Table 1.

Optimization of the reaction conditions^a

Entry	L	“N3”	Solvent	Time (h)	Yield (%)	ee (%)
1	L1	1a	DCE	24	35	14
2	L2	1a	DCE	24	28	12
3	L3	1a	DCE	24	50	23
4	L4	1a	DCE	24	37	75
5	L5	1a	DCE	24	44	44
6	L6	1a	DCE	24	40	82
7	L7	1a	DCE	24	45	80
8	L8	1a	DCE	24	62	92
9	L9	1a	DCE	24	47	33
10	L10	1a	DCE	24	52	31
11	L8	1a	DCM	24	70	94
12b	L8	1b	DCM	24	30	27
13c	L8	1c	DCM	48	80	90
14c	L8	1d	DCM	48	99	94
15c	L8	1e	DCM	48	78	94
16c	L8	1f	DCM	48	95	93
17c	L8	1g	DCM	48	93	93

DCE: 1,2-dichloroethane, DCM: dichloromethane, L: Ligand; N₃: high iodine azide reagent; 1a: azidobenziodoxolone, 1b: azidodimethylbenziodoxole; 1c–g: azidobenziodazolones.

^aReaction conditions: 2a (0.1 mmol), 1a (0.15 mmol), Cu(MeCN)₄PF₆ (10 mol%), L (12 mol %), solvent (2 mL), 25 °C; isolated yields; ee values were determined by HPLC analysis.

^b1b was used in place of 1a.

^cThe designated azidating reagent was used in place of 1a; 5 mol % of Cu(MeCN)₄PF₆ and 6 mol% of L8 were used instead.