Compound 1
chloro(4-methoxypyridine)bis(dimethylglyoximato)cobalt(III)
From: Catalytic dehydrogenative decarboxyolefination of carboxylic acids
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Compound data: 1H NMR
Compound data: 13C NMR
Compound data: Crystallographic data
Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.
In air, to a 100-mL round-bottom flask charged with CoCl2 (1.3 g, 10 mmol, 1.0 equiv.) and acetone (50 mL) was added dimethylglyoxime (2.6 g, 22 mmol, 2.2 equiv.). A gentle stream of air was passed through the solution via a needle. After 30 minutes (during which time, acetone was added to compensate for evaporation), the reaction flask was placed on ice for 20 minutes. The resulting green crystals were collected by filtration over a Büchner funnel. The collected crystals were rinsed with cold acetone (5 mL) and further dried at room temperature under vacuum to afford 3.0 g of a green solid. In air, a portion of the green solid (1.1 g) was suspended in methanol (30 mL) in a 100-mL round-bottom flask. To the mixture was added 4-methoxypyridine (720 mg, 670 µL, 6.60 mmol). The suspension was stirred until the green solid was visibly converted to a brown crystalline solid (approximately 30 minutes), then water (50 mL) was added to the reaction mixture. The flask was then placed on ice for 10 minutes. Crystals were collected by filtration over a Büchner funnel, rinsed with water/methanol 2:1 (v/v) (3 × 10 mL) followed by diethyl ether (2 × 10 mL) and then dried at room temperature under vacuum to afford Co(dmgH)2(4-OMe-py)Cl (1) 1.1 g (71% yield over two steps) as a brown solid. NMR Spectroscopy: 1H NMR (500 MHz, CDCl3, 23 ºC, δ): 8.02–7.96 (m, 2H), 6.74–6.67 (m, 2H), 3.81 (s, 3H), 2.40 (s, 12H). 13C NMR (125 MHz, CDCl3, 23 ºC, δ): 167.7, 152.8, 151.7, 112.2, 56.1, 13.2. HRMS-ESI(m/z) calc’d for C14H21N5O5ClCoNa+ [M+Na]+, 456.0455; found, 456.0459.