Asymmetric Au-catalyzed domino cyclization/nucleophile addition reactions of enynes in the presence of water, methanol and electron-rich aromatic derivatives

An efficient Au(I) catalytic system is described for the asymmetric domino cyclization/functionalization reactions of functionalized 1,6-enynes in the presence of an external nucleophile. The use of (R)-4-MeO-3,5-(t-Bu)₂-MeOBIHEP ligand associated with gold led to clean rearrangements implying the formal addition of an oxygen or carbon nucleophile to an alkene followed by a cyclization process. The enantiomeric excesses were highly dependant on the substrate/nucleophile combination. Very good enantiomeric excesses up to 98% were obtained in the case of substrates bearing larger groups (hindered diesters and disulfones) and in the case of hindered carbon nucleophiles.