The palladium-tributylammonium formate reagent in the stereoselective hydrogenation, and stereo- and regioselective hydroarylation of alkyl 4-hydroxy-2-alkynoates: a route to substituted butenolides
The reaction of aryl iodides with alkyl 4-hydroxy-2-alkynoates in the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst provides a convenient route to functionalized substituted butenolides through a one pot hydroarylation/cyclization reaction. In the presence of formic acid, tri-n-butylamine and a palladium(II) catalyst, alkyl 4-hydroxy-2-alkynoates undergo a one pot hydrogenation/cyclization
Metal-Free Reductive Cleavage of C−O σ-bonds in Acyloin Derivatives by an Organic Neutral Super-Electron-Donor
作者:Sylvain P. Y. Cutulic、Neil J. Findlay、Sheng-Ze Zhou、Ewan J. T. Chrystal、John A. Murphy
DOI:10.1021/jo901815t
日期:2009.11.20
Neutral organic electron-donor 7, formally a pyridinylidene carbene dimer, effects reductivecleavage of C−O σ-bonds in acyloin derivatives Ar(CO)CRR′OX (X = OAc, OPiv, OBz, OMs) and this represents the first cleavage of C−O σ-bonds by a neutral organic electron-donor. The methodology is applicable to a large array of substrates and the reduced counterparts were isolated in good to excellent yields
Hg/Pt-catalyzed conversion of bromo alkynamines/alkynols to saturated and unsaturated γ-butyrolactams/lactones via intramolecular electrophilic cyclization
Convenient and general Hg(II)/Pt(IV) catalyzed syntheses of γ-butyrolactams and α,β-unsaturated γ-butyrolactones/lactams are described via intramolecular electrophilic cyclizations of bromoalkynes with tosylamino and hydroxyl tethers. The reaction features the use of wet solvents, the exclusion of any base and additive, mild conditions and practical yields. We also synthesised few chiral lactams through
Sequential Rhodium-Catalyzed Stereo- and Regioselective Addition of Organoboron Derivatives to the Alkyl 4-Hydroxy-2-Alkynoates/Lactonizaction Reaction
The sequential rhodium-catalyzed addition/lactonization reaction of organoboron derivatives to alkyl4-hydroxy-2-alkynoates would constitute a novel methodology for the synthesis of 4-aryl/heteroaryl/vinyl-2(5H)-furanones with an excellent control of the regio- and chemoselectivity. The role played by rhodium precatalyst, ligands, reaction medium, and the feature of organoboron derivatives has been