461-82-5

407-14-7

461-82-5

General procedure: To a flame-dried 25 mL round-bottom flask were added activated magnesium chips (7.5 mmol, 1.5 eq.) and 5 mL of anhydrous tetrahydrofuran (THF). Two drops of 1,2-dibromoethane were added to the suspension to initiate the reaction. 5 min later, a solution of p-bromotrifluoromethoxybenzene (5 mmol, 1.0 eq.) dissolved in 5 mL of anhydrous THF was slowly added to the magnesium suspension at room temperature. A mild exothermic phenomenon was observed during the reaction. After determining the concentration of Grignard's reagent by titration, 1 mmol of the reagent was transferred to another flame-dried reaction flask. The solution was diluted with 3 mL of anhydrous toluene and after cooling to the preset temperature T, a solution of oxazepane (1.2 mmol, 1.2 equiv) dissolved in 1 mL of anhydrous toluene was added. The reaction mixture was held at temperature T for a reaction time t, followed by quenching the reaction with saturated aqueous ammonium chloride (NH4Cl). (Specific reaction temperatures and reaction times need to be listed according to the actual conditions of each substrate.)