Table 2.

Arene substituent scope and variable tether length^a

Entry	Ar	n	Product	yield (%)b	ee (%)c
1	Ph	1	2a	64	92
2d	4-MeC6H4	1	2b	40	87
3d	3-MeC6H4	1	2c	42	92
4e	4-CF3C6H4	1	2d	71	>95
5f	4-CF3C6H4	1	2d	51	>95
6	4-MeOC6H4	1	4e	61	--
7d,g	4-MeOC6H4	1	2e	40	70
8	4-ClC6H4	1	2f	53	88
9g	3-ClC6H4	1	2g	58	94
10	4-TsMeNC6H4	1	2h	73	90
11	4-PhC6H4	1	2i	59	20
12h	4-PhC6H4	1	2i	64	56
13	Ph	2	2j	68	93

^aTable 1, entry 1 conditions were applied with 0.1 mmol of substrate 1.

^bIsolated yield of major product following chromatography on silica gel.

^cEnantiomeric excess measured by chiral HPLC.

^d30-40% of an S_N1 product 4 was also formed.

^e25 mol% Cu(OTf)₂ and 31 mol% (S,S)-t-Bu-Box was used.

^f1 mmol of 1d was used. 34% of starting 1d was recovered.

^gCu(NTf₂)₂ was used.

^h(S,S)-i-Pr-Box was used, reaction temperature was 105 °C (at 120 °C, 58% of 2i was obtained in 50% ee).