Abstract:
α,β-unsaturated compounds are crucial structural units for the synthesis of natural products, pharmaceuticals, and other useful materials. Herein, a green approach to prepare this kind of compounds has been developed through Meyer-Schuster rearrangement using an inexpensive, easy-preparation, environmentally benign and readily recycled silicon gel (SiO2) supported phosphomolybdic acid (PMA) as the catalyst.Under the condition of 1 mol% PMA/SiO2,and solvent as a DCE 25 or 50 ℃, a variety of second and tertiary propargylic alcohols are efficiently transformed into the corresponding α,β-unsaturated aldehydes, ketones or carboxylic esters in a good yield and a high stereo selectivity. The notable features of the method are mild reaction conditions, simple operation, and suitable for large-scale preparations.
