Regioselective nucleophilic addition of 3-aryl-5-difluoromethyl-isoxazoles to aldehydes
作者:Xueyan Yang、Xiang Fang、Dong Zhang、Yanlin Yu、Zhengdong Zhang、Fanhong Wu
DOI:10.1016/j.jfluchem.2012.11.003
日期:2013.1
A series of 5-difluoromethyl-isoxazoles 2 were prepared, and their regioselective nucleophilic addition to aldehydes was investigated. It was found that the nucleophilic difluoromethylation of aldehydes with 5-difluoromethyl-isoxazoles could be efficiently and uniquely achieved in the presence of LDA as a base that provides a large steric hindrance. In contrast, 3,4,5-trisubstituted 5-difluoromethyl
制备了一系列5-二氟甲基-异恶唑2,并研究了它们对醛的区域选择性亲核加成。已经发现,在LDA作为提供大空间位阻的碱的存在下,醛与5-二氟甲基-异恶唑的亲核二氟甲基化可以有效且独特地实现。相反,当使用n- BuLi作为碱时,以适中的收率交替提供3,4,5-三取代的5-二氟甲基异恶唑作为唯一产物。