Table 1.

Optimization of reaction conditions

Entry	R1	R2	Ionic liquid	Product	Reaction time	Yield (%)
1	H	H	[BMIM]Cl	—	12 h	—
2	H	H	[BMIM]BF4	—	12 h	—
3	H	H	[BMIM]BF4–LiCl	3a	20 min	90
4	H	H	TMGTf	3a	10 min	92
5	Me	H	[BMIM]Cl	—	12 h	—
6	Me	H	[BMIM]BF4	—	12 h	—
7	Me	H	[BMIM]BF4–LiCl	3b	20 min	92
8	Me	H	TMGTf	3b	10 min	93