Direct enantioselective synthesis of bicyclic Diels-Alder products

The direct amine-catalyzed enantioselective Diels-Alder reaction between alpha,beta-unsaturated cyclic ketones and nitroolefins is presented. A simple diamine catalyzes the asymmetric Diels-Alder reaction with high stereoselectivity and furnishes the corresponding Diels-Alder adducts in good to high yields with > 25:1 dr and up to 86 % ee. The study demonstrates a convenient entry to functionalized bi-cyclic molecules contaning four stereocenters that are formed with excellent diastreoselectivity and good to high enantioselectivity.