Rhodium-Catalyzed Asymmetric Cyclizations of γ-Alkynylaldehydes

Significance

The authors report a rhodium(I)-catalyzed asymmetric cyclization of γ-alkynylaldehydes and acyl phosphonates via C-P or C-H bond cleavage with excellent enantioselectivities. Based on ligand choice, both C-H and C-P bond cleavage products can be formed exclusively in fair to good yields and generally outstanding asymmetric induction. The authors propose several mechanistic possibilities, but indicate that further studies are needed in order to elucidate the reaction mechanism.