Impact of\nthe Olefin and Diazene Structure on the\nHeterofunctional Azo Metathesis Catalyzed by the First-Generation\nGrubbs Catalyst

In this work, we computationally studied the influence\nof the change\nin the substrate structure on the course of the heterofunctional cross-metathesis\nreaction between azo compounds and olefins catalyzed by the first-generation\nGrubbs catalyst. The highest reaction rates were predicted for symmetric,\nbulky diazenes and sterically uncrowded olefins. Other studied azo\ncompounds have much higher energy barriers in the crucial steps in\nthe catalyst initiation phase, while larger olefins are characterized\nby high energy barriers in the second part of the catalytic cycle.\nOur analysis suggests that Grubbs-like catalysts can be efficiently\nused in heterofunctional azo metathesis only for a limited number\nof olefin-azo compound combinations, such as 1,2-diphenyldiazene and\nethylene to produce N-phenylmethanimine.