Gold(I)-Catalyzed Asymmetric Synthesis of Planar Chiral Arene Chromium Complexes

Gold(I)-catalyzed asymmetric cyclization of 1,3-dihydroxymethyl-2-alkynylbenzene chromium complexes gave planar chiral isochromene chromium complexes with high enantioselectivity. Enantiomeric excess of the cyclization products was largely affected by a combination of axially chiral diphosphine(AuCl)(2) precatalysts and silver salts. A system of segphos(AuCl)(2) with AgBF4 resulted in the formation of the corresponding antipode.