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[摘要]:Rate constants for hydrogen abstraction by a nonyl radical from 20 complexes of N-heterocyclic carbenes and boranes (NHC-boranes) have been determined by the pyridine-2-thioneoxycarbonyl (PTOC) competition kinetic method at a single concentration point. The rate constants range from <1 x 10(4) to 8 x 10(4) M-1 s(-1). They show little dependence on the electronic properties of the carbene core, but there is a trend for increasing rate constants with decreasing size of the carbene N-substituents. Two promising new reagents with small N-substituents (R = Me) have been identified. |
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