Chemoselective Conjugate Addition of Dimethylzinc-Mediated Ether and Acetal Radicals to Alkylidenemalonates and Asymmetric Reactions
作者:Ken-ichi Yamada、Masaru Maekawa、Tito Akindele、Mayu Nakano、Yasutomo Yamamoto、Kiyoshi Tomioka
DOI:10.1021/jo801541m
日期:2008.12.19
ether or acetal radicals were generated directly from ethers or acetals by the action of dimethylzinc-air, and their subsequent conjugate addition reaction with alkylidenemalonates afforded the corresponding conjugate adducts in reasonably high yields. The reaction with benzylidenemalonates bearing formyl and imino groups gave chemoselectively the conjugate addition products. The asymmetric reaction of
通过二甲基锌-空气的作用,直接从醚或缩醛中生成环状和无环的醚或缩醛基,随后它们与亚烷基丙二酸酯的共轭加成反应以合理的高收率提供了相应的共轭加合物。与带有甲酰基和亚氨基的亚苄基丙二酸酯的反应产生了化学选择性的结合物加成产物。双(8-苯基薄荷基)亚苄基丙二酸酯的不对称反应非对映选择性地进行,以提供93:7 dr的加合物。