The ethyl oxazole-4-carboxylate was directly and regioselectively alkenylated, benzylated and alkylated with alkenyl-, benzyl-, allyl- and alkylhalides in the presence of catalytic amounts of palladiumacetate with caesium carbonate using Buchwald's JohnPhos ligand.
A catalytic system comprised of Pd(OAc)2 and bidentate ligand dppe enabled first direct arylations with moisture-stable aryl sulfamates as electrophiles, and proved applicable to unprecedented C−H bond functionalizations with easily accessible alkenyl phosphates as well as benzyl phosphates.
New pyridin-3-ols and their N-oxides and acid addition salts, which are useful as intermediates, especially for the preparation of pharmacologically active compounds, and their preparation.
An efficient preparation of 2-alkyl-oxazoles from 2-iodooxazoles
作者:Xing Zhang、Jun Liu、Yi Liu、Yuguo Du
DOI:10.1016/j.tetlet.2013.05.088
日期:2013.7
An efficient synthesis toward 2-alkyl substituted oxazoles has been achieved through Suzuki cross-coupling reaction. Treatment of various alkyl iodides with 9-MeO-BBN, followed by in situ palladium-catalyzed carbon-carbon formation with 2-iodooxazoles obtained the 2-alkyl substituted oxazoles in good to excellent yields. Regioselective C2-alkylation on 2,4-di-iodooxazole under the same reaction conditions was firstly disclosed. (C) 2013 Elsevier Ltd. All rights reserved.
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