Bis(imidazolium) chlorides based on 1,2-phenylenediamine were introduced as efficientligand precursors in the Pd-catalyzed Mizoroki-Heck cross-coupling reactions of substituted aryl halides with activated alkenes to afford the corresponding functionalized alkenes. While high to excellent yields (78–96%) were obtained with aryl bromides, moderate yields (51–59%) were achieved for aryl chlorides in
A Robust First-Pass Protocol for the Heck–Mizoroki Reaction
作者:Paul M. Murray、John F. Bower、David K. Cox、Ewan K. Galbraith、Jeremy S. Parker、Joseph B. Sweeney
DOI:10.1021/op300364p
日期:2013.3.15
The Heck-Mizoroki (HM) reaction is one of the most widely used C-C bond-forming methods of contemporary synthesis. Notwithstanding this, these reactions frequently require significant optimization before efficient transformations can be obtained. We describe here the results of a study that aimed to establish a generic experimental protocol for HM reactions which enables acceptable yields from first-pass experiments. The methodology utilizes readily available stable catalysts and can be applied to a broad range of coupling partners.
A Phosphane‐Free Catalyst System for the Heck Arylation of Disubstituted Alkenes: Application to the Synthesis of Trisubstituted Olefins
A new general procedure for the Heck arylation of disubstituted olefins is described. This procedure allows, in many instances, the stereoselective synthesis of trisubstituted olefins. Trisubstituted olefins are easily accessible under mild reaction conditions using a new catalyst system consisting of dicyclohexylamine or methyl-(dicyclohexyl)amine and a phase-transfer catalyst. The choice of base was found to be crucial for the rate and stereoselectivity of the Heck arylation reactions. This method is applicable to the coupling of both electron-deficient and electron-rich aryl halides and displays good stereoselectivity and a high degree: of functional group compatibility. Labeling studies indicate that the source of this selectivity is thermodynamic in nature.
PHENYLALKYL SULFAMATE COMPOUND AND MUSCLE RELAXANT COMPOSITION COMPRISING THE SAME