一种由全氟碘代烷合成全氟羧酸的新方法

A New Method for the Synthesis of Perfluorocarboxylic Acids from Perfluoroalkyl Iodides

全氟羧酸是一类用途极广的含氟化合物,其主要工业合成方法有电化学氟化和全氟碘代烷的强氧化性、强酸性水解。为了避免前一方法收率低,副反应多,而后一方法反应条件苛刻等不利因素,近年来人们对在温和条件下合成全氟羧酸愈来愈感兴趣。由于R_F基因的强烈吸电子作用,以及氟原子的屏蔽效应,全氟碘代烷及全氟溴代烷易与电子供体通过受体一供体的相互作用形成加合物。如:

Irradiation of perfluoroalkyl iodides (R_()CF_2I) with UV in the presence of Et_3N and O_2 afforded a simple and effective synthesis of porfluorocarboxylic acids (R_()CO_2H) in good yields. The conditions used wore mild and no hydrogen abstraction product (R_()CF_2H) was formed. The mechanism of such photooxidation was briefly discussed.