Catalytic asymmetric intramolecular α-alkylation of aldehydes
Catalytic asymmetric intramolecular α-alkylation of aldehydes
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DOI：
10.1021/ja0392566
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发表时间：
2004-01-21
影响因子：
15
通讯作者：
List, B
中科院分区：
文献类型：
--
作者：
Vignola, N;List, B
发展一种通用的催化不对称醛α-烷基化反应是有机合成中的一大挑战。在这里，我们报道了第一个成功的合成方法： (S)-α-甲基Pro催化各种卤代醛分子内烷基化成相应的甲酰基环戊烷、-环丙烷或-吡咯烷，具有极高的产率和对映体选择性。最值得注意的是，外消旋、缩醛或催化剂烷基化没有发生任何显著的程度，进一步说明了烯胺催化的威力、温和和深刻的选择性。
The development of a general catalytic asymmetric aldehyde α-alkylation reaction constitutes a major challenge in organic synthesis. Here, we report the first and successful approach toward its solution: (S)-α-methyl proline catalyzes the intramolecular alkylation of various halo aldehydes to the corresponding formyl cyclopentanes, -cyclopropanes, or -pyrrolidines in excellent yields and enantioselectivities. Most remarkably, racemization, aldolization, or catalyst alkylation do not occur to any significant extend, further illustrating the power, mildness, and profound selectivity of enamine catalysis.