HCID 68825497, compound → HCID 57754340, compound

Participants

Reaction Steps

A4a.1 (1.23 g, 5 mmol), bis-pinacolatodiborane (1.33 g, 5 mmol), potassium acetate (1.47 g, 15 mmol) and palladium acetate (224 mg, 1 mmol) were added to degassed DMF (anhydrous). The reaction mixture was heated at 80° C. overnight. The next day additional palladium acetate was added (610 mg, 2.5 mmol) was added and the reaction mixture heated overnight. The reaction mixture was cooled to room temperature and filtered through a pad of silica gel (washing with ethyl acetate). The filtrate was concentrated under reduced pressure with provided approximately 1.41 g of (S)—N-(1-(3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethyl)acetamide (LCMS (M+H)+=290.31). The product was dissolved in methanol and purified by reverse phase column chromatography (during which time the boronate ester underwent hydrolysis) to yield 875 mg (˜70%) of the chiral boronic acid. (M+H)+=208.17

Provenance & Evidence