A direct C-H arylation of free-(NH2) adenines using Pd(OH)(2)/C (Pearlman's catalyst) and stoichiometric amount of copper iodide under ligandless microwave activation is described. This new protocol proved to be highly effective to synthesize a variety of 8-aryladenine derivatives 3 without prior protection of the amino substituent. The arylation reaction takes place rapidly within few Minutes and allows the coupling to proceed regioselectively at the 8-position with a wide range of aryl halides including aryl iodides, bromides and the less reactive aryl chlorides. (C) 2008 Elsevier Ltd. All rights reserved.
A site selective C–H arylation of free-(NH2) adenines with aryl chlorides: Application to the synthesis of 6,8-disubstituted adenines
An efficient site selective method for the direct arylation of free-(NH2) adenines 1 to provide a range of C-8 arylated adenines 3 in excellent yields is described. This process based on the use of Pd(OH)2/C as the catalyst and a stoichiometric amount of CuI under ligandless conditions is general. It allows the coupling to proceed with a variety of aryl halides, including for the first time cheaper
描述了一种用于自由-(NH 2)腺嘌呤1的直接芳基化的有效位点选择方法,以优异的产率提供了一系列C-8芳基化的腺嘌呤3。通常基于在无配体条件下使用Pd(OH)2 / C作为催化剂和化学计量的CuI的方法。它可以使偶联反应与各种芳基卤化物进行,包括第一次更便宜,反应性更低的芳基氯化物。还报道了该方法的扩展用于顺序制备非对称的C8 / N 6-芳基腺嘌呤4。