A highlyenantioselectivesynthesis of tetrahydroindolizines by catalytic multicomponent cycloaddition reactions of diazoacetate, pyridine, and alkenyloxindole was developed. Under the relay catalysis, involving an achiral iron(III) catalyst and chiral N,N′‐dioxide‐scandium(III) complex, a series of tetrahydroindolizines bearing different substituents were obtained in moderate to high yields (up to
Catalytic, enantioselective 1,3-dipolar cycloadditions of nitrile imines with methyleneindolinones
作者:Anthony L. Gerten、Michael C. Slade、Kelsie M. Pugh、Levi M. Stanley
DOI:10.1039/c3ob41815d
日期:——
Catalytic, enantioselective1,3-dipolarcycloadditions of nitrile imines with methyleneindolinones are reported. The spiro[pyrazolin-3,3′-oxindole] products are formed in good yields (up to 98%) and high enantioselectivity (up to 99% ee).
An efficient and highly enantioselective Michael addition of nitroalkanes to 3-ylidene oxindoles is described, mediated by thiourea-basedbifunctionalorganocatalysts. The stereochemistry at Cα and Cβ centers is perfectly controlled, and the intermediate C-3 enolate is trapped with a second Michael acceptor. The developed one-pot three-component consecutive reactions generate up to four contiguous