Table 1 The TON of heterogeneous catalyst HB-Pd/C and homogeneous catalyst Pd(TFA)2 under different reaction conditions.

Under a low turnover condition, the substrate/catalyst ratio is 100:3; under a high turnover condition, the substrate/catalyst ratio is 1000:3; and under an ultrahigh turnover condition, the substrate/catalyst ratio is 10,000:3.

EntryCatalystLow turnoverHigh turnoverUltrahigh turnover
1HB-Pd/C31314>3000 (linear)
2Pd(TFA)22028