Effect of fluorine on palladium-catalyzed cross-coupling reactions of aryl bromides with trifluoromethyl aryl ketones via difluoroenol silyl or monofluoroenol silyl ethers
作者:Yong Guo、Jean'ne M. Shreeve
DOI:10.1039/b705137a
日期:——
Palladium-catalyzed cross-coupling reactions of alpha-aryl-beta,beta-difluoroenol silyl and alpha-aryl-beta-fluoroenol silyl ethers with aryl bromides proceed smoothly with good functional compatibility.
Synthesis of optically active gem-difluorinated organic molecules attracts a great deal of interest due to their unique properties in pharmaceutical and agrochemical areas. Herein, a series of enantioenriched α,α-difluoro-β-arylbutanoic esters were prepared in high yields (83–99%) with moderate to excellent enantioselectivities (≤97:3 er) by palladium-catalyzed asymmetrichydrogenation.
Squaramide/Li<sup>+</sup>-Catalyzed Direct S<sub>N</sub>1-Type Reaction of Vinyl Triflates with Difluoroenoxysilanes through Vinyl Cations
作者:Yan Chen、Vincent Gandon、Christophe Bour
DOI:10.1021/acs.orglett.2c02793
日期:2022.9.30
Difluoromethylene-skipped enones have been readily obtained from arylvinyltriflates and aryldifluoroenoxysilanes. While these useful compounds are difficult to synthesize by the classical aldol/dehydration approach, the use of a squaramide/Li+ catalyst allows their direct formation via a vinyl carbocation paired with a weakly coordinating perfluorinated alkoxyaluminate. This strategy makes possible a reaction between