Diastereo- and Enantioselective Catalytic Vinylogous Mukaiyama-Mannich Reactions of Pyrrole-Based Silyl Dienolates with Alkyl-Substituted Aldehydes

A reliable, catalytic asymmetric vinylogous Mukaiyama−Mannich reaction of pyrrole-based silyl dienolates is introduced that is particularly apt for alkyl- and α-alkoxyalkyl-substituted aldehydes. The reaction course is effectively orchestrated by the Hoveyda−Snapper amino acid-based chiral ligand/silver(I) catalyst combination to produce valuable vicinal diamino carbonyl compounds in high yields, with virtually complete γ-site- and anti-selectivity and significant catalyst-to-product chirality transfer. The utility of the Mannich products can be seen in the synthesis of an unprecedented perhydrofuro[3,2-b]pyrrolone product, an aza-analogue of naturally occurring (+)-goniofufurone.