N,N-dichloro-2-nitrobenzenesulfonamide as the electrophilic nitrogen source for direct diamination of enones.
N,N-dichloro-2-nitrobenzenesulfonamide as the electrophilic nitrogen source for direct diamination of enones.
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DOI：
10.1021/jo030193j
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发表时间：
2003-10
期刊：
影响因子：
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通讯作者：
Wei Pei;Han-Xun Wei;Dianjun Chen;A. Headley;Guigen Li
中科院分区：
文献类型：
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作者：
Wei Pei;Han-Xun Wei;Dianjun Chen;A. Headley;Guigen Li
N，N-二氯邻硝基苯磺酰胺（2-NsNCl_2）是一种有效的亲电氮源，可用于α，β-不饱和酮的直接二胺化反应，而无需使用任何金属催化剂。该反应非常方便，无需惰性气体保护即可进行。发现分子筛（4 A）和温度在控制3-三氯甲基和二氯甲基咪唑啉产物的形成中起关键作用（16个实施例）。所得二胺产物的2-Ns-保护基可以在温和的Fukuyama条件下容易地裂解。提出了[2+3]环化和N-氯化反应的新机理假说，对产物的结构，特别是区域和立体化学进行了解释。
N,N-dichloro-o-nitrobenzenesulfonamide (2-NsNCl2) was found to be an effective electrophilic nitrogen source for the direct diamination of alpha,beta-unsaturated ketones without the use of any metal catalysts. The reaction is very convenient to carry out without the protection of inert gases. Molecular sieves (4 A) and temperature were found to play key roles in controlling the formations of 3-trichloromethyl and dichloromethyl imidazoline products (16 examples). The 2-Ns-protection group of the resulting diamine products can be easily cleaved under mild Fukuyama's conditions. A new mechanism hypothesis of [2+3] cyclization and N-chlorination has been proposed to explain the product structures, particularly their regio- and stereochemistry.