Nucleophilic aromatic addition reactions of the metallabenzenes and metallapyridinium: attacking aromatic metallacycles with bis(diphenylphosphino)methane to form metallacyclohexadienes and cyclic eta(2)-allene-coordinated complexes

Hong Zhang; Ran Lin; Guangning Hong; Tongdao Wang; Ting Bin Wen; Haiping Xia

doi:10.1002/chem.201000324

Nucleophilic aromatic addition reactions of the metallabenzenes and metallapyridinium: attacking aromatic metallacycles with bis(diphenylphosphino)methane to form metallacyclohexadienes and cyclic eta(2)-allene-coordinated complexes

Chemistry. 2010 Jun 18;16(23):6999-7007. doi: 10.1002/chem.201000324.

Authors

Hong Zhang¹, Ran Lin, Guangning Hong, Tongdao Wang, Ting Bin Wen, Haiping Xia

Affiliation

¹ State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, PR China.

PMID: 20437427
DOI: 10.1002/chem.201000324

Abstract

The reactions of phosphonium-substituted metallabenzenes and metallapyridinium with bis(diphenylphosphino)methane (DPPM) were investigated. Treatment of [Os{CHC(PPh(3))CHC(PPh(3))CH}Cl(2)(PPh(3))(2)]Cl with DPPM produced osmabenzenes [Os{CHC(PPh(3))CHC(PPh(3))CH}Cl(2){(PPh(2))CH(2)(PPh(2))}]Cl (2), [Os{CHC(PPh(3))CHC(PPh(3))CH}Cl{(PPh(2))CH(2)(PPh(2))}(2)]Cl(2) (3), and cyclic osmium eta(2)-allene complex [Os{CH=C(PPh(3))CH=(eta(2)-C=CH)}Cl(2){(PPh(2))CH(2)(PPh(2))}(2)]Cl (4). When the analogue complex of osmabenzene 1, ruthenabenzene [Ru{CHC(PPh(3))CHC(PPh(3))CH}Cl(2)(PPh(3))(2)]Cl, was used, the reaction produced ruthenacyclohexadiene [Ru{CH=C(PPh(3))CH=C(PPh(3))CH}Cl{(PPh(2))CH(2)(PPh(2))}(2)]Cl(2) (6), which could be viewed as a Jackson-Meisenheimer complex. Complex 6 is unstable in solution and can easily be convert to the cyclic ruthenium eta(2)-allene complexes [Ru{CH=C(PPh(3))CH=(eta(2)-C=CH)}Cl{(PPh(2))CH(2)(PPh(2))}(2)]Cl(2) (7) and [Ru{CH=C(PPh(3))CH=(eta(2)-C=CH)}Cl(2){(PPh(2))CH(2)(PPh(2))}(2)]Cl (8). The key intermediates of the reactions have been isolated and fully characterized, further supporting the proposed mechanism for the reactions. Similar reactions also occurred in phosphonium-substituted metallapyridinium [OsCl(2){NHC(CH(3))C(Ph)C(PPh(3))CH}(PPh(3))(2)]BF(4) to give the cyclic osmium eta(2)-allene-imine complex [OsCl(2){NH=C(CH(3))C(Ph)=(eta(2)-C=CH)}{(PPh(2))CH(2)(PPh(2))}(PPh(3))]BF(4) (11).