A highly enantioselective and diastereoselective inverse electron demand hetero-Diels-Alder reaction between a variety of alpha,beta-unsatd. aldehydes and Et vinyl ether is described. The reaction is catalyzed by a chiral tridentate chromium(III) Schiff base complex, which is obtained by a concise and highly efficient protocol in two steps from com. materials. The resulting cycloadducts are isolated in good yields and are useful synthetic intermediates. [on SciFinder (R)]
Jérôme Waser, Stephanie Grace Elizabeth Amos
Alkynes are found in a multitude of natural or synthetic bioactive compounds. In addition to the capacity of these chemical motifs to impact the physicochemical properties of a molecule of interest, the well-established reactivity of alkynes makes them ...