Table 1. Deviation from the optimal reaction conditions for the α,α′-trifluoromethylthiolation–phenylation of diazoketone 2a ^a .

Entry	Deviation from the standard conditions	Yield b (%)
1	None	81
2	0.25 equiv. Zn(NTf2)2 (4)	37
3	Without Zn(NTf2)2 (4)	<5
4	Rh2(OAc)4 (5 mol%) instead of 4	0
5	Pd(OAc)2 (15 mol%) instead of 4	30
6	Zn(OTf)2 instead of 4	<5
7	0.5 equiv. of 3c	28
8	Na(BPh4) instead of 3c	52
9	(PhBO)3 (3a) instead of 3c, without 4	0
10	BPh3 (3b) instead of 3c, without 4	15
11	ZnPh2 instead of 3c	<5
12	ZnPh2 instead of 4 and BPh33b instead of 3c	0
13	PhMe as the solvent	71
14	THF as the solvent	35
15	MeCN as the solvent	0
16	Without 3Å ms	59
17	22 °C instead of –10 °C	66

^aTo reagent 1 (0.1 mmol), Bu₄N(BPh₄) (3c) (0.15 mmol), Zn(NTf₂)₂ (4) (0.05 mmol) and 80 mg 3Å molecular sieves (ms) was added a solution of diazoketone 2a (0.15 mmol) in CH₂Cl₂ (1.0 ml) at –10 °C. This mixture was stirred at –10 °C for 2 h before allowing it to warm up to RT overnight.

^bIsolated yield.