Palladium-catalyzed coupling of steroid 17-iodo-6β-methoxy-3α,5-cyclo-5α-androst-16-ene (4) 17-iodoandrosta-5,16-dien-3β-ol (5), and structurally similar (3aS,7R,7aR)-benzenesulfonyl-3-iodo-3a-methyl-3a,4,5,6,7,7a-hexahydro-1H-indene (6) with various arylzinc chlorides, which were generated from aryl bromides 8 [1-bromomethylbenzene (8a), O-(triethylsilyl-2-bromophenyl)propan-2-ol (8b), 2-(4-bromophenyl)propan-2-ol (8c), 4-bromobenzonitrile (8d), 4-bromobenzoic acid methyl ester (8e), 4-bromobenzoic acid tert-butyl ester (8f) and 3-bromopyridine (8g)] via aryllihium derivatives (the Negishi coupling) was examined. The respective cross-coupling products were obtained in good yields for all aryl bromides except of 8c and 8e. Building blocks for synthesis of certain vitamin D analogues have been prepared.
使用钯催化剂将类固醇17-碘-6β-甲氧基-3α,5-环-5α-雄烷-16-烯(4),17-碘雄甾-5,16-二烯-3β-醇(5)和结构类似的(3aS,7R,7aR)-苯磺酰基-3-碘-3a-甲基-3a,4,5,6,7,7a-六氢-1H-茚烷(6)与各种芳基锌氯化物进行偶联反应,这些锌氯化物是由芳基溴化物8 [1-溴甲基苯(8a),O-(三乙基硅基-2-溴苯基)丙烷-2-醇(8b),2-(4-溴苯基)丙烷-2-醇(8c),4-溴苯甲腈(8d),4-溴苯甲酸甲酯(8e),4-溴苯甲酸叔丁酯(8f)和3-溴吡啶(8g)] 通过芳基锂衍生物(Negishi偶联)生成。除了8c和8e之外,所有芳基溴化物的交叉偶联产物均可得到良好的收率。已准备用于合成某些维生素D类似物的构建块。