Pd-catalyzed [3 + 2] cycloaddition of cyclic ketimines and trimethylenemethanes toward -fused pyrrolidines bearing a quaternary carbon.

A Pd-catalyzed [3 + 2] cycloaddition of -sulfonyl cyclic ketimines and trimethylenemethanes (TMM) was developed that afforded -fused pyrrolidines bearing a quaternary carbon. Under mild reaction conditions, structurally diverse -sulfonyl cyclic imines, including sulfamate-fused aldimines, aryl- or styryl-substituted sulfamate-derived ketimines, and -sulfonyl cyclic ketimines, were tolerated as reactants, affording -fused pyrrolidines with high efficiency.

Co-Catalyzed C-H Alkenylation and Allylation with Cyclopropenes via Sequential C-H/C-C Bond Activation.

An atom-economical strategy for the C-H alkenylation and C-H allylation of arenes by employing cyclopropenes as versatile alkenylating and allylating reagents is reported, catalyzed by cobalt. The Co-catalyzed C-H alkenylation process involves sequential C-H and C-C bond cleavage. Under the optimized conditions, broad-ranging alkenylated (hetero)arenes were synthesized with complete ()-stereoselectivity (up to 91%).