. Author manuscript; available in PMC: 2011 Jul 4.

Published in final edited form as: J Am Chem Soc. 2011 Mar 30;133(16):6403–6410. doi: 10.1021/ja200792m

Table 2.

Cu-Catalyzed Desulfitative Coupling using a “Metallothionein Mimic”


entry	R¹	R²	ketone (%)
Boronic Acid Couplings using 1.2 equiv of R²B(OH)₂^a
1	p-tolyl	4-chlorophenyl	91
2	p-tolyl	4-cyanophenyl	88
3	p-tolyl	4-(methoxycarbonyl)phenyl	86
4	p-tolyl	4-(formyl)phenyl	80
5	p-tolyl	3-acetylphenyl	71
6	p-tolyl	3-formylphenyl	69
7	p-tolyl	3-hydroxyphenyl	70
8	p-tolyl	2,5-dimethoxyphenyl	68
9	p-tolyl	trans-2-(4-chlorophenyl)vinyl	52
10	n-propyl	4-(methoxycarbonyl)phenyl	82
11	CH₂OAc	3-furyl	73
12	CH₂OAc	4-(methoxycarbonyl)phenyl	78
13	(E)-1-propenyl	4-methoxyphenyl	80

Organostannane Couplings using 1.1 equiv of R²SnBu₃^b
14	p-tolyl	4-methoxyphenyl	95
15	p-tolyl	4-fluoro-3-methylphenyl	81
16	p-tolyl	4-iodophenyl	68
17	thienyl	4-methoxyphenyl	86
18	n-propyl	2-methoxypyridin-2-yl	70
19	Cyclohexyl	4-methoxyphenyl	62

Typical experimental procedure: A dry microwave tube (10 mL) was equipped with a magnetic stir bar. To the tube was added the corresponding thiol ester (0.1 mmol), boronic acid (0.12 mmol) and CuMeSal (0.02 mmol). The reaction tube was flushed with argon and sealed. Through the septum anhydrous and degassed DMF (1 mL) was added. The mixture was subsequently heated in a microwave reactor at 150 °C for 1 h. After cooling, ethyl ether (10 mL) was added to the mixture. The reaction mixture was washed with water (2×5 mL), brine (5 mL), dried over MgSO₄ and evaporated. The residue was purified by preparative plate silica chromatography using hexanes/EtOAc as the eluent.

Typical experimental procedure: A dry microwave tube (10 mL) was equipped with a magnetic stir bar. To the tube were added the corresponding thiol ester (0.1 mmol) and CuMeSal (0.02 mmol). The reaction vessel was flushed with argon and sealed. Through the septum the organostanane (0.11 mmol) dissolved in anhydrous and degassed DMF (1 mL) was added. The mixture was subsequently heated in a microwave reactor at 150 °C for 1 h. After cooling, ethyl ether (10 mL) was added to the mixture. The reaction mixture was washed with water, brine, dried over MgSO₄ and evaporated. The residue was purified by preparative plate silica chromatography using hexanes/EtOAc as the eluent.