Stereocontrolled Access to Unsymmetrical 1,1-Diaryl-2-fluoroethenes
摘要:
A simple and effective method for stereocontrolled preparation of 1,1-diaryl-2-fluoroethenes is reported. First, 1-aryl-1-bromo-2-fluoroethenes are generated using an addition/elimination reaction of hydride to silylated beta,beta-difluorostyrene derivatives followed by a bromination/desilicobromination reaction. Subsequent Suzuki-Miyaura coupling with a variety of boronic acids gives access to the desired 1,1-diaryl-2-fluoroethenes.
An addition/elimination reaction of organolithium reagents to silylated beta,beta-difluorostyrene derivatives followed by a bromination/desilicobromination reaction provides a simple and effective synthetic approach to a wide range of bromofluoroalkenes (up to >97/3). In addition, the bromofluoroalkenes can be used in Pd-catalyzed transformations giving access to both tri- and tetrasubstituted fluoroalkenes.