RESUMEN
Herein, we designed a reaction for the desymmetrization-addition of cyclopropenes to imines by leveraging the synergy between photoredox and asymmetric cobalt catalysis. This protocol facilitated the synthesis of a series of chiral functionalized cyclopropanes with high yield, enantioselectivity, and diastereoselectivity (44 examples, up to 93% yield and >99% ee). A possible reaction mechanism involving cyclopropene desymmetrization by Co-H species and imine addition by Co-alkyl species was proposed. This study provides a novel route to important chiral cyclopropanes and extends the frontier of asymmetric metallaphotoredox catalysis.
RESUMEN
A visible-light-induced synthesis protocol for silylmonofluoroalkanes is described. The silylation of alkenyl fluorides using (trimethylsilyl)silanes as organosilicon reagents proceeds well under mild conditions via a sequential photoinduced single-electron transfer and protonation process. The protocol shows a broad substrate scope, transition-metal-free conditions, and high functional group tolerance. A wide variety of silylmonofluoroalkanes were obtained in generally good yields (up to 82%).