Asymmetric Hydroazidation of Nitroalkenes Promoted by a Secondary Amine-Thiourea Catalyst
Chiral β-nitro azides are obtained by asymmetric addition of azides to nitroalkenes, with an enantioselectivity of up to 82% ee. The reaction, promoted by an easily accessible secondary amine-thiourea catalyst, is performed with azidotrimethylsilane in th
Bellavista, Tiziana,Meninno, Sara,Lattanzi, Alessandra,Della Sala, Giorgio
Asymmetric synthesis of trisubstituted tetrahydrothiophenes bearing a quaternary stereocenter via double michael reaction involving dynamic kinetic resolution
The stereoselective synthesis of highly functionalized tetrahydrothiophenes bearing three contiguous stereocenters, one of them quaternary, can be achieved by reacting trans-α-cyano-α,β-unsaturated ketones and trans-tert-butyl 4-mercapto-2-butenoate in the presence of a readily available amine thiourea. The products are obtained in high yield, good diastereoselectivity, and excellent enantioselectivity. The overall formation of tetrahydrothiophenes occurs via a cascade double Michael reaction involving a highly efficient process of dynamic kinetic resolution.