Catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes to versatile enantioenriched-fluoroalkyl amines.
Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive radical species. Here we report a catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical sources, providing a versatile platform to access four types of enantioenriched α-tertiary pyrrolidines bearing β-perfluorobutanyl, trifluoromethyl, difluoroacetyl and even difluoromethyl groups in excellent yields and with excellent enantioselectivity. The key to success is not only the introduction of the CuBr/chiral phosphoric acid dual-catalytic system but also the use of silver carbonate to suppress strong background and side hydroamination reactions caused by a stoichiometric amount of the in situ generated HCl. Broad substrate scope, excellent functional group tolerance and versatile functionalization of the products make this approach very practical and attractive.
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Jin-Shun
JS
Lin
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Fu-Li
FL
Wang
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Xiao-Yang
XY
Dong
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Wei-Wei
WW
He
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Yue
Y
Yuan
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Su
S
Chen
Department of Chemistry, South University of Science and Technology of China, Shenzhen 518055, China.
Xin-Yuan
XY
Liu