gem-(DIFLUOROALLYL)LITHIUM: PREPARATION BY LITHIUM-HALOGEN EXCHANGE AND UTILIZATION IN ORGANOSILICON AND ORGANIC SYNTHESIS.

Article abstract of DOI:10.1021/ja00352a019

gem-(Difluoroallyl)lithium may be generated by lithium-bromine exchange between n-butyllithium and CH//2 equals CHCF//2Br at minus 95 degree C by using an in situ procedure. When this preparation is carried out in the presence of chlorosilanes, aldehydes, ketones, and esters, products are formed, often in good yield. The factors determining the regioselectivity in addition to C equals O of unsymmetrically substituted allylic lithium reagents are discussed.