2-(BENZOFURAN-2-YL)-4,4,5,5-TETRAMETHYL-1,3,2-DIOXABOROLANE

- Borylation of Aromatic Five-Membered Heterocycle According to the reaction scheme illustrated in Figure 2(a), a scintillation vial (with a magnetic stir bar) was charged with cobalt complex (0.01 mmol) selected from 1-4, 2 methylfuran (1 mmol) and pinacolborane (1 mmol). The reaction was monitored by the analysis of an aliquot of the mixture by GC-FID. The mixture was allowed to stir to completion at room temperature and was quenched by exposure to air. The resulting solid was solubilized in CDC1General procedure: In a glovebox filled with nitrogen, [Ir(OMe)(cod)]2 (33.1 mg, 0.050 mmol, 0.10 equiv), ICy·HCl(26.2 mg, 0.10 mmol, 0.20 equiv), NaOt-Bu (19.2 mg, 0.20 mmol, 0.40 equiv) andmethylcyclohexane (1.0 mL) were added to a 10 mL-sample vial with a Teflon-sealed screwcap, andstirred for 5 min at room temperature. A heteroarene (0.50 mmol, 1.0 equiv) and 1g (113.1 mg, 2.0equiv) were added, and then the cap was screwed on seal the vial. The vial was stirred at 110 °C for4 h. The reaction mixture was cooled to room temperature. Pinacol (236 mg, 2.0 mmol) in THF (2.0mL) was added and the reaction mixture was stirred under N2 at room temperature for 1.5 h. Thecrude mixture was filtered through a pad of Celite and eluted with EtOAc. The filtrate wasconcentrated in vacuo and sampled for analysis by 1HNMR spectroscopy using 1, 2-dichloroethaneas an internal standard. The residue was purified by flash column chromatography over silica geleluting with hexane/EtOAc. Product-containing fractions were concentrated in vacuo to give a pureborylated product.- Borylation of Aromatic Five-Membered Heterocycle According to the reaction scheme illustrated in Figure 2(a), a scintillation vial (with a magnetic stir bar) was charged with cobalt complex (0.01 mmol) selected from 1-4, 2 methylfuran (1 mmol) and pinacolborane (1 mmol). The reaction was monitored by the analysis of an aliquot of the mixture by GC-FID. The mixture was allowed to stir to completion at room temperature and was quenched by exposure to air. The resulting solid was solubilized in CDC13, 1 ] 3 passed through a plug of silica gel in a Pasteur pipette and then analyzed by H and C NMR spectroscopy without further purification. If desired, the foregoing reaction can also be administered in 2 ml of tetrahydrofuran (THF). Figure 2(a) provides conversion percentages for cobalt complexes 1-4 with values in parenthesis as isolated yields. Further, Figure 2(b) details additional borylation products achieved with Co complexes 2 and 3 according to the foregoing reaction parameters.

Molecular Weight:244.10
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:244.1270746
Monoisotopic Mass:244.1270746
Topological Polar Surface Area:31.6
Heavy Atom Count:18
Complexity:313
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes