In the Dark and in the Light: Homogeneous and Heterogeneous Catalytic Activation of 1,2-Diazenes
31 December 2000 (online)
The N=N bond of a 1,2-diazene is activated for thermal and photochemical C-N coupling with alkynes and olefins respectively. In the first case iron carbonyls assist the formation of 1,2,3-diazepinones from cyclic diazenes while cobalt(I) and rhodium(I) complexes catalyze mono- or double insertions into the ortho-C-H bonds of azobenzenes affording 2-stilbenylazobenzenes and N-anilinoindole derivatives, respectively. In the second case allylhydrazines are synthesized by semiconductor (ZnS, CdS) photocatalyzed addition of olefins or allyl/enol ethers to azobenzenes.
insertion of alkynes - transition metal catalysis - semiconductor - photochemistry - 1,2-Diazenes