Asymmetric Retro-Claisen Reaction by Chiral Primary Amine Catalysis
作者:Yunbo Zhu、Long Zhang、Sanzhong Luo
DOI:10.1021/jacs.6b00627
日期:2016.3.30
The communication describes an enamine-based asymmetric retro-Claisen reaction of β-diketones by primaryamine catalysis. The reaction proceeds via a sequence of stereoselective C-C formation, C-C cleavage, and a highly stereospecific enamine protonation to afford chiral α-alkylated ketones or macrolides with high yields and enantioselectivities. A detailed mechanism was explored on the basis of experimental
该通讯描述了伯胺催化下 β-二酮的基于烯胺的不对称逆克莱森反应。该反应通过一系列立体选择性 CC 形成、CC 裂解和高度立体有择的烯胺质子化进行,以提供具有高产率和对映选择性的手性 α-烷基化酮或大环内酯。在实验证据和计算研究的基础上探索了详细的机制,以解释观察到的立体控制。
Asymmetric Mannich Reaction of Fluorinated Ketoesters with a Tryptophan-Derived Bifunctional Thiourea Catalyst
作者:Xiao Han、Jacek Kwiatkowski、Feng Xue、Kuo-Wei Huang、Yixin Lu
DOI:10.1002/anie.200903635
日期:2009.9.28
Fluorinated quaternary stereocenters: A novel bifunctionalcatalyst 1 derived from natural tryptophan promoted the Mannichreaction of α‐fluoro‐β‐ketoesters to afford fluorinated chiral molecules containing vicinal quaternary and tertiary stereogenic centers with exceptional enantioselectivity. An unprecedented α‐fluoro‐β‐lactam was also prepared by this method (see scheme; Boc=tert‐butoxycarbonyl)