziridinecarboxylic acid (&#8211;)-menthol ester, 98%</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:207px;">57,054-0</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">(2S)-1-[(1R)-1-Phenylethyl]-2-aziridinecarboxylic acid (&#8211;)-menthol ester</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:207px;">57,051-6</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Triethylethylamine</td>
			<td style="width:260px;">DAEJUNG</td>
			<td style="width:207px;">8556-4400-1L</td>
			<td>CAS No: 121-44-8</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Dichloromethane</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">M0822-18L</td>
			<td>CAS No: 75-09-2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">p-Toluenesulfonic anhydride</td>
			<td style="width:260px;">Sigma-Aldrich</td>
			<td style="width:207px;">259764-25G</td>
			<td>CAS No: 4124-41-8</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">n-Hexane</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">H0114-18L</td>
			<td>CAS No: 110-54-3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Ethyl acetate</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">E0191-18L</td>
			<td>CAS No: 141-78-6</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium sulfate</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">S1011-1kg</td>
			<td>CAS No: 7757-82-6</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Acetonitrile-d3</td>
			<td style="width:260px;">Cambridge Isotope Laboratories, Inc</td>
			<td style="width:207px;">15G-744-25g</td>
			<td>CAS No: 2206-26-0</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Acetonitrile</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">A0127-18L</td>
			<td>CAS No: 75-05-8</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">1,4-Dioxane</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">D0654-1kg</td>
			<td>CAS No: 123-91-1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium hydroxide</td>
			<td style="width:260px;">DUKSAN</td>
			<td style="width:207px;">A31226-1kg</td>
			<td>CAS No: 1310-73-2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium acetate</td>
			<td style="width:260px;">Alfa Aesar</td>
			<td style="width:207px;">11554-250g</td>
			<td>CAS No: 127-09-3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Lithium aluminum hydride</td>
			<td style="width:260px;">TCI</td>
			<td style="width:207px;">L0203-100g</td>
			<td>CAS No: 16853-85-3</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Tetrahydrofuran</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">T0148-18L</td>
			<td>CAS No: 109-99-9</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium azide</td>
			<td style="width:260px;">D.S.P</td>
			<td style="width:207px;">703301-500g</td>
			<td>CAS No: 26628-22-8</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Cesium fluoride</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">18951-0250-25g</td>
			<td>CAS No: 13400-13-0</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Tetrabutylammonium bromide</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">426288-25g</td>
			<td>CAS No: 1643-19-2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium iodide</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">383112-100g</td>
			<td>CAS No: 7681-82-5</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium cyanide</td>
			<td style="width:260px;">Acros Organics</td>
			<td style="width:207px;">424301000-100g</td>
			<td>CAS No: 143-33-9</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium thiocyanate</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">467871-250g</td>
			<td>CAS No: 540-72-7</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium methoxide</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">156256-1L</td>
			<td>CAS No: 124-41-4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Benzylamine</td>
			<td style="width:260px;">Alfa Aesar</td>
			<td style="width:207px;">A10997-1000g</td>
			<td>CAS No: 100-46-9</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Phenol</td>
			<td style="width:260px;">TCI</td>
			<td style="width:207px;">P1610-500g</td>
			<td>CAS No: 108-95-2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Sodium benzoate</td>
			<td style="width:260px;">Alfa Aesar</td>
			<td style="width:207px;">A15946-250g</td>
			<td>CAS No: 532-32-1</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:564px;">Chloroform-d</td>
			<td style="width:260px;">Cambridge Isotope Laboratories, Inc</td>
			<td style="width:207px;">DLM-7TB-100S/16H-239, 100g</td>
			<td>CAS No: 865-49-6</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Dimethyl sulfoxide-d6</td>
			<td style="width:260px;">Cambridge Isotope Laboratories, Inc</td>
			<td style="width:207px;">DLM-10-25, 25g</td>
			<td>CAS No: 2206-27-1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Methanol</td>
			<td style="width:260px;">SAMCHUN</td>
			<td style="width:207px;">M0585-18L</td>
			<td>CAS No: 67-56-1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Ninhydrin</td>
			<td style="width:260px;">Alfa Aesar</td>
			<td style="width:207px;">A10409-250g</td>
			<td>CAS No: 485-47-2</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">Phosphomolybdic acid hydrate</td>
			<td style="width:260px;">TCI</td>
			<td style="width:207px;">P1910-100g</td>
			<td>CAS No: 51429-74-4</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:564px;">p-Anisaldehyde</td>
			<td style="width:260px;">aldrich</td>
			<td style="width:207px;">A88107-5g</td>
			<td>CAS No: 123-11-5</td>
		</tr>
	</tbody>
</table>

preparation of stable bicyclic aziridinium ions and their ring-opening for the synthesis of azaheterocycles

笼 aziridinium 离子是通过在氮丙啶环中的氮原子的内部亲核攻击去除适当的离开群而产生的。笼 aziridinium 离子的效用, 特别是 1-azoniabicyclo [3.1. 0] 己烷和 1-azoniabicyclo [4.1. 0] 庚烷磺酸盐突出在氮丙啶环开口由亲核试剂与释放环应变产生相应的环扩张 azaheterocycles, 如吡咯烷, 哌啶和 azepane 与不同的取代基在环上的范围-和立体方式。在此, 我们报告了一个简单和方便的方法, 以制备稳定的 1-杂双环 [4.1. 0] 庚烷磺酸盐后, 选择性环开口通过亲核攻击无论是在桥梁或在桥头碳产生哌啶和 azepane环, 分别。这一综合策略使我们能够高效地制备含有哌啶和 azepane 的生物活性天然产物, 包括 sedamine、allosedamine、fagomine 和 balanol。

4-[(r)-1-(r)-1-苯) aziridin-2-基] 氨基正丁-1 醇 (1)12与p-磺酸酐和三乙胺的反应在 CH2Cl2在室温为 1.0 h 产生了相应的 2-(4-tosyloxybutyl) 氮丙啶2在96% 产量11。1在不同时间间隔内, 在 CD3CN 中, 2的 H NMR (400 兆赫) 频谱显示了 2-(4-tosyloxybutyl) 氮丙啶2到...

Watch this Scientific Journal Video about Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles at JoVE.com

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

稳定笼 Aziridinium 离子的制备及其开环 Azaheterocycles 的合成

笼 aziridinium 离子, 如 1-azoniabicyclo [4.1. 0] 庚烷磺酸盐是由 2-[4-tolenesulfonyloxybutyl] 氮丙啶, 用于制备替代的 piperidines 和 azepanes 通过地-和立体环形膨胀与各种亲核试剂。这一高效的协议允许我们准备各种 azaheterocycles, 包括自然产品, 如 fagomine, febrifugine 模拟和 balanol。

Bicyclic aziridinium ions were generated by the removal of an appropriate leaving group through internal nucleophilic attack by nitrogen atom in the ...

preparation-stable-bicyclic-aziridinium-ions-their-ring-opening-for

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Organic Chemistry

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Unit 1

Nucleophilic Substitution and Elimination Reactions of Alkyl Halides

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8.3K 次观看.  North Eastern Regional Institute of Science and Technology. 笼 aziridinium 离子, 如 1-azoniabicyclo [4.1. 0] 庚烷磺酸盐是由 2-[4-tolenesulfonyloxybutyl] 氮丙啶, 用于制备替代的 piperidines 和 azepanes 通过地-和立体环形膨胀与各种亲核试剂。这一高效的协议允许我们准备各种 azaheterocycles, 包括自然产品, 如 fagomine, febrifugine 模拟和 balanol。

视频: Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

Amide Coupling Reaction for the Synthesis of Bispyridine-based Ligands and Their Complexation to Platinum as Dinuclear Anticancer Agents

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. Isonicotinic acid, or its derivatives, are coupled to variable length diaminoalkane chains under an inert atmosphere in anhydrous DMF or DMSO with the use of a weak base, triethylamine, and a coupling agent, 1-propylphosphonic anhydride. The products precipitate from solution upon formation or can be precipitated by the addition of water. If desired, the ligands can be further purified by recrystallization from hot water. Dinuclear platinum complex synthesis using the bispyridine ligands is done in hot water using transplatin. The most informative of the chemical characterization techniques to determine the structure and gross purity of both the bispyridine ligands and the final platinum complexes is 1H NMR with particular analysis of the aromatic region of the spectra (7-9 ppm). The platinum complexes have potential application as anticancer agents and the synthesis method can be modified to produce trinuclear and other multinuclear complexes with different hydrogen bonding functionality in the bridging ligand.

This protocol describes the use of amide coupling reactions of isonicotinic acid and diaminoalkanes to form bridging ligands suitable for use in the synthesis of multinuclear platinum complexes, which combine aspects of the anticancer drugs BBR3464 and picoplatin.

酰胺偶联反应为双吡啶基配体及其络合合成，以白金为双核抗癌药物

Amide coupling reactions can be used to synthesize bispyridine-based ligands for use as bridging linkers in multinuclear platinum anticancer drugs. ...

科研

化学

Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties

We demonstrate a novel synthesis strategy for the preparation of Pr-doped SrTiO3 ceramics via a combination of solid state reaction and spark plasma sintering techniques. Polycrystalline ceramics possessing a unique morphology can be achieved by optimizing the process parameters, particularly spark plasma sintering heating rate. The phase and morphology of the synthesized ceramics were investigated in detail using X-ray diffraction, scanning electron microcopy and energy-dispersive X-ray spectroscopy. It was observed that the grains of these bulk Pr-doped SrTiO3 ceramics were enhanced with Pr-rich grain boundaries. Electronic and thermal transport properties were also investigated as a function of temperature and doping concentration. Such a microstructure was found to give rise to improved thermoelectric properties. Specifically, it resulted in a significant improvement in carrier mobility and the thermoelectric power factor. Simultaneously, it also led to a marked reduction in the thermal conductivity. As a result, a significant improvement (> 30%) in the thermoelectric figure of merit was achieved for the whole temperature range over all previously reported maximum values for SrTiO3-based ceramics. This synthesis demonstrates the steps for the preparation of bulk polycrystalline ceramics of non-uniformly Pr-doped SrTiO3.

Synthesis of Non-uniformly Pr-doped SrTiO3 Ceramics and Their Thermoelectric Properties

A protocol for the synthesis and processing of polycrystalline SrTiO3 ceramics doped non-uniformly with Pr is presented along with the investigation of their thermoelectric properties.

非均匀掺Pr的SrTiO的合成<sub&gt; 3</sub&gt;陶瓷及其热电性能

We demonstrate a novel synthesis strategy for the preparation of Pr-doped SrTiO3 ceramics via a combination of solid state reaction and spark plasma ...

A Simple Method for the Size Controlled Synthesis of Stable Oligomeric Clusters of Gold Nanoparticles under Ambient Conditions

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like oligomeric clusters of these yellow nanoparticles of narrow size distribution are synthesized under ambient conditions via two methods. The delay-time method controls the number of subunits in the oligoclusters by varying the time between the addition of HAuCl4 to alkaline solution and the subsequent addition of reducing agent, NaSCN. The yellow oligoclusters produced range in size from ~3 to ~25 nm. This size range can be further extended by an add-on method utilizing hydroxylated gold chloride (Na+[Au(OH4-x)Clx]-) to auto-catalytically increase the number of subunits in the as-synthesized oligocluster nanoparticles, providing a total range of 3 nm to 70 nm. The crude oligocluster preparations display narrow size distributions and do not require further fractionation for most purposes. The oligoclusters formed can be concentrated &#62;300 fold without aggregation and the crude reaction mixtures remain stable for weeks without further processing. Because these oligomeric clusters can be concentrated before derivatization they allow expensive derivatizing agents to be used economically. In addition, we present two models by which predictions of particle size can be made with great accuracy.

We describe a simple method for producing highly stable oligomeric clusters of gold nanoparticles via the reduction of chloroauric acid (HAuCl4) with sodium thiocyanate (NaSCN). The oligoclusters have a narrow size distribution and can be produced with a wide range of sizes and surface coats.

根据环境条件的金纳米粒子的稳定低聚簇的大小控制合成的一种简便方法

Reducing dilute aqueous HAuCl4 with sodium thiocyanate (NaSCN) under alkaline conditions produces 2 to 3 nm diameter nanoparticles. Stable grape-like ...

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

This protocol details the important steps required for the bioconjugation of a cysteine containing protein to a maleimide, including reagent purification, reaction conditions, bioconjugate purification and bioconjugate characterization.

蛋白质生物缀合物的合成<em&gt;通过</em&gt;半胱氨酸马来酰亚胺化学

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single molecule level. An electrostatic self-assembly and covalent fixation (ESA-CF) process is used for the synthesis of the cyclic poly(tetrahydrofuran) (poly(THF)). The diffusive motion of individual cyclic polymer chains in a melt state is visualized using single molecule fluorescence imaging by incorporating a fluorophore unit in the cyclic chains. The diffusive motion of the chains is quantitatively characterized by means of a combination of mean-squared displacement (MSD) analysis and a cumulative distribution function (CDF) analysis. The cyclic polymer exhibits multiple-mode diffusion which is distinct from its linear counterpart. The results demonstrate that the diffusional heterogeneity of polymers that is often hidden behind ensemble averaging can be revealed by the efficient synthesis of the cyclic polymers using the ESA-CF process and the quantitative analysis of the diffusive motion at the single molecule level using the MSD and CDF analyses.

A protocol for the synthesis and characterization of diffusive motion of cyclic polymers at the single molecule level is presented.

环状聚合物的合成及其在熔融状态扩散运动的表征在单分子水平

We demonstrate a method for the synthesis of cyclic polymers and a protocol for characterizing their diffusive motion in a melt state at the single ...

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of Phosphorus(I)

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable low-valent-phosphorus-containing compound acts as a useful P+ transfer agent. Unlike traditional methods employed to access low-coordinate phosphorus species which usually require pyrophoric phosphorus-containing precursors (white phosphorus, Tris(trimethylsilyl)phosphine, etc.), or harsh reducing agents (alkali metals, potassium graphite, etc.), the current approach does not involve pyrophoric or explosive reagents and can be done on large scales (&#62;20 g) in excellent yields by undergraduates with basic air-free synthetic training. The bromide counter ion is readily exchanged with other anions such as tetraphenyl borate (described herein) using typical salt metathesis reagents to obtain materials with desired properties and reactivities. The versatility of this P+ transfer approach is exemplified by the reactions of these triphosphenium precursors with an N-heterocyclic carbene and an anionic bisphosphine, each of which readily displace the neutral bisphosphine to give an NHC-stabilized phosphorus(I) cation and a phosphorus(I) containing zwitterion, respectively.

Preparation and Reactivity of a Triphosphenium Bromide Salt: A Convenient and Stable Source of PhosphorusI

The synthesis of a triphosphenium bromide salt is described and its use as a P+ transfer agent is outlined by reactions with an N-heterocyclic carbene and an anionic bisphosphine, yielding an NHC-stabilized P(I) cation and a P(I) containing zwitterion, respectively.

制备及反应性的Triphosphenium溴化物盐:磷方便稳定来源（I）

We present herein the optimized synthesis of a triphosphenium bromide salt. Apart from being a versatile metathesis reagent, this unusually stable ...

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, allowing for the synthesis of isotactic poly(&#945;-hydroxy acids) with expected molecular weights (&#62;140 kDa) and narrow molecular weight distributions (Mw/Mn &#60; 1.1). This ring-opening polymerization is mediated by Ni and Zn complexes in the presence of an alcohol initiator and a photoredox Ir catalyst, irradiated by a blue LED (400 - 500 nm). The polymerization is performed at a low temperature (-15 &#176;C) to avoid undesired side reactions. The complete monomer consumption can be achieved within 4 - 8 hours, providing a polymer close to the expected molecular weight with narrow molecular weight distribution. The resulted number-average molecular weight shows a linear correlation with the degree of polymerization up to 1000. The homodecoupling 1H NMR study confirms that the obtained polymer is isotactic without epimerization. This polymerization reported herein offers a strategy for achieving rapid, controlled O-carboxyanhydrides polymerization to prepare stereoregular poly(&#945;-hydroxy acids) and its copolymers bearing various functional side-chain groups.

Controlled Photoredox Ring-Opening Polymerization of O-Carboxyanhydrides Mediated by Ni/Zn Complexes

A protocol for the controlled photoredox ring-opening polymerization of O-carboxyanhydrides mediated by Ni/Zn complexes is presented.

镍/锌配合物介导的O-Carboxyanhydrides 的控制 Photoredox 环开聚合

Here, we describe an effective protocol that combines photoredox Ni/Ir catalysis with the use of a Zn-alkoxide for efficient ring-opening polymerization, ...

Photogeneration of N-Heterocyclic Carbenes: Application in Photoinduced Ring-Opening Metathesis Polymerization

We report a method to generate the N-heterocyclic carbene (NHC) 1,3-dimesitylimidazol-2-ylidene (IMes) under UV-irradiation at 365 nm to characterize IMes and determine the corresponding photochemical mechanism. Then, we describe a protocol to perform ring-opening metathesis polymerization (ROMP) in solution and in miniemulsion using this NHC-photogenerating system. To photogenerate IMes, a system comprising 2-isopropylthioxanthone (ITX) as the sensitizer and 1,3-dimesitylimidazolium tetraphenylborate (IMesH+BPh4-) as the protected form of NHC is employed. IMesH+BPh4- can be obtained in a single step by anion exchange between 1,3-dimesitylimidazolium chloride and sodium tetraphenylborate. A real-time steady-state photolysis setup is described, which hints that the photochemical reaction proceeds in two consecutive steps: 1) ITX triplet is photo-reduced by the borate anion and 2) subsequent proton transfer takes place from the imidazolium cation to produce the expected NHC IMes. Two separate characterization protocols are implemented. Firstly, CS2 is added to the reaction media to evidence the photogeneration of NHC through formation of the IMes-CS2 adduct. Secondly, the amount of NHC released in situ is quantified using acid-base titration. The use of this NHC photo-generating system for the ROMP of norbornene is also discussed. In solution, a photopolymerization experiment is conducted by mixing ITX, IMesH+BPh4-, [RuCl2(p-cymene)]2 and norbornene in CH2Cl2, then irradiating the solution in a UV reactor. In a dispersed medium, a monomer miniemulsion is first formed then irradiated inside an annular reactor to produce a stable poly(norbornene) latex.

We describe a protocol to photogenerate N-heterocyclic carbenes (NHCs) by UV irradiation of a 2-isopropylthioxanthone/imidazolium tetraphenylborate salt system. Methods to characterize the photoreleased NHC and elucidate the photochemical mechanism are proposed. The protocols for ring-opening metathesis photopolymerization in solution and miniemulsion illustrate the potential of this 2-component NHC photogenerating system.

n-杂环卡本的光生成在光致环开环转移聚合中的应用

We report a method to generate the N-heterocyclic carbene (NHC) 1,3-dimesitylimidazol-2-ylidene (IMes) under UV-irradiation at 365 nm to characterize IMes ...

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.

37p20 (o2cr)51聚类中的合成及其转化为 inp 量子点

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 ...

Synthesis of Information-bearing Peptoids and their Sequence-directed Dynamic Covalent Self-assembly

This protocol presents the use of Lewis acidic multi-role reagents to circumvent kinetic trapping observed during the self-assembly of information-encoded oligomeric strands mediated by paired dynamic covalent interactions in a manner mimicking the thermal cycling commonly employed for the self-assembly of complementary nucleic acid sequences. Primary amine monomers bearing aldehyde and amine pendant moieties are functionalized with orthogonal protecting groups for use as dynamic covalent reactant pairs. Using a modified automated peptide synthesizer, the primary amine monomers are encoded into oligo(peptoid) strands through solid-phase submonomer synthesis. Upon purification by high-performance liquid chromatography (HPLC) and characterization by electrospray ionization mass spectrometry (ESI-MS), sequence-specific oligomers are subjected to high-loading of a Lewis acidic rare-earth metal triflate which both deprotects the aldehyde moieties and affects the reactant pair equilibrium such that strands completely dissociate. Subsequently, a fraction of the Lewis acid is extracted, enabling annealing of complementary sequence-specific strands to form information-encoded molecular ladders characterized by matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS). The simple procedure outlined in this report circumvents kinetic traps commonly experienced in the field of dynamic covalent assembly and serves as a platform for the future design of robust, complex architectures.

A protocol is presented for the synthesis of information-encoded peptoid oligomers and for the sequence-directed self-assembly of these peptoids into molecular ladders using amines and aldehydes as dynamic covalent reactant pairs and Lewis acidic rare-earth metal triflates as multi-role reagents.

信息承载Peptoids及其序列定向动态共价自组装的合成

This protocol presents the use of Lewis acidic multi-role reagents to circumvent kinetic trapping observed during the self-assembly of information-encoded ...

稳定笼 Aziridinium 离子的制备及其开环 Azaheterocycles 的合成

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