Lithiated β-aminoalkyl sulfones as mono and dinucleophiles in the preparation of nitrogen heterocycles: Application to the synthesis of capsazepine
作者:Diego A. Alonso、Ana Costa、Balbino Mancheño、Carmen Nájera
DOI:10.1016/s0040-4020(97)00163-4
日期:1997.3
lithiation of N-benzyl-β-tosylethanamine (10a) and N-benzyl-α-phenyl-β-tosylethanamine (10b) with n-butyllithium at −78°C leads to monoanions 11a and 11b, respectively. Intermediates 11 react with different monoelectrophiles (D2O, alkyl halides, and carbonyl compounds) at the α-position with respect to the sulfone, and with dielectrophiles (1,3-, 1,4-dihalides, α-bromoacetates, and α-chloroketones) to afford
在-78℃下用正丁基锂对N-苄基-β-甲苯磺胺(10a)和N-苄基-α-苯基-β-甲苯磺胺(10b)进行锂化分别产生单阴离子11a和11b。中间体11与相对于砜在α位的不同单亲电子试剂(D 2 O,烷基卤化物和羰基化合物)反应,并与二亲电子试剂(1,3-,1,4-二卤化物,α-溴乙酸酯和α (-氯酮),得到相应的6、7和5元氮杂环。苯并ze庚因衍生物13ae通过11a与4,5-双(氯甲基)-1,2-二甲氧基苯反应获得的α ,被转化成辣椒素25的中间前体24,辣椒素25是感觉神经元兴奋剂辣椒素和树脂毒素的拮抗剂。环状β-氨基砜:N-苄基-3-甲苯磺酰基哌啶(13aa)在轴向位置与锂离子亲电试剂反应生成锂27。在将迈克尔加成至巴豆酸甲酯的情况下,将相应的加合物转化成1-氮杂双环[3.3.1]壬南-2-酮衍生物。最后,用一些代表性的衍生物研究了碱诱导的脱氢亚磺酰化,还原性脱磺酰化和朱莉娅的甲基化。