Abstract Supported palladium nanoparticles on Mn-carboxylate coordination polymer (Pd/MnBDC) were prepared using solution impregnation method. This new catalyst was characterized by XRD, SEM, TEM, EDX, XPS, FTIR and TGA analysis. The Pd/MnBDC exhibits efficient catalytic activity for the Mizoroki–Heck coupling reaction between iodobenzene and either aromatic or aliphatic terminal alkenes and reuses
Résumé Palladium nanoparticles (Pd-NPs) were supported on functional and nonfunctional Co-coordination polymers (Pd/CoBDCNH2 and Pd/CoBDC). Advanced analytical techniques revealed that Pd-NPs are supported on the external surface of the polymer framework and the functionalized framework possesses effective influence to prevent Pd-NP aggregation. Supported Pd-NPs were effectively applied as heterogeneous recyclable catalysts in the Mizoroki–Heck C–C cross coupling reactions of iodobenzene and either aromatic or aliphatic terminal alkenes. Catalytic results exhibited that highly dispersed Pd-NPs with low loading (1%) on the functional polymer (Pd/CoBDCNH2) are more effective than aggregated Pd-NPs with high loading (9%) on the nonfunctional polymer (Pd/CoBDC). Both catalysts can simultaneously provide high activity and selectivity to E-coupled products, high efficiency in low amounts, easy separation of heterogeneous catalyst and appropriate performance in the recycling reaction without addition of a reducing agent.
The mechanism of the norrish type II reaction of α-keto-acids and esters
作者:R.Stephen Davidson、Dean Goodwin、Ph.Fornier de Violet
DOI:10.1016/s0040-4039(01)92939-9
日期:1981.1
Methyl-α-keto-octanoate undergoes a TypeII reaction to give pent-1-ene and photophysical measurements show that this and the TypeII reactions of α-keto-acids occur, contrary to previous claims, from the excited singlet state.
Metal-free one-pot synthesis of quinoline-2,4-carboxylates via a molecular iodine-catalyzed three-component reaction of arylamines, ethyl glyoxylate, and α-ketoesters
作者:Guang-Ming Nan、Wei Liu
DOI:10.1016/j.cclet.2015.06.015
日期:2015.10
A simple and metal-free method has been developed for the construction of quinoline-2,4-carboxylates under mild conditions via a molecular iodine-catalyzed three-component tandem reaction of arylamines, ethyl glyoxylate, and alpha-ketoesters. The present protocol provides a convenient and attractive approach to various quinoline-2,4-carboxylates in moderate to good yields with excellent functional group tolerance. (C) 2015 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.