Effect of Aqueous Polyethylene Glycol on 1,3-Dipolar Cycloaddition of Benzoylnitromethane/Ethyl 2-Nitroacetate with Dipolarophiles: Green Synthesis of Isoxazoles and Isoxazolines

A 1:1 mixture of water-polyethylene glycol (PEG) facilitated the 1,3-dipolar cycloaddition of benzoylnitromethane/ethyl 2-nitroacetate with terminal alkynes or alkenes leading to isoxazoles or isoxazolines under green conditions. The methodology is free from the use of any base, catalyst, dehydrating agent or hazardous solvent.