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Synthesis of Osmapyridiniums by [4+2] Cycloaddition Reaction between Osmium Alkenylcarbyne and Nitriles
Author(s) -
Liu Bin,
Zhao Qianyi,
Wang Huijuan,
Chen Jinxiang,
Cao Xiaoyu,
Cao Zexing,
Xia Haiping
Publication year - 2012
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201200650
Subject(s) - chemistry , osmium , medicinal chemistry , cycloaddition , stereochemistry , acetonitrile , ruthenium , catalysis , organic chemistry
A novel [4+2] cycloaddition reaction between osmium alkenylcarbyne complex [OsHCl 2 {CC(PPh 3 )CHPh}(PPh 3 ) 2 ] + BF 4 − ( 1 ) and nitriles (acetonitrile and benzonitrile) provided metallapyridiniums [OsCl 2 {CHC(PPh 3 )CPhCRNH}(PPh 3 ) 2 ] + BF 4 − (R=CH 3 ( 2 ), Ph ( 3 )) and OsCl 3 {CHC(PPh 3 )CPhCPhNH}(PPh 3 ) ( 4 ). A possible mechanism was proposed. Treatment of 2 with n ‐BuLi and NEt 3 afforded osmapyridines OsCl 2 {CHC(PPh 3 )CPhCCH 3 N}(PPh 3 ) 2 ( 5 ) and [OsCl{CHC(PPh 3 )CPhCCH 3 N}(C 6 H 5 N)(PPh 3 ) 2 ] + BF 4 − ( 6 ). The ligands of osmapyridiniums 2 and 4 were changed, thus providing a series of osmapyridiniums [OsCl(SCN){CHC(PPh 3 )CPhC(CH 3 )NH}(PPh 3 ) 2 ] + Cl − ( 7 ), OsCl(SCN) 2 {CHC(PPh 3 )CPhC(CH 3 )NH}(PPh 3 ) ( 8 ), Os(SCN) 3 {CHC(PPh 3 )CPhC(CH 3 )NH}(PPh 3 ) ( 9 ), [OsCl{CHC(PPh 3 )CPhC(CH 3 )NH}(CH 3 CN)(PPh 3 ) 2 ] + (BF 4 −) 2 ( 10 ), [OsCl{CHC(PPh 3 )CPhC(CH 3 )NH}‐( η 2 ‐1,10‐phenanthroline)(PPh 3 )] + (BF 4 −)Cl − ( 11 ), [OsCl{CHC(PPh 3 )CPhC(CH 3 )NH}(η 2 ‐8‐hydroxyquinoline) (PPh 3 )] + BF 4 − ( 12 ), and [Os{CHC(PPh 3 )CPhCPhNH}(CH 3 CN) 3 (PPh 3 )] + (BF 4 −) 3 ( 13 ). Most of these products were characterized by NMR spectroscopy, elemental analysis and single crystal X‐ray diffraction.