A Stereospecific Entry to Functionalized cis-1,2-Difluoroalkenes

摘要

The stereospecific preparation of various 1,2-difluoroalkenyl synthons and their utilization for the synthesis of the corresponding functionalized 1,2-difluoroalkenes is discussed. The focus of this review is on the recent developments in our laboratory on the stereospecific introduction of several cis-1,2-difluoroalkenylorganometallic building blocks and their functionalization for the preparation of synthetically intricate cis-1,2-difluoroalkenes, such as cis-1,2-difluorostyrenes, cis-2-iodo-1,2-difluorostyrenes, cis-2-alkylsubstituted-1,2-difluoro-styrenes, cis-aryl substituted 2,3-difluoroacrylic esters, cis-2,3-difluoro-4-oxo-substituted 2-butenoates, symmetrically and unsymmetrically substituted cis-1,2-difluorostilbenes, cis-1-arylperfluoroalkenes and cis-1-iodoperfluoroalkenes. The terminology 'cis' or 'trans'-1,2-difluoro refers to fluorines on the same or opposite side of the double bond of the 1,2-difluoroalkenyl species.