DBU-catalyzed sequential intermolecular and intramolecular nucleophilic addition reactions between gem-difluoroolefins and o-hydroxy/mercapto benzaldehydes have been developed to provide a [4 + 2] annulation strategy for facile synthesis of gem-difluorinated isoflavanol derivatives. The competitive addition–elimination reaction of gem-difluoroolefins with nucleophiles was avoided under mild conditions,
已经开发了在宝石-二
氟烯烃和邻-羟基/巯基
苯甲醛之间的
DBU催化的连续的分子间和分子内亲核加成反应,以提供[4 + 2]环化策略,以容易地合成宝石-二
氟异黄烷醇衍
生物。在温和的条件下避免了宝石-二
氟烯烃与亲核试剂的竞争性加成-消除反应,从而以优异的产率获得了2,2-二
氟代的4-异黄烷醇或2,2-二
氟代的4-
硫代异黄烷醇。