Highly Enantioselective Construction of a Quaternary Carbon Center of Dihydroquinazoline by Asymmetric Mannich Reaction and Chiral Recognition
作者:Biao Jiang、Jia Jia Dong、Yu Gui Si、Xiao Long Zhao、Zuo Gang Huang、Min Xu
DOI:10.1002/adsc.200800039
日期:2008.6.9
The highly enantioselective construction of a quaternary carbon center of dihydroquinazoline by an asymmetric Mannich reaction and chiral recognition are described. The key transformation was to establish the chiral trifluoromethyl quaternary carbon center by a diamine-Brønsted acid-catalyzed enantioselective and regioselective Mannich reaction of a methyl ketone and 4-trifluoromethyldihydroquinazoline
描述了通过不对称曼尼希反应和手性识别对二氢喹唑啉季碳中心的高度对映选择性。关键的转化是通过二胺-布朗斯台德酸催化的甲基酮与4-三氟甲基二氢喹唑啉的对映选择性和区域选择性曼尼希反应建立手性三氟甲基季碳中心。在氢键二聚体中观察到不寻常的对映异构体自歧视现象。仅通过还原六甲基磷酰卤化物(HMPA)中的羰基并消除羟基,即可将有价值的中间体转化为对映体纯净的HIV逆转录酶抑制剂DPC 083(> 99.9 ee)。