Table 1. Optimization of the reaction condition^ab.

Entry	AD	Oxidant	Solvent	T (°C)	Yield (%)
1	—	TBHP	PhCl	120	0
2	I2	TBHP	PhCl	120	9
3	HI	TBHP	PhCl	120	21
4	NaI	TBHP	PhCl	120	17
5	KI	TBHP	PhCl	120	11
6	NaIO4	TBHP	PhCl	120	59
7	CuI	TBHP	PhCl	120	27
8	AgI	TBHP	PhCl	120	8
9	FeI2	TBHP	PhCl	120	33
10	ZnI2	TBHP	PhCl	120	34
11	NaIO4	DTBP	PhCl	120	7
12	NaIO4	H2O2	PhCl	120	5
13	NaIO4	TBHP	Dioxane	120	18
14	NaIO4	TBHP	Toluene	120	37
15	NaIO4	TBHP	TBAC	120	54
16	NaIO4	TBHP	DMSO	120	21
17	NaIO4	TBHP	DMF	120	25
18	NaIO4	TBHP	Toluene + PhCl	120	45
19	NaIO4	TBHP	PhCl	100	19
20	NaIO4	TBHP	PhCl	110	36
21	NaIO4	TBHP	PhCl	130	48
22	NaIO4	TBHP	PhCl	120	62c, 70d, 65e
23	NaIO4	TBHP	PhCl	120	42g, 18h

^aReaction conditions: 1a (0.5 mmol), 2a (1.5 mmol), additive (20 mol%), oxidant (1.5 mmol), solvent (4 mL), 12 h, temperature 100–130 °C in sealed tube.

^bYield of isolated product based on 1a.

^c30 mol% additive was used.

^d40 mol% additive was used.

^e50 mol% additive was used.

^g1 mmol of 2a.

^h0.5 mmol of 2a was added.