Table 1. Lewis Acid Optimization^a.

entry	Lewis acid	solvent	yield (%)b
1	none	t-amylOH	nr
2	Ca(NTf2)2	t-amylOH	>99
3	Ca(OTf)2	t-amylOH	10
4	Mg(NTf2)2	t-amylOH	50
5	Ba(NTf2)2	t-amylOH	72
6	Li(NTf2)	t-amylOH	13
7	Zn(NTf2)2	t-amylOH	3
8	B(C6F5)3	t-amylOH	3
9	Ca(NTf2)2	t-BuOH	76
10	Ca(NTf2)2	CH3CN	55
11	Ca(NTf2)2	toluene	53

^aReaction conditions: sulfonimidoyl fluoride (1 equiv), aniline (2 equiv), Lewis acid (1 equiv), t-amylOH (0.2 M), 80 °C, and 5 h.

^bYield was determined by HPLC.