Turkish Journal of Chemistry, Vol.43, No.2, 705-712, 2019
A microwave-assisted highly stereoselective one-pot Wittig reaction under solvent-free conditions
We report a novel microwave-assisted two-step, one-pot protocol for the synthesis of olefins (alkenes) via Wittig reaction. The reaction was carried out under solvent-free conditions using basic alumina both as a heterogeneous catalyst and a solid support. Varieties of aromatic aldehydes were converted into their corresponding olefins within 30-50 min 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 the end of the reaction, thereby adding another aspect to the greenness of the reaction.
Keywords:Wittig reaction;stereoselectivity;microwave-assisted;one-pot synthesis;heterogeneous catalysis