已经开发了利用多个亲核性芳族取代和周环反应的抗癌黄酮天然产物termicalcicolanone A的全合成。吡喃并[3,2 - b ]黄嘌呤-6-骨架是通过NHC催化的芳基化反应生成的二苯甲酮中间体,经克莱森环化形成吡喃环,并通过分子内的1,4-加成反应构建an吨酮骨架。通过区域选择性克莱森重排在合成的最后阶段引入异戊二烯基。合成已通过19个步骤完成。
Palladium-Catalyzed Regio-, Diastereo-, and Enantioselective Benzylic Allylation of 2-Substituted Pyridines
作者:Barry M. Trost、David A. Thaisrivongs
DOI:10.1021/ja904441a
日期:2009.9.2
We report a new method for the highly regio-, diastereo-, and enantioselective palladium-catalyzed allylic alkylation of 2-substituted pyridines that allows for the formation of homoallylic stereocenters containing alkyl, aryl, heteroaryl, and nitrogen substituents. When the reaction is conducted with asymmetric acyclic electrophiles, both linear and branched products may be obtained exclusively by