Diastereodivergent Asymmetric Carboamination/Annulation of Cyclopropenes with Aminoalkenes by Chiral Lanthanum Catalysts.

Stereodivergent asymmetric catalysis is an important technology that can allow efficient access to various stereoisomers of a given product with multiple stereocenters from the same set of starting materials, but its application to the synthesis of a highly strained cyclopropane compound has remained unexplored to date. We report here the first diastereodivergent enantioselective synthesis of bicyclic aminocyclopropanes by lanthanum-catalyzed asymmetric carboamination/annulation of cyclopropenes with aminoalkenes. This protocol features 100% atom efficiency, good yield (up to 90%), and high chemo- (up to >20:1) and stereoselectivity (up to >20:1 dr and 99% ee), constituting a unique route for the efficient synthesis of two different diastereoisomers of a given chiral bicyclic aminocyclopropane compound.