Organic reactions with boronated alumina : I. the diels-alder reaction, II. amidolysis of esters

Boronated aluminas were used as Lewis acid catalysts in the Diels-Alder reaction of methyl acrylate and isoprene. The results were compared to the methyl acrylate and isoprene Diels-Alder reaction that is catalyzed by dissolved Lewis acids. The amidolysis reaction of methyl phenylacetate and aniline was carried out using bromo-boronated alumina as the Lewis acid catalyst. The complexes of B-bromo and B-chlorocatecholborane with crotonaldehyde were studied using proton NMR. The approximate conformation of the complexes were determined using rotating frame Overhauser enhancement spectroscopy (ROESY).