Reactions of Organic Nitriles with a Three-Coordinate Molybdenum(III) Complex and with a Related Molybdaziridine-Hydride

• Published in: Organometallics 2003-07, Vol.22 (14), p.2902-2913
• Main Authors: Tsai, Yi-Chou, Stephens, Frances H, Meyer, Karsten, Mendiratta, Arjun, Gheorghiu, Mircea D, Cummins, Christopher C
• Format: Article
• Language: English
• ISSN: 0276-7333; 1520-6041
• DOI: 10.1021/om030124v

Reactions of nitriles RCN with the sterically encumbered Mo(N[t-Bu]Ar)3 (1, Ar = 3,5-C6H3Me2) or the somewhat less hindered Mo(H)(η2-Me2CNAr)(N[i-Pr]Ar)2 (2) have been investigated. Where R = Me or Ph, reaction with 1 results in reductive nitrile coupling and the formation of a diiminato product [μ-NC(R)C(R)N][1]2. In contrast, reaction of 1 with Me2NCN surprisingly results in a stable, albeit highly congested, η2 adduct of the nitrile. When the less sterically hindered 2 is used, reaction with PhCN gives the diiminato product analogous to the one mentioned for the tert-butyl system, [μ-NC(Ph)C(Ph)N][Mo(N[i-Pr]Ar)3]2, where molybdaziridine-hydride 2 has provided access to the three-coordinate Mo(N[i-Pr]Ar)3 (3) moiety. Use of a more bulky nitrile such as MesCN (Mes = 2,4,6-C6H2Me3) results in formation of a bis-η1 compound, (η1-MesCN)2[3]. Use of 9-anthracenylcarbonitrile results in head-to-tail C−C coupling of two monomers via the anthracenyl moiety. Detailed variable-temperature EPR and 2H NMR data are included for both molybdenum-containing starting materials and selected reaction intermediates and products.