Lipase-promoted dynamic kinetic resolution of racemic β-hydroxyalkyl sulfones
摘要:
A series of racemic beta aryl-hydroxyalkyl sulfones have been successfully transformed into the corresponding optically active O-acetyl derivatives in high yields (up to 80%) with enantiomeric excesses more than 99% using a dynamic kinetic resolution procedure, in which a lipase-promoted kinetic resolution is combined with a concomitant ruthenium-catalysed racemization of the substrates. (c) 2005 Elsevier Ltd. All rights reserved.
Efficient synthesis of optically active β-hydroxy p-tolylsulfones with very high enantiomeric excess via CBS–oxazaborolidine-catalyzed borane reduction
摘要:
A simple, efficient synthesis of optically active beta -hydroxy p-tolylsulfones with > 99% e.e. by employing CBS oxazaboronlidene-catalyzed asymmetric borane reduction of beta -keto p-tolylsulfones using N-ethyl-N-iso-propylaniline-borane complex as the borane carrier has been established. (C) 2001 Elsevier Science Ltd. All rights reserved.
Synthesis of β- and γ-hydroxy sulfones by regioselective opening of β,γ-epoxy sulfones
作者:Carmen Nájera、José Miguel Sansano
DOI:10.1016/s0040-4020(01)90534-4
日期:1990.1
sulfones react regio-selectively with organomagnesium compounds in the presence or not of catalytic amounts of copper(I) bromide to afford β-hydroxy sulfones 2 or γ-tosylated allylic alcoholates 5 respectively. The Michael type addition of Grignard reagents to intermediates 5 in the presence of catalytic amount of copper(l) bromide yields γ-hydroxy sulfones 6. The PCC oxidation of β- and γ-hydroxy sulfones
Polyethylene glycol (PEG) 4000 catalysed regioselective nucleophilic ring opening of oxiranes - A new and convenient synthesis of β-hydroxy sulfone and β-hydroxy sulfide
作者:A.K. Maiti、P. Bhattacharyya
DOI:10.1016/s0040-4020(01)89588-0
日期:1994.1
Oxiranes and sodium p-toluene sulfinate salt react smoothly in a regioselective manner in the presence of PEG4000 to furnish β-hydroxy sulfone and β-hydroxysuifide. The reaction was extended for the preparation of alkylsulfones and β-oxosulfones from alkylhalide and β-oxohalide respectively.