class of electron-deficient reagents for Mitsunobuesterificationreactions. Among these compounds, 4,4′-azopyridine was found to be the most suitable one for esterification and thioesterification reactions. This new reagent promises to provide general and complementary solutions for separation problems in Mitsunobureactions without restricting the reaction scope and facilitates the isolation of its
our findings on a novel and cheap NiCl2 catalytic system under ligand-free conditions for the efficient thiocarbonylation, alkoxycarbonylation and amidocarbonylation reactions of aryl iodides in the presence of Cr(CO)6 as the solid source of carbon monoxide under air. A variety of aryl iodides tolerated the reaction conditions and structurally different thiols, alcohols and amines were used efficiently
Palladium-catalyzed carbonylation of aryl halides: an efficient, heterogeneous and phosphine-free catalytic system for aminocarbonylation and alkoxycarbonylation employing Mo(CO)<sub>6</sub> as a solid carbon monoxide source
Immobilized palladium metal-containing magnetic nanoparticles (ImmPd(0)-MNPs) were synthesized and characterized as an immobilized, phosphine-free catalyst for carbonylation reactions, namely the alkoxycarbonylation and aminocarbonylation reactions. Various substituted aryliodides tolerated the reaction conditions and a wide variety of alcohols and amines were usedefficiently. The effects of the
Carbonylation reaction is a very effective transformation for the synthesis of esters, amides, and heterocyclic compounds. Heterogeneous catalyzed carbonylation reactions can be carried out using the association of Pd/C and microwave dielectric heating. Alkoxy carbonylation can be performed with stoichiometric amounts of different primary and secondary alcohols in DMF in the presence of DBU as the base. Analogously, iodobenzene, CO, and amines can be transformed into the corresponding amides in good yields after a simple filtration to remove the catalyst. Pd/C was also successfully employed in microwave-assisted cyclocarbonylation of o-iodoaniline with acyl chlorides to give benzoxazinones, Pd/C can be recycled two times without a considerable difference in the reaction yields.
Reductive cleavage of resin bound arylsulfonates
作者:Shujuan Jin、David P Holub、David J Wustrow
DOI:10.1016/s0040-4039(98)00640-6
日期:1998.5
A 4-hydroxybenzoate was tethered to a solid support via an arylsulfonate bond. The carboxylate functionality was converted to a variety of esters and amides. The products were then liberated from the resin by Pd(0) catalyzed reductive cleavage of the arylsulfonate oxygen. (C) 1998 Elsevier Science Ltd. All rights reserved.