at alkenes 4 on the rates and activation parameters of cycloaddition reactions of bromocarbethoxycarbene (3) is very small. This carbene does not fit into the general equation (b) and the isoselective relationship (c) of dihalocarbenes. The deviating behaviour can be explained by a diffusion controlled reaction rate of bromocarbethoxycarbene.
烯烃4上的Me取代基对
溴碳乙氧基卡宾(3)的环加成反应的速率和活化参数的影响很小。该卡宾不符合通式(b)和二卤卡宾的等选择关系(c)。偏差行为可以通过
溴碳乙氧基卡宾的扩散控制的反应速率来解释。