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。
Indirect Electroreductive Cyclization and Electrohydrocyclization Using Catalytic Reduced Nickel(II) Salen
作者:James A. Miranda、Carolyn J. Wade、R. Daniel Little
DOI:10.1021/jo051148+
日期:2005.9.1
catalytic nickel(II) salen as a mediator. While nickel(II) salen proved effective, the analogous cobaltcomplex as well as nickel(II) cyclam were not. The transformations were achieved in yields ranging from 60 to 94% using either a mercury pool or an environmentally preferable reticulated vitreous carbon (RVC) cathode. These examples represent the first instances wherein a nickel salen complex has been
A CONVENIENT STEREOSPECIFIC SYNTHESIS OF α,β-UNSATURATED CARBOXYLIC ESTERS VIA THE PALLADIUM-CATALYZED CARBONYLATION OF 1-ALKENYLBORANES
作者:Norio Miyaura、Akira Suzuki
DOI:10.1246/cl.1981.879
日期:1981.7.5
1-Alkenyiboranes readily prepared by the hydroboration of alkynes react smoothly with carbon monoxide in the presence of palladium chloride and sodium acetate in methanol to give the corresponding α,β-unsaturated carboxylic esters with retention of configuration with respect to alkenylboranes in good yields.
Immobilization of the Grubbs second-generation ruthenium-carbene complex on poly(ethylene glycol): a highly reactive and recyclable catalyst for ring-closing and cross-metathesis
作者:Qingwei Yao、Adalie Rodriguez Motta
DOI:10.1016/j.tetlet.2004.01.036
日期:2004.3
catalyst derived from the Grubbs second-generation Ru carbene complex was synthesized and shown to be highly reactive in the ring-closing metathesis of a wide variety of diene substrates, yielding di-, tri-, and tetra-substituted carbocyclic and heterocyclic olefins. The immobilized catalyst also proved to be highly reactive and recyclable in cross-metathesis and ring-opening/cross-metathesis. In all cases