Origin of the Deactivation in Styrene Aziridination by Aryl Azides, Catalyzed by Ruthenium Porphyrin Complexes. Structural Characterization of a Δ2-1,2,3-Triazoline RuII(TPP)CO Complex
摘要:
The reaction of Ru(TPP)CO (TPP = dianion of tetraphenylporphyrin) with 1-(p-nitrophenyl)-5-methyl-5-phenyl- 1,2,3-triazoline yielded a Delta(2)-1,2,3-triazoline ruthenium(II) porphyrin complex, which is responsible for the catalyst deactivation in the aziridination reaction of (x-methylstyrene by p-nitrophenyl azide.
A mechanism for the aziridination of olefins by arylazides (ArN3), promoted by ruthenium(II) porphyrin complexes, is proposed on the basis of kinetic and theoretical studies. All the recorded data support the involvement of a mono-imido ruthenium complex as the active intermediate in the transfer of the nitrene moiety “ArN” to the olefin. The selectivity of the aziridination vs. the uncatalysed triazoline