Table 6. Optimization of the Pd(ii)/silver foil-catalyzed mechanochemical Sonogashira reaction ^a .

Entry	X	R1	R2	Product	Yield b (%)
1	I	4-(Cl)Ph	Ph	51	90
2	I	4-(Br)Ph	Ph	52	88
3	I	4-(F)Ph	Ph	53	87
4	Br	4-(F)Ph	Ph	53	80
5	I	4-(CH2CH3)Ph	Ph	54	93
6	Br	4-(CH2CH3)Ph	Ph	54	95
7	Br	4-(C(CH3)3)Ph	Ph	55	90
8	Br	4-(CH3)Ph	Ph	56	90
9	I	4-(CH3)Ph	Ph	56	95
10	I	4-(Cl)Ph	CH2CH2CH2CH3	57	92
11	I	4-(Br)Ph	CH2CH2CH2CH3	58	88
12	I	4-(F)Ph	CH2CH2CH2CH3	59	90
13	I	4-(CH3)Ph	CH2CH2CH2CH3	60	93
14	Br	4-(CH3)Ph	CH2CH2CH2CH3	60	93
15	Br	4-(C(CH3)3Ph	CH2CH2CH2CH3	61	93
16	I	Ph	4-(Cl)Ph	51	85
17	Br	Ph	4-(Cl)Ph	51	77
18	I	Ph	4-(Br)Ph	52	88
19	Br	Ph	4-(Br)Ph	52	80
20	I	Ph	4-(F)Ph	53	89
21	I	Ph	4-(CH2CH3)Ph	54	93
22	Br	Ph	4-(CH2CH3)Ph	54	86
23	I	Ph	4-(CH3)Ph	56	95
24	Br	Ph	4-(CH3)Ph	56	85
25	I	Ph	CH2CH2Ph	62	83
26	I	4-(Cl)Ph	CH2CH2Ph	63	80
27	Br	4-(CH3)Ph	CH2CH2Ph	64	85

^aReaction conditions: halide (1.05 mmol), alkyne (1.00 mmol), base (1.5 mmol), Pd catalyst and silver foil added to a SPEX 8000M mixer/mill (18 Hz) for h.

^bGC yields.