Rhodium(I)- or ruthenium(II)-catalyzed direct coupling of vinyl ketones with aldehydes and the subsequent reduction to give aldol derivatives anti-selectively
作者:Susumu Sato、Isamu Matsuda、Masahiro Shibata
DOI:10.1016/0022-328x(89)80096-8
日期:1989.11
A vinyl ketone reacts with an aldehyde to give an α-methylene-β-hydroxyalkanone with the concomitant formation of the vinyl ketone dimer in the presence of catalytic amount of RhH(PPh3)4 or RuH2(PPh3)4 under almost neutral conditions. The selectivity of the cross-coupling product is remarkably improved in the presence of an extra mole of aldehyde. This type of cross-coupling is explained by the intermediacy
Alpha-Hydrogen Substituted Nitroxyls And Derivatives Thereof As Catalysts
申请人:Technion Research and Development Foundation Ltd.
公开号:US20140350258A1
公开(公告)日:2014-11-27
Novel alpha-hydrogen substituted nitroxyl compounds and their corresponding oxidized (oxoammonium cations) and reduced (hydroxylamine) forms, and the use of such compounds, inter alia, for oxidation of primary and secondary alcohols to aldehydes and ketones, respectively; resolution of racemic alcohols; desymmetrization of meso-alcohol; as radicals and spin trapping reagents; and as polymerization agents. Processes for preparing the novel nitroxyl/oxoammonium/hydroxylamine compounds from the corresponding amines, and certain novel amine derivatives and their uses. The compounds and amine precursors are useful as ligands for transition metals and as organocatalysts in e.g., aldol reactions.