Efficient palladium(II)-catalyzed homocoupling of thiazole-4-carboxylic or oxazole-4-carboxylic derivatives
摘要:
An efficient Pd(OAc)(2)-catalyzed homocoupling of thiazole-4-carboxylic or oxazole-4-carboxylic derivatives is described. It represents a facile and practical methodology to prepare bis-5,5'-thiazole (oxazole)-4,4'-dicarboxylic derivatives in good to excellent yields. This protocol tolerates a series of substitutions on the thiazole (oxazole) rings, including alkyl, carbonyl, and electron-withdrawing/donating group substituted phenyl groups. (C) 2011 Elsevier Ltd. All rights reserved.
Environmental-benign oxidation of 2-oxazolines to oxazoles by dioxygen as the sole oxidant
摘要:
A facile and environment-benign oxidation by dioxygen as the sole oxidant was applied for the conversion of 2-oxazolines to oxazoles. The substituent effect on 2-oxazoline ring was investigated. The use of this methodology for the synthesis of a key intermediate of a CDC25 phosphatase inhibitor (SC-alpha alpha delta 9) as an anticancer agent was also described. (C) 2011 Elsevier Ltd. All rights reserved.