Organocyanocopper-Trifluoroborane Mediated 1,3-Chirality Transfer Reaction of γ-(Mesyloxy)-α-alkyl α,β-Enoates for the Construction of Chiral Quaternary Carbon Centers with High Optical Purity

Article abstract of DOI:10.1021/jo00278a015

The mesylates of chiral γ-hydroxy-α-methyl (E)-α,β-enoates undergo 1,3-chirality transfer to form chiral α-alkyl-α-methyl (E)-β,γ-enoates with high optical purity using organocyanocopper-trifluoroborane reagents.The degree of asymmetric induction, regiochemistry, and chemoselectivity has been found to be uniformly high.THF or mixed solvents involving THF, a γ-(methylsulfonyl)oxy leaving group, and organocopper-Lewis acid regents prepared from CuCN, RLi, and BF3*Et2O were found to be necessary to ensure the success of the preparation of chiral quaternarycarbon centers with high optical purity via the 1,3-chirality transfer.The present efficient procedure is compatible with a variety of oxygenated groups such as mesyl, benzyl, tert-butyldimethylsilyl, and isopropylidene functions.