Table 2.

Diastereoselective trifluoromethylation of isoxazole triflones 2 a–p.

Entry[a]	2	Ar (or Me)	Ar1	1	d.r.[b]	Yield [%][c]
1	2 a	Ph	Ph	1 a	94:6	91
2[d]	2 b	4-MeC6H4	Ph	1 b	93:7	85
3	2 c	4-MeOC6H4	Ph	1 c	95:5	96
4[d]	2 d	4-ClC6H4	Ph	1 d	97:3	88
5	2 e	4-BrC6H4	Ph	1 e	96:4	90
6	2 f	4-NO2C6H4	Ph	1 f	97:3	80
7[d]	2 g	2-naphthyl	Ph	1 g	96:4	93
8	2 h	2-furanyl	Ph	1 h	99:1	85
9	2 i	Me	Ph	1 i	100:0	64
10	2 j	Ph	4-MeC6H4	1 j	93:7	87
11	2 k	Ph	4-MeOC6H4	1 k	93:7	89
12[d]	2 l	Ph	4-ClC6H4	1 l	94:6	89
13[d]	2 m	Ph	4-BrC6H4	1 m	94:6	89
14	2 n	Ph	4-NO2C6H4	1 n	95:5	92
15[d]	2 o	Ph	2-naphthyl	1 o	96:4	99
16	2 p	3,5-Cl2C6H3	4-MeOC6H4	1 p	95:5	98

^[a]The reaction of 1 with Me₃SiCF₃ (2.0 equiv) was carried out in the presence of KOAc (1.5 equiv) in DMSO at ambient temperature, unless otherwise noted.

^[b]Determined by ¹⁹F NMR.

^[c]Isolated yield. [d] The reaction was carried out with Me₃SiCF₃ (4.0 equiv) and KOAc (3.0 equiv).