Title of article :
Silver(I) complexes of fluorinated scorpionates: Ligand effects in silver catalyzed carbene insertion into C–H bonds in alkanes
Author/Authors :
Krishnan Rangan، نويسنده , , Mauro Fianchini، نويسنده , , Shreeyukta Singh، نويسنده , , H.V Rasika Dias، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2009
Pages :
6
From page :
4347
To page :
4352
Abstract :
Activation of C–H bonds of hydrocarbons via intermolecular carbene insertion has been investigated using tris(pyrazolyl)boratosilver(I) catalysts [MeB(3-(CF3)Pz)3]Ag(C2H4), [MeB(3-(C2F5)Pz)3]Ag(C2H4) and [HB(3,5-(CF3)2Pz)3]Ag(C2H4). Cyclopentane, 2-methylbutane, and 2,3-dimethylbutane were used as substrates. Carbenes derived from ethyl and tert-butyl diazoacetates have effectively been inserted into tertiary, secondary, as well as primary C–H bonds of hydrocarbons at room temperature using these catalysts. Tertiary C–H bonds in these substrates get preferentially activated over secondary C–H followed by primary C–H bonds. However, it is possible to increase the amount of primary C–H bond activated product by utilizing catalysts with increasingly acidic silver sites and sterically bulky tris(pyrazolyl)borate ligands. The carbene insertion into primary C–H bonds increases in the order: [MeB(3-(CF3)Pz)3]Ag(C2H4) < [MeB(3-(C2F5)Pz)3]Ag(C2H4) < [HB(3,5-(CF3)2Pz)3]Ag(C2H4). The carbene derived from tert-butyl diazoacetate with these catalysts shows slightly lower selectivity for primary C–H bonds compared to the ethyl diazoacetate-based carbene.
Keywords :
Catalysis , Tris(pyrazolyl)borate , Silver
Journal title :
INORGANICA CHIMICA ACTA
Serial Year :
2009
Journal title :
INORGANICA CHIMICA ACTA
Record number :
1327823
Link To Document :
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