Rhodium-Catalyzed Asymmetric Arylation/Defluorination of 1-(Trifluoromethyl)alkenes Forming Enantioenriched 1,1-Difluoroalkenes
摘要:
The reaction of 1-(trifluoromethyl)alkenes (CF3CH=CHR) with arylboroxines (ArBO)(3) in the presence of a chiral diene-rhodium catalyst gave high yields of chiral 1,1-difluoroalkenes (CF2=CHC*HArR) with high enantioselectivity (>= 95% ee). The reaction is assumed to proceed through beta-fluoride elimination of a beta,beta,beta-trifluoroalkylrhodium intermediate that is generated by arylrhodation of the 1-(trifluoromethyl)alkene.
Ligand-Enabled Copper-Catalyzed Regio- and Stereoselective Allylboration of 1-Trifluoromethylalkenes
作者:Yuki Kojima、Yuji Nishii、Koji Hirano
DOI:10.1021/acs.orglett.2c03024
日期:2022.10.14
A copper-catalyzed regio- and stereoselectiveallylboration of 1-trifluoromethylalkenes with bis(pinacolato)diboron (pinB–Bpin) and allylic chlorides has been developed to form functionalized trifluoromethylated products with high diastereoselectivity. The key to success is the judicious choice of Cs2CO3 base and t-Bu-modified dppe-type ligand, which enables the otherwise challenging high catalyst