A diarylprolinol in an asymmetric, catalytic, and direct crossed-aldol reaction of acetaldehyde
A diarylprolinol in an asymmetric, catalytic, and direct crossed-aldol reaction of acetaldehyde
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DOI：
10.1002/anie.200704870
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发表时间：
2008-01-01
影响因子：
16.6
通讯作者：
Ishikawa, Hayato
中科院分区：
文献类型：
--
作者：
Hayashi, Yujiro;Itoh, Takahiko;Ishikawa, Hayato
无过度反应：发现二芳基脯氨醇是乙醛的直接、对映选择性羟醛缩合反应的有效有机催化剂，以良好的产率和优异的对映选择性提供β-羟基α-未取代的醛（参见方案）。在所提出的过渡态中，由于醛与有机催化剂的OH基团之间的氢键，醛在中间体烯胺的更受阻的面上反应。
(Chemical Equation Presented) No over-reacting: A diarylprolinol was found to be an effective organocatalyst of the direct, enantioselective aldol reaction of acetaldehyde, affording β-hydroxy α-unsubstituted aldehydes in good yield with excellent enantioselectivity (see scheme). In the proposed transition state the aldehyde reacts on the more hindered face of the intermediate enamine as a consequence of the hydrogen bond between the aldehyde and the OH group of the organocatalyst.