contiguous three stereocenters has been a long-standing challenging task in organic synthesis. Herein we present a phoshine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of γ-substitutedallenoates with β-perfluoroalkyl enones, delivering a wide range of densely functionalized perfluoroalkylated cyclopentenes with three contiguous chiral stereocenters.
An efficient organocatalyzedenantioselective conjugated addition of sodium bisulfite to β-trifluoromethyl-α,β-unsaturated ketones using a cinchona alkaloid-derived squaramidecatalyst is presented. A series of optically active sulfonic acids, bearing a tertiary stereocenter connecting a CF3 group and a SO3H group, were obtained in excellent yields with high enantioselectivities (up to 99% yield and
Organocatalytic enantioselective sulfa-Michael addition of thiocarboxylic acids to β-trifluoromethyl-α,β-unsaturated ketones for the construction of stereogenic carbon center bearing a sulfur atom and a trifluoromethyl group
organocatalyzed asymmetric sulfa-Michael addition of thiocarboxylic acids to β-trifluoromethyl-α,β-unsaturated ketones with a chiral bifunctional amine-squaramide as the catalyst is presented. A wide range of chiral ketone compounds bearing a sulfur atom and a trifluoromethyl group at the stereogenic carbon center could be obtained with excellent results (up to 99% yield, 97% ee) under mild conditions. The developed
An efficient double catalytic system, combining chiral amine and 2-mercaptobenzoic acid, is applied for α′,β-regioselective [4+2] annulations of 2-cyclopentenone with a diversity of activated alkenes, constructing multifunctional chiral bicycle[2,2,1]heptane scaffolds in good to excellent yields and enantioselectivities. In comparison with the traditional cross-dienamine species between 2-cyclopentenone
Rh(III)-Catalyzed Diastereodivergent Spiroannulation of Cyclic Imines with Activated Alkenes
作者:Bingxian Liu、Panjie Hu、Ying Zhang、Yunyun Li、Dachang Bai、Xingwei Li
DOI:10.1021/acs.orglett.7b02678
日期:2017.10.6
Rh(III)-catalyzed [3 + 2] annulation of cyclic N-sulfonyl or N-acyl ketimines with activated alkenes has been realized, leading to the synthesis of spirocycles with three continuous stereogenic centers. This atom-economic reaction proceeded efficiently under mild and redox-neutral conditions via a C–H activation pathway, and the coupling is diastereodivergent, with the diastereoselectivity being controlled