Table 1. Effect of reaction parameters ^a .

Entry	Variations from “standard” conditions	Yield (%) (rsm) b
1	None	72 (22)
2	Without CuI	25 (66)
3	Without CuI	39 (45) c
4	CuBr instead of CuI	33 (50)
5	CuBr2 instead of CuI	31 (58)
6	Cu(OAc)2 instead of CuI	52 (22)
7	Cu(OTf)2 instead of CuI	20 (68)
8	Without Br2	31 (64)
9	Without TBAB	6 (89)
10	TBAB3 f instead of TBAB	38 (39)
11	DCE instead of DCM	31 (42)
12	CHCl3 instead of DCM	25 (54)
13	PhCl instead of DCM	10 (57)
14	120 °C instead of 100 °C	69 (22)
15	80 °C instead of 100 °C	59 (24)

^aReaction was conducted on a 0.1 mmol scale.

^brsm: recovered starting material; yields were determined by ¹H NMR analysis versus 1,1,2,2-tetrachloroethane as the internal standard.

^cReaction time is 24 h.

^dND: not detected. Determined by crude ¹H NMR.

^eDetected by crude ¹H NMR.

^fTBAB₃: tetrabutylammonium tribromide.