A microwave-assisted highly stereoselective one-pot Wittig reaction under solvent-free conditions

Abstract

We report a novel microwave-assisted two-step, one-pot protocol for the synthesis of olefins (alkenes) viaWittig reaction. The reaction was carried out under solvent-free conditions using basic alumina both as a heterogeneouscatalyst and a solid support. Varieties of aromatic aldehydes were converted into their corresponding olefins within 30–50min with good to excellent yields. An excellent predominance of E -isomers over Z -isomers (up to 100% E-selectivity)for all the olefin products was observed. This showed the attractive stereocontrol of our reported protocol. In addition,owing to the solid-state nature of the reactions, our procedure prevented the need for tedious aqueous extraction at theend of the reaction, thereby adding another aspect to the greenness of the reaction.