Taming of Furfurylidenes by Chiral Bismuth‐Rhodium Paddlewheel Catalysts. Preparation and Functionalization of Optically Active 1,1‐Disubstituted (Trifluoromethyl)cyclopropanes

Abstract

Although 2‐furyl‐carbenes (furfurylidenes) are prone to instantaneous electrocyclic ring opening, chiral [BiRh]‐paddlewheel complexes empowered by London dispersion allow (trifluoromethyl)furfurylidene metal complexes to be generated from a bench‐stable triftosylhydrazone precursor. These reactive intermediates engage in asymmetric [2+1] cycloadditions and hence open entry into valuable trifluoromethylated cyclopropane or ‐cyclopropene derivatives in optically active form, which are important building blocks for medicinal chemistry but difficult to make otherwise.