A Synthesis of 3-Phenyl-1,2,3,4-tetrahydroisoquinoline and 2-Phenyl-1,2,4,5-tetrahydro-3H-3-benzazepine via Pummerer-Type Cyclization: Enhancing Effect of Boron Trifluoride Diethyl Etherate on the Cyclization.
作者:Toshiaki SAITOH、Tsuyoshi ICHIKAWA、Yoshie HORIGUCHI、Jun TODA、Takehiro SANO
DOI:10.1248/cpb.49.979
日期:——
vinyl sulfides (8a, b), non-cyclized products, as a major product. The cyclization proceeded when boron trifluoride diethyl etherate was used as an additive reagent, thus giving rise to the corresponding cyclized products (7a) and (7b) in moderate yields. We propose that the enhancing effect of the Lewis acid on the cyclization may be attributable to the involvement of a dicationic intermediate, sulfonium-carbenium
6,7-二甲氧基-3-苯基-1,2,3,4-四氢异喹啉(14a)和7,8-二甲氧基-2-苯基-1,2,4,5-四氢-3H-3-的合成通过将N-(3,4-二甲氧基苯基)甲基-1-苯基-2-(苯基亚磺酰基)乙基甲酰胺(6a)和N-2-(3,4-二甲氧基苯基)乙基-1-环化获得苯并ze庚因(14b)分别使用Pummerer反应作为关键步骤的苯基-2-(苯基亚磺酰基)-乙基甲酰胺(6b)。在三氟乙酸酐的常规条件下,6a,b的Pummerer反应产生了作为主要产物的非环化产物乙烯基硫化物(8a,b)。当三氟化硼二乙基醚化硼用作添加剂时,进行环化反应,从而以中等收率得到相应的环化产物(7a)和(7b)。