Nucleophilic Aromatic Addition Reactions of the Metallabenzenes and Metallapyridinium: Attacking Aromatic Metallacycles with Bis(diphenylphosphino)methane to Form Metallacyclohexadienes and Cyclic η2‐Allene‐Coordinated Complexes |
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| Authors: | Hong Zhang Dr. Ran Lin Guangning Hong Tongdao Wang Ting Bin Wen Prof. Dr. Haiping Xia Prof. Dr. |
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| Affiliation: | State Key Laboratory for Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (P.R. China), Fax: (+86)?592‐2186628 |
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| Abstract: | ![]()
The reactions of phosphonium‐substituted metallabenzenes and metallapyridinium with bis(diphenylphosphino)methane (DPPM) were investigated. Treatment of [Os{CHC(PPh3)CHC(PPh3)CH}Cl2(PPh3)2]Cl with DPPM produced osmabenzenes [Os{CHC(PPh3)CHC(PPh3)CH}Cl2{(PPh2)CH2(PPh2)}]Cl ( 2 ), [Os{CHC(PPh3)CHC(PPh3)CH}Cl{(PPh2)CH2(PPh2)}2]Cl2 ( 3 ), and cyclic osmium η2‐allene complex [Os{CH?C(PPh3)CH?(η2‐C?CH)}Cl2{(PPh2)CH2(PPh2)}2]Cl ( 4 ). When the analogue complex of osmabenzene 1 , ruthenabenzene [Ru{CHC(PPh3)CHC(PPh3)CH}Cl2(PPh3)2]Cl, was used, the reaction produced ruthenacyclohexadiene [Ru{CH?C(PPh3)CH?C(PPh3)CH}Cl{(PPh2)CH2(PPh2)}2]Cl2 ( 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 η2‐allene complexes [Ru{CH?C(PPh3)CH?(η2‐C?CH)}Cl{(PPh2)CH2(PPh2)}2]Cl2 ( 7 ) and [Ru{CH?C(PPh3)CH?(η2‐C?CH)}Cl2{(PPh2)CH2(PPh2)}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 [OsCl2{NHC(CH3)C(Ph)C(PPh3)CH}(PPh3)2]BF4 to give the cyclic osmium η2‐allene‐imine complex [OsCl2{NH?C(CH3)C(Ph)?(η2‐C?CH)}{(PPh2)CH2(PPh2)}(PPh3)]BF4 ( 11 ). |
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| Keywords: | metallabenzenes metallacycles metallapyridinium nucleophilic addition transition metals |
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