C-1 Alkynylation of N-Methyltetrahydroisoquinolines through CDC: A Direct Access to Phenethylisoquinoline Alkaloids
作者:Kamal Singh、Paramjit Singh、Amarjit Kaur、Pushpinder Singh
DOI:10.1055/s-0031-1290532
日期:2012.3
Direct cross-coupling between N-methyltetrahydroisoquinolines and alkynes using CuI-DEAD is presented. It affords the regioselective C-1-alkynylated products in good yield. This regioselectivity is in contrast to the results reported earlier in the reaction of N,N-dimethylbenzyl amine where the N-methyl alkynylated product was formed exclusively or predominantly. The C-1-substituted propargylic isoquinolines were easily reduced to phenethylisoquinolines with Pd/C. This reaction sequence provides a short route to synthesize methopholine, homolaudanosine and other phenethylisoquinoline alkaloids.
本文介绍了一种使用CuI-DEAD的N-甲基四氢异喹啉与炔烃之间的直接交叉偶联反应,该反应以高产率选择性地生成了C-1位炔基化的产物。这种区域选择性与先前报道的N,N-二甲基苄胺反应结果形成鲜明对比,后者几乎完全或主要生成N-甲基炔基化产物。C-1位取代的丙炔基异喹啉能通过Pd/C催化轻易还原为苯乙基异喹啉。这一反应序列提供了一条合成甲氧啡啉、同劳丹诺素及其他苯乙基异喹啉生物碱的简捷途径。