Functionalization of Alkynes by a (Salen)ruthenium(VI) Nitrido Complex

Abstract

Exploring new reactivity of metal nitrides is of great interest because it can give insights to N2 fixation chemistry and provide new methods for nitrogenation of organic substrates. In this work, reaction of a (salen)ruthenium(VI) nitrido complex with various alkynes results in the formation of novel (salen)ruthenium(III) imine complexes. Kinetic and computational studies suggest that the reactions go through an initial ruthenium(IV) aziro intermediate, followed by addition of nucleophiles to give the (salen)ruthenium(III) imine complexes. These unprecedented reactions provide a new pathway for nitrogenation of alkynes based on a metal nitride.

Four-Electron Oxidation of Phenols to p-Benzoquinone Imines by a (Salen)ruthenium(VI) Nitrido Complex

“…For example, Meyer’s group and others have shown that osmium­(VI) nitrido complexes bearing polypyridyl or tris­(pyrazolylborate) ligands are highly electrophilic and readily react with a variety of nucleophiles to form C–N, P–N, and E–N (E = O, S, Se) bonds. − Novel electrophilic reactivity of iron nitrido complexes has also started to emerge . On the other hand, we have demonstrated that ruthenium­(VI) nitrido complexes bearing salen ligands are highly electrophilic/oxidizing. , For example, the complex [Ru VI (N)­(L)­(CH 3 OH)] + ( 1 , L = N,N ′-bis­(salicylidene)- o -cyclohexyldiamine dianion) readily undergoes C–H activation of alkanes, aziridination of alkenes, nitrogenation of alkynes, and C–N bond cleavage of anilines under ambient conditions.…”

“…5 On the other hand, we have demonstrated that ruthenium(VI) nitrido complexes bearing salen ligands are highly electrophilic/oxidizing. 6,7 For example, the complex [Ru VI (N)(L)(CH 3 OH)] + (1, L = N,N′-bis-(salicylidene)-o-cyclohexyldiamine dianion) readily undergoes C−H activation of alkanes, 8 aziridination of alkenes, 9 nitrogenation of alkynes, 10 and C−N bond cleavage of anilines 11 under ambient conditions.…”

Kinetics and Mechanism of the Reaction of a Ruthenium(VI) Nitrido Complex with HSO3− and SO32− in Aqueous Solution

“…[6] This complex is found to be highly electrophilic/oxidizing. For example, it readily undergoes CÀNb ond cleavage of aniline, [7] CÀHb onda ctivation of alkanes, [8] aziridination of alkenes, [9] and functionalization of alkynes [10] in non-aqueous solvents.…”

Oxidation of ascorbic acid by a (salen)ruthenium(vi) nitrido complex in aqueous solution

“…3 Inspired by the rich electrophilic reactivity of osmium(VI) nitrido complexes supported by polypyridyl ligands, 2,4 we have been interested in studying ruthenium(VI) nitrido complexes bearing salen ligands, such as [Ru VI (N)(L)(MeOH)] + (Ru VI (N), L = N,N 0 -bis(salicylidene)-o-cyclohexyldiamine dianion). [7][8][9] We report herein the kinetics and the mechanism of the reduction of Ru VI (N) by ascorbic acid (H 2 A) in aqueous acidic solutions. [7][8][9] We report herein the kinetics and the mechanism of the reduction of Ru VI (N) by ascorbic acid (H 2 A) in aqueous acidic solutions.…”

“…5 This complex is highly electrophilic, for example, it readily undergoes C-N bond cleavage of aniline, 6 C-H bond activation of alkanes, aziridination of alkenes and functionalization of alkynes in non-aqueous solvents. [7][8][9] We report herein the kinetics and the mechanism of the reduction of Ru VI (N) by ascorbic acid (H 2 A) in aqueous acidic solutions. H 2 A is an important water-soluble antioxidant in chemical and biological systems.…”