Results for the three reaction datasets. For each dataset, the mean and standard deviation of R² and MAE of the test set (in parenthesis) were obtained via training each model on 10 random data splits. For Suzuki–Miyaura data, a second column is added which contains the results of the model pre-trained on our synthetic Suzuki–Miyaura data. The results without pretraining are shown for comparison purposes.

	Suzuki–Miyaura	Suzuki–Miyaura (pretrain-synthetic)	Buchwald–Hartwig [HTE]	Buchwald–Hartwig [ELN]
ContextPred	0.540 ± 0.0006 (0.152 ± 0.0004)	0.546 ± 0.0003 (0.151 ± 0.0001)	0.716±6 × 10−4 (0.103±4 × 10−4)	0.177 ± 0.014 (0.220 ± 0.002)
EdgePred	0.540 ± 0.0006 (0.152 ± 0.0003)	0.544 ± 0.0003 (0.152 ± 0.0001)	0.721 ± 0.001 (0.102±1 × 10−4)	0.129 ± 0.011 (0.231 ± 0.002)
AttrMasking	0.535 ± 0.0005 (0.152 ± 0.0004)	0.545 ± 0.0004 (0.152 ± 0.0001)	0.713 ± 0.001 (0.102 ± 0.004)	0.143 ± 0.008 (0.222 ± 0.002)
W/O pretraining	0.635 ± 0.008 (0.133 ± 0.003)	0.635 ± 0.008 (0.133 ± 0.003)	0.6548 ± 0.027 (0.137 ± 0.005)	0.132 ± 0.045 (0.220 ± 0.011)