US EPA

1703891 

Journal Article 

Regioselective ortho-Metallation of 2-Diphenylphosphanylpyridine and (2-(2-Diphenylphosphanyl)phenyl)-1-3-dioxalane with Methyltetrakis(trimethylphosphane)cobalt(I) 

Beck, R; Sun, H; Li, X; Klein, HF 

2009 

1 

Zeitschrift fuer Anorganische und Allgemeine Chemie
ISSN: 0044-2313 

635 

1 

99-105 

10.1002/zaac.200800309 

WOS:000262738500014 

Co(CH(3))(PMe(3))(4) forms 100% regioselectively with (2-(2-diphenylphosphanyl)phenyl)-1,3-dioxalane and 2-diphenyl-phosphanyl-pyridine. by elimination of methane, the four-membered metallacycles CO{(C(3)O(2)HC(6)H(3))P(C(6)H(5))(2)}(PMe(3))(3) (1) and Co{CNC(4)H(3))P(C(6)H(5))(2)}(PMe(3))(3) (4). The regioselectivity is independent of the steric requirement Of the ortho substituent in the 2-diphenylphosphanylaryl-ligands. Oxidative addition with iodomethane transforms 1 and 4 into octahedral, diamagnetic low-spin d(6) complexes Co(CH(3))I-{(C(3)O(2)HC(6)H(3))P(C(6)H(5))(2) (pMe(3))(2) (2) and CO(CH(3))I-{(CNC(4)H(3),)P(C(6)H(5))(2)}(PMe(3))(2) (5). Under an atmosphere of carbon monoxide, insertion into the Co-C bond results in ring expansion by forming the new assembled phosphanylbenzoyl complexes CO{(C(4)O(3)HC(6)H(3))-P(C(6)H(5))(2)}CO(PMe(3))(2) Co{(OCNC(4)H(3))P(C(6)H(5))(2)}CO(PMe(3))(2) (6). The three different types of cobaltacycles are Supported by X-ray diffraction of 1, 3, 5 and 6. 

C-H-Activation; Metallation (ortho); Cobalt; Insertion reactions; P ligands