Facile Synthesis of 1,1-Difluoroallenes via the Difluorovinylidenation of Aldehydes and Ketones
作者:Misaki Yokota、Kohei Fuchibe、Mikiko Ueda、Yuka Mayumi、Junji Ichikawa
DOI:10.1021/ol9016673
日期:2009.9.3
2-Bromo-3,3-difluoroallylic acetates were readily prepared by the reaction of carbonyl compounds with 1-bromo-2,2-difluorovinyllithium, generated from 1,1-dibromo-2,2-difluoroethylene, followed by acetylation. On treatment with butyllithium, the bromoacetates underwent selective 1,2-elimination of lithium acetate to afford mono- and disubstituted 1,1-difluoroallenes in high yields.
通过使羰基化合物与由1,1-二溴-2,2-二氟乙烯生成的1-溴-2,2-二氟乙烯基锂反应,然后进行乙酰化,可以容易地制备2-溴-3,3-二氟烯丙基乙酸酯。用丁基锂处理后,溴乙酸盐进行乙酸锂的1,2-消除选择性反应,以高收率得到单-和二取代的1,1-二氟丙二烯。