Table 1.

Optimization of reaction conditions ^a.

Entry	Base	Solvent	Temperature (°C)	Yield (%) b
1	TEA	MeCN	45	48
2	K2CO3	MeCN	45	32
3	Cs2CO3	MeCN	45	69
4	DIPEA	MeCN	45	81
5	DIPEA	THF	45	12
6	DIPEA	DMF	45	23
7	DIPEA	CH2Cl2	45	7
8	DIPEA	MeCN	45	76 c
9	DIPEA	MeCN	25	68
10	DIPEA	MeCN	65	55
11	DIPEA	MeCN	45	79 d
12	DIPEA	MeCN	45	71 e
13	DIPEA	MeCN	45	81 f
14	DIPEA	MeCN	45	70 g

^a Conditions: 1a (0.5 mmol), HCCP (1.1 equiv.), base (5.0 equiv.), solvent (5 mL), rt, activation time (1 h), then thiophenol (6.0 equiv.), 45 °C, 23 h; ^b Isolated yield; ^c HCCP (1.0 equiv.); ^d Thiophenol (5.0 equiv.); ^e Thiophenol (4.0 equiv.); ^f DIPEA (6.0 equiv.); ^g DIPEA (4.0 equiv.).