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)。