Catalytic asymmetric conjugate boration of α,β-unsaturated sulfones
作者:Abraham L. Moure、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1039/c1cc11949d
日期:——
The alpha,beta-unsaturated sulfones are suitable activatedolefins in catalytic asymmetric conjugate beta-boration. These substrates undergo smooth conjugate addition of bis(pinacolato)diboron [B(2)(pin)(2)] catalyzed by nonracemic Cu(I)-diphosphine complexes to provide, upon subsequent oxidation, beta-hydroxy sulfones in good yields and high enantiocontrol.
Alkylations of dianions of β-hydroxysulfoxides and β-hydroxysulfones have been found to be affected by chelation of a Li cation with a sulfinyl group and by coordination of the cation with tetrahydrofuran rather than a sulfonyl group, respectively.