Microwave-assisted Sonogashira-type cross couplings of various heterocyclic methylthioethers
摘要:
A novel, microwave-assisted. palladium-catalyzed Sonogashira-type coupling of terminal alkynes with a variety of heteroaryl thiomethylethers is reported. The developed protocol allows for further utility and diversification of a number of chemically and biologically interesting scaffolds, (C) 2008 Elsevier Ltd. All rights reserved.
The regioselective synthesis of 2-alkynyl(benz)imidazoles was successfully achieved by Pd(ii)/Ag(i)-mediated dehydrogenative alkynylation of the corresponding (benz)imidazoles with terminal alkynes in an open vessel.
Cu2O/PPh3/TBAB (n-Bu4NBr) system for the cross-couplingreactions of aryl and heteroarylhalides with terminal alkynes has been developed. Four types of Cu2O, including bulky Cu2O, cubic Cu2O nanoparticles, octahedral Cu2O nanoparticles, and spherical Cu2O nanoparticles, were examined, and the octahedral Cu2O nanoparticles were found to be the most effective catalyst for the reaction. In the presence of the octahedral
Conjugated imines and iminium salts as versatile acceptors of nucleophiles
作者:Makoto Shimizu、Iwao Hachiya、Isao Mizota
DOI:10.1039/b814930e
日期:——
development of synthetic methodologies where nucleophilicaddition reactions to imino carbons are utilized in crucial steps. This article summarizes double nucleophilicaddition reactions with alpha,beta-unsaturated aldimines, addition reactions using alkynyl imines, "umpoled" reactions of alpha-imino esters, and the use of iminium salts as reactive electrophiles.
The synthesis of multi-substituted 2-iminopyridines by conjugate addition of ethyl cyanoacetatederivatives to alkynyl imines has been developed. The reaction of ethyl cyanoacetatederivatives with alkynyl imines provided multi-substituted 2-iminopyridines in good yields. Also described is the transformation of 2-iminopyridines into 2-aminopyridines by deprotection of the substituent on the nitrogen
Sonogashira cross-coupling reactions with heteroaryl halides in the presence of a tetraphosphine–palladium catalyst
作者:Marie Feuerstein、Henri Doucet、Maurice Santelli
DOI:10.1016/j.tetlet.2005.01.044
日期:2005.3
Heteroaryl halides undergoes cross-couplings with alkynes in good yields in the presence of [PdCl(C3H5)]2/cis,cis,cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as catalyst. A variety of heteroaryl halides such as pyridines, quinolines, a pyrimidine, an indole, a thiophene, or a thiazole have been used successfully. The reaction also tolerates several alkynes such as phenylacetylene and
在[PdCl(C 3 H 5)] 2 /顺式,顺式,顺式-1,2,3,4-四(二苯基膦甲基)环戊烷的存在下,杂芳基卤化物与炔烃进行交叉偶联,收率很高。已经成功地使用了各种杂芳基卤化物,例如吡啶,喹啉,嘧啶,吲哚,噻吩或噻唑。该反应还可以耐受几种炔烃,例如苯乙炔和一系列烷-1-炔醇。此外,该催化剂可在低负荷下与某些底物一起使用。