Exploring the boundaries of vinylogous Mukaiyama aldol processes: stereoselective access to polyunsaturated homoallylic alcohols

Catalytic enantioselective vinylogous aldol reactions using extended enolates are of prominent value in synthetic organic chemistry. Here, we report our advances in the development of enantioselective bis-vinylogous and hyper-vinylogous Mukaiyama aldol reactions between a series of polyenylsilyloxy furans or polyenylsilyoxy indoles and aromatic aldehydes, realized by use of the enabling catalyst combination of silicon tetrachloride and Denmark’s chiral bis-phosphoramide base (R,R)-I. Several crucial issues such as the remote site-, enantio- and geometrical selectivity of the reaction will be highlighted, ultimately focusing on one main question:how far can we push the limits of the vinylogous reactivity transmittal?