To a solution of [RhCl(COD)]2 (63 mg, 0.031 mmol) in dioxane (10 mL) was added aqueous KOH (1.5M, 8.29 mmol, 5.53 mL), followed by (3-bromophenyl)boronic acid (1.67 g, 8.29 mmol). Then a solution of the tert-butyl 3-(2-ethoxy-2-oxoethylidene)azetidine-1-carboxylate in dioxane (7.5 mL) was added. The reaction mixture was microwaved at 100° C. for 5 min at 300 W. Brine was added and the mixture was extracted twice with ethyl acetate. The combined organics were washed with brine and then dried (MgSO4), filtered and concentrated. Purification by column chromatography (4/1 Pet ether/ethyl acetate) gave the Michael adduct (1.31 g, 79%) as a light yellow oil.
