Contrasting reaction pathways were observed in the addition reaction of cyclobutanols to isocyanates in the presence or absence of a rhodium catalyst. Simple heating prompted a direct O‐carbamoylation reaction to afford cyclobutyl carbamates. In contrast, upon addition of a rhodium catalyst, the reaction pathway was directed to C‐carbamoylation through a ring‐opening process.
另一种方法:在存在或不存在
铑催化剂的情况下,
环丁醇与
异氰酸酯的加成反应中观察到相反的反应途径。简单的加热促使O-
氨基甲酸酯化反应直接进行,得到
氨基甲酸环丁酯。相反,在添加
铑催化剂后,反应途径通过开环过程被引导至C-
氨基甲酰基化。