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
A facile approach to spirocyclic butenolides through cascade cyclization/oxidative cleavage reactions of (Z)-enynols catalyzed by gold under dioxygen atmosphere
作者:Feijie Song、Yuanhong Liu
DOI:10.1016/j.jorganchem.2008.10.046
日期:2009.2
A facile approach for the syntheses of spirocyclic butenolides through cascade cyclization/oxidative cleavage reactions of (Z)-enynols bearing cyclic substituents at the C-1 position catalyzed by gold under dioxygen atmosphere has been developed. A variety of substituted butenolides was constructed in a regioselective manner from suitably substituted (Z)-2-en-4-yn-1-ols. (Z)-Enynols substituted both
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