CuI/RhII-Catalyzed Tandem Convergent Multicomponent Reaction for the Regio- and Stereocontrolled Synthesis of γ-Oxo-β-amino Esters

The first example of a highly regio- and stereo-selective catalytic method for the three-component one-pot synthesis of highly functionalized alpha-vinylated gamma-oxo-beta-amino esters is disclosed. In this catalytic triad, the Cu-I-catalyst selectively catalyzes the, cycloaddition of the 1-alkyne and sulfonyl azide first resulting in the corresponding 1-sulfonyl-1,2,3-triazole. An a-imino Rh-II-carbene is generated from an open-chain alpha-imino diazo of the triazole, and this species reacts with gamma-hydroxy alpha,beta-unsaturated esters to form allylic (Z)-amino vinyl ethers. Rapid deconjugative [3,3]-sigmatropic rearrangement affords the alpha-vinyl gamma-oxo-beta-amino esters in high yields with high levels of diastereoselectivity.