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.
Sulfone Group as a Versatile and Removable Directing Group for Asymmetric Transfer Hydrogenation of Ketones
作者:Vijyesh K. Vyas、Guy J. Clarkson、Martin Wills
DOI:10.1002/anie.202004658
日期:2020.8.17
The sulfone functional group has a strong capacity to direct the asymmetrictransferhydrogenation (ATH) of ketones in the presence of [(arene)Ru(TsDPEN)H] complexes by adopting a position distal to the η6‐arene ring. This preference provides a means for the prediction of the sense of asymmetric reduction. The sulfone group also facilitates the formation of a range of reduction substrates, and its
A new ruthenium-promoted hydrogenation of β-keto sulfones using MeO-BIPHEP as ligand is reported with complete conversions and enantiomeric excesses over 95%.
A series of beta-hydroxy sulfones were synthesized with high enantioselectivities via a new enantioselective ruthenium-catalyzed hydrogenation using MeO-BIPHEP as a ligand. Some beta-hydroxy sulfones were used in the synthesis of optically active butenolides and gamma-butyrolactones with high yields and enantioselectivities over 95%. (C) 1999 Elsevier Science Ltd. All rights reserved.
Enantioselective reduction of β-keto sulfones using the NaBH4/Me3SiCl system catalyzed by polymer-supported chiral sulfonamide
In the presence of 25 mol% of polymer-supported chiral sulfonamide, a variety of beta-keto sulfones can be reduced into the corresponding beta-hydroxy sulfones in excellent yields and with high enantioselectivities using the reducing system of NaBH4/Me3SiCl. (C) 2002 Elsevier Science Ltd. All rights reserved.