Behavior of dibromocarbene towards substituted aryl aliphatic olefine

It is worth mention to report from the present investigation and HMO calculations that the steric factors play a significant role in controlling the rate of dibromocarbene addition to tri- and tetra-aryl substituted ethylenes [1IOTA -P], a point which far too long lacked emphasis in the literature. Although, occasional references to steric hindrance in carbene addition have been reported but nevertheless, emphasis is more generally placed on electronic effects