Table 1.

Optimization and control studies.

Entry	Variation from optimized conditions	Yield (%)a
1	None	92 (89)b
2	P(OEt)3 instead of PPh3	84
3	[Ir(dFCF3ppy)2dtbbpy)](PF6) (1 mol %)	83
4	Na2CO3 instead of NaOtBu	0
5	No CS2	0
6	No PPh3	0
7	No photocatalyst	0
8	No light	0
9	Without H2O	26
10	3a (1.0 equiv)	66
11	PPh3 (0.20 equiv)	20
12	PPh3 (0.20 equiv) + reductants (2.0 equiv)	<20

Standard procedure: 1aa (0.20 mmol), NaO^tBu (1.0 equiv), THF (1.2 mL), CS₂ (1.5 equiv), 3 h. After removing solvent in vacuo, then 3a (2.0 equiv), [Ir(ppy)₂dtbbpy](PF₆) (1 mol%), PPh₃ (1.2 equiv), H₂O (7.0 equiv), MeCN (2.0 mL), 24 h blue LED irradiation.

Boc t-butoxycarbonyl.

^aDetermined by ¹H NMR analysis using 1,3,5-trimethoxybenzene as an internal standard.

^bIsolated yield.