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Enantio- and diastereoselective conjugate borylation/Mannich cyclization
Egor M Larin1, Joachim Loup1, Iuliia Polishchuk1
1Davenport Laboratories, Department of Chemistry, University of Toronto 80 St. George St. Toronto Ontario M5S 3H6 Canada mark.lautens@utoronto.ca.
Abstract:
Strategies to capitalize on enolate intermediates generated from stereoselective conjugate borylation to α,β-unsaturated carbonyl systems are surprisingly rare despite the ubiquity of Michael acceptors, and the potential to generate valuable scaffolds bearing multiple stereocenters. Herein, we report a mild and stereoselective copper-catalyzed conjugate borylation/Mannich cyclization reaction. This strategy is feasible with a broad range of Michael acceptors, and can be leveraged to generate versatile borylated tetrahydroquinoline scaffolds bearing three contiguous stereocenters. The synthetic potential of these complex heterocycles has been explored through a series of derivatization studies.
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