A vanadium-promoted C–N bond cleavage

• Published in: Inorganica Chimica Acta Vol. 358; no. 2; pp. 376 - 382
• Main Authors: Egdal, Rune Kirk, Larsen, Frank Bartnik, Bond, Andrew D., McKenzie, Christine J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 25.01.2005
• Subjects: C–N bond cleavage; Mass spectrometry; Vanadium; X-ray diffraction; X-ray diffraction; Mass spectrometry; Vanadium; C–N bond cleavage
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/j.ica.2004.09.004

A C–N bond in one arm of the mixed-valence V III–V IV complex bpbp(VOCl 2)(VCl 2) is cleaved in wet acetonitrile solution to give a secondary amine complex, bpa(VOCl 2), and a protonated primary alcohol, bhbpH 2 +. A C–N bond in one arm of the mixed-valence V III–V IV complex bpbp(VOCl 2)(VCl 2), bpbpH = 2,6-bis(( N, N-bis-(2-picolyl)amino)methyl)-4-tertbutylphenol, is cleaved in wet acetonitrile solution to give bpa(VOCl 2), bpa = bis(2-methypyridyl)amine, and 2-(( N, N-bis-(2-picolyl)amino)methyl)-6-hydroxymethyl-4-tertbutylphenol. The reaction corresponds overall to hydrolysis of a tertiary amine to form a secondary amine and a primary alcohol. The structure of bpa(VOCl 2) was established by X-ray diffraction while 2-(( N, N-bis-(2-picolyl)amino)methyl)-6-hydroxymethyl-4-tertbutylphenol was detected by ESI mass spectrometry. The phenol oxygen atom in bpbp(VOCl 2)(VCl 2) is proposed to be non-bridging and this asymmetry is likely to be important for the C–N bond cleavage reaction. A related asymmetrical V IV complex, [bpbpH(V O)(H 2O)](ClO 4) 2 · H 2O, containing bpbp − bound to only one metal ion, has also been characterized by X-ray diffraction. In slightly more basic solution, bpbp(VOCl 2)(VCl 2) is oxidized to the V IV–V IV complex [bpbp(VOCl) 2] + and C–N bond cleavage is suppressed.