Pd(II)—dppb and syngas catalyze regioselective hydroesterification of terminal alkynes under neutral conditions
作者:Bassam El Ali、Jimoh Tijani、Abdel Moneim El-Ghanam
DOI:10.1016/s0040-4039(01)00152-6
日期:2001.3
Palladium(II) regioselectively catalyzes the hydroesterification of terminalalkynesunder syngas forming α,β-unsaturated esters 3 and 4 in excellent chemical yields under neutral conditions. The high selectivity for the linear ester 4 was obtained with a catalytic system that includes Pd(II), 1,4-bis(diphenylphosphino)butane (dppb) and CO/H2 in CH2Cl2 as solvent. The control of the regioselectivity
在中性条件下,钯(II)在合成气中区域选择性地催化末端炔烃的加氢酯化反应,形成出色的化学收率的α,β-不饱和酯3和4。通过在包括CH 2 Cl 2的溶剂中包含Pd(II),1,4-双(二苯基膦基)丁烷(dppb)和CO / H 2的催化体系获得对线性酯4的高选择性。区域选择性的控制在很大程度上取决于配体的类型,溶剂和合成气混合物的使用。
Nonaqueous Ionic Liquids: Superior Reaction Media for the Catalytic Heck-Vinylation of Chloroarenes
tetraphenylphosphonium chloride. The scope of the new reaction medium is outlined for the first time for the vinylation of various aryl halides using different mono- and disubstituted olefins as well as a variety of known palladium(0) and palladium(II) catalyst systems. Furthermore, a novel means of catalyst recycling is presented and its scope is evaluated.
Pd-Catalyzed Threefold Arylation of Baylis-Hillman Bromides and Acetates with Triarylbismuth Reagents
作者:Maddali L. N. Rao、Somnath Giri
DOI:10.1002/ejoc.201200543
日期:2012.8
alkyl 2-benzylacrylates and 2-benzylacrylonitriles were synthesized by means of atom-economic cross-couplings of Baylis–Hillmanbromides or acetates with BiAr3 under palladium-catalyzed conditions. These reactions, involving threefold aryl couplings using BiAr3 reagents with bromides and acetates, are fast and are completed in 1–2 h with high product yields.
Heck reactions catalyzed by Pd(0)-PVP nanoparticles under conventional and microwave heating
作者:Daniela de L. Martins、Heiddy M. Alvarez、Lúcia C.S. Aguiar、Octavio A.C. Antunes
DOI:10.1016/j.apcata.2011.09.014
日期:2011.11
Pd(0) nanoparticles stabilized by polyvinylpyrrolidone (Pd-PVP) with a diameter of 3–6 nm in ethanol catalyzedHeck coupling of iodobenzene with different alkenes under microwave heating. Products were obtained in good yields (62–99%) and good selectivity to the E-isomers. Microwave heating proved to be superior to conventional heating, providing products in higher yields and selectivities in short
A catalytic system utilizing a chelate carbene ligand containing bulk tert-butyl groups is described for palladium-catalyzed Heck and Suzuki coupling reactions. The Heck reaction focused on the coupling of different aryl bromides with mono- and 1,1-disubstitutedolefins while the Suzuki reaction involved the coupling of aryl bromides and phenylboronic acid to afford the corresponding biphenyls. The