Enantioselective organocatalytic conjugate addition of N heterocycles to α,β-unsaturated aldehydes
Enantioselective organocatalytic conjugate addition of N heterocycles to α,β-unsaturated aldehydes
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DOI：
10.1002/anie.200604854
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发表时间：
2007-01-01
影响因子：
16.6
通讯作者：
Jorgensen, Karl Anker
中科院分区：
文献类型：
--
作者：
Diner, Peter;Nielsen, Martin;Jorgensen, Karl Anker
自从脯氨酸催化的羟醛缩合反应被重新发现以来，有机催化[1]在过去的几年中得到了广泛的发展。[2]从那时起，已经开发了几种不同的方法，例如双甲基化，[3]氯化，[4]溴化，[5]亚磺酰化，[6]胺化，[7]和曼尼希反应[8]，用于具有高立体选择性的醛和酮的α-官能化。这些反应的催化剂主要是手性仲胺和咪唑烷酮，它们通过烯胺机理活化羰基化合物。[9]手性仲胺也是对映选择性β加成到α，β-不饱和羰基化合物的有效催化剂。在这些α，β-不饱和体系的情况下，催化剂通过亚胺离子机制活化底物，从而促进亲核试剂加成到β-碳原子上。该反应方案已被开发用于许多不同的反应，如环加成反应，[10]还原，[11]和迈克尔加成。[12个]
Organocatalysis [1] has expanded widely within the last few years, since the rediscovery of the proline-catalyzed aldol reaction.[2] Since then, several different methods, such as fluorination,[3] chlorination,[4] bromination,[5] sulfenylation,[6] amination,[7] and Mannich reactions,[8] have been developed for the α-functionalization of aldehydes and ketones with high stereoselectivity. The catalysts for these reactions are mainly chiral secondary amines and imidazolidinones, which activate the carbonyl compounds by an enamine mechanism.[9]Chiral secondary amines are also effective catalysts for enantioselective β addition to α, β-unsaturated carbonyl compounds. In the case of these α, β-unsaturated systems, the catalyst activates the substrate through the iminium-ion mechanism, thereby facilitating the addition of the nucleophile to the β-carbon atom. This reaction protocol has been developed organocatalytically for a number of different reactions such as cycloaddition reactions,[10] reductions,[11] and Michael additions.[12]