Table 1.

Optimization of catalytic Umpolung amidation conditions^a.

Entry	Variation of standard conditions	Yield(%)b
1	None	95
2	P-B instead of P-A	40
3	P-C instead of P-A	30
4	P-D instead of P-A	Trace
5	P-E instead of P-A	8
6	P-F instead of P-A	Trace
7	FeCl2 instead of FeI2	38
8	Fe(acac)3 instead of FeI2	Trace
9	Ph2SiH2 instead of PhSiH3	18
10	Et3SiH instead of PhSiH3	Trace
11	Without photocatalyst PC-I	ND
12	Without organocatalyst P-A	ND
13	Without FeI2	Trace
14	Without light irradiation	ND

ND not detected.

^aStandard conditions: 1a (0.1 mmol), 2a (0.12 mmol), PC-I (1 mol%), P-A (30 mol%), FeI₂ (15 mol%), K₂HPO₄ (0.5 equiv), PhSiH₃ (0.5 mmol), MeCN (2 ml), blue LEDs, ambient temperature, 24 h.

^bIsolated yield.