Dirhodium(II)-catalyzed enantioselective cyclopropenation of internal alkynes with trifluoromethyl carbene

Catalytic enantioselective reactions of trifluoromethyl carbene represent a powerful method for the construction of chiral trifluoro-methyl-functionalized molecules, but the utilization of less reactive internal alkynes remains a persistent challenge in this domain. Here-in, we report a chiral dirhodium(II) complex-catalyzed enantioselec-tive cyclopropenation reaction of disubstituted alkynes by using 2,2,2-trifluorodiazoethane (CF3CHN2) as the trifluoromethyl car-bene precursor. Achiral axial ligation by solvent molecules proves to be a key to improve the reactivity and control the stereoselectiv-ity of metallocarbene species. This transformation provides efficient access to a wide range of enantioenriched trifluoromethyl group -substituted cyclopropenes, cyclopropanes, fused cyclopropane de-rivatives, and cyclopropyl boronate. The presented methodology constitutes a practical solution to a long-standing hurdle in catalytic enantioselective cyclopropenation of trifluoromethyl carbene with internal alkynes.

Automated summary

In this study, a chiral dirhodium(II) complex-catalyzed enantioselective cyclopropenation reaction was reported, which successfully synthesized enantioenriched trifluoromethyl group-substituted cyclopropenes, cyclopropanes, fused cyclopropane derivatives, and cyclopropyl boronate by using 2,2,2-trifluorodiazoethane as the trifluoromethyl carbene precursor. This research provides a practical solution to a long-standing hurdle in catalytic enantioselective cyclopropenation of trifluoromethyl carbene with internal alkynes.