An efficient heterogeneous catalyst (CuO@ARF) for on-water C-S coupling reaction: an application to the synthesis of phenothiazine structural scaffold

Organic and Medicinal Chemistry Letters

Table 2 CuO@ARF-catalyzed C-S cross-coupling reactions between haloarenes and thiol ^a

Entry	Aryl halide	Thiol	Time (h)	Product	Yield (%)^b
1	(4-H₃CO)C₆H₄I	C₆H₅SH	8	(4-H₃CO)H₄C₆ - S - C₆H₅	90
2	(3-H₃CO)C₆H₄I	(4-C1)C₆H₄SH	12	(3-H₃CO)H₄C₆ - S - C₆H₄(4-C1)	85
3	(2-H₃CO)C₆H₄I	(4-CH₃)C₆H₄SH	18	(2-H₃CO)H₄C₆ - S - C₆H₄(4-CH₃)	75
4	(3-NO₂)C₆H₄I	(4-CH₃)C₆H₄SH	11	(3-NO₂)H₄C₆ - S - C₆H₄(4-CH₃)	78
5	(4-H₃CO)C₆H₄I	(4-CH₃)C₆H₄SH	10	(4-H₃CO)H₄C₆ - S - C₆H₄(4′-CH₃)	75
6	(4-H₃C)C₆H₄Br	C₆H₅SH	24	No reaction	-
7	(4-CH₃CO)C₆H₄C1	C₆H₅SH	24	No reaction	-
8^c	(4-H₃C)C₆H₄Br	C₆H₅SH	24	No reaction	-
9	(5-Br)(2-H₃CO)C₆H₃I	C₆H₅SH	8	(5-Br)(2-H₃CO)H₃C₆ - S - C₆H₅	90
10	(3-Br)C₆H₄I	(4-CH₃)C₆H₄SH	16	(3-Br)H₄C₆ - S - C₆H₄(4-CH₃)	79
11	(3-C1)C₆H₄I	(4-CH₃)C₆H₄SH	16	(3-C1)H₄C₆ - S - C₆H₄(4-CH₃)	79
12	(4-H₃CO)C₆H₄I	(2,5-(CH₃)₂)C₆H₄SH	7	(4-H₃CO)H₄C₆ - S - C₆H₃(2,5-(CH₃)₂)	89
13	(4-H₃CO)C₆H₄I	CySH	16	(4-H₃CO)H₄C₆ - S - Cy	70
14	(4-H₃CO)C₆H₄I	n-C₅H₁₁SH	16	(4-H₃CO)H₄C₆ - S - C₅H₁₁-n	73
15	(3-H₃CO)C₆H₄I	n-C₇H₁₁SH	16	(4-H₃CO)H₄C₆ - S - C₇H₁₅-n	76
16^d	1,3-C₆H₄I₂	(4-CH₃)C₆H₄SH	14	1,3-((4-CH₃)C₆H₄S)₂ - C₆H₄	79
17	(2-Br)C₆H₄I	(2-NH₂)C₆H₄SH	8	(2-Br)H₄C₆ - S - C₆H₄(2-NH₂)	82

^aAryl halide: thiol: catalyst (1 mmol: 1.2 mmol: 200 mg), SDS (10 mol%), and K₂CO₃ (1.1 mmol) were taken in water (3 mL) and heated at 100°C. ^bYield refers to pure isolated products characterized by spectroscopic (¹H and ¹³C NMR) data. ^cCatalyst (300 mg mmol⁻¹ of aryl bromide), SDS (10 mol%), and Cs₂CO₃ (1.1 mmol). ^dAryl halide: thiol: catalyst (0.5 mmol: 1.2 mmol: 200 mg), SDS (10 mol%), and K₂CO₃ (1.1 mmol) were taken in water (3 mL).