Rh^II/Zn^II Catalyzed Asymmetric [4+3] Cycloaddition Reaction

Bimetallic Catalytic Tandem Reaction of Acyclic Enynones: Enantioselective Access to Tetrahydrobenzofuran Derivatives

“…Unfortunately, a preliminary attempt at asymmetric catalysis with α,β-unsaturated aldehyde afforded only low diastereoselectivity with a moderate ee value. As part of our ongoing interest in cycloaddition reactions and inspired by Zhang’s work, we envisioned that a dual-metal catalyst consisting of gold salt and a chiral metal- N , N ′-dioxide catalyst would be potentially suitable in promoting the in situ generation of furan-based o -QDMs and the successive enantioselective annulation reaction with electron-deficient olefins (Scheme c). Herein we disclose our endeavor along this line.…”

“…On the basis of our previous works , and the X-ray crystal structures of catalyst and products, a possible working mode was proposed to elucidate the stereoselective control of the reaction. As illustrated in Scheme , electron-deficient olefin 2g was activated by bidentate coordination with the L-RaEt 2 Me– Co II complex.…”