Asymmetric Aza-Mannich Reactions of Sulfinimines:  Scope and Application to the Total Synthesis of a Bromopyrrole Alkaloid

Abstract

[reaction: see text] An asymmetric intermolecular aza variant of the Mannich reaction is reported utilizing chiral sulfinimine anions as the nucleophile and N-sulfonyl aldimines as the electrophilic component. A wide range of nucleophiles and electrophiles are tolerated by the reaction conditions, delivering the condensation products in good to excellent yield with a high degree of stereocontrol. Application of this methodology to the total synthesis of a natural product is reported.

Synthetic approaches towards alkaloids bearing α-tertiary amines

“…355 Several other synthetic approaches toward these molecules have been reported. These strategies for the installation of the ATA moiety involve diastereoselective nitrene insertion, 352 1,3dipolar cycloaddition, 356,357 Hofmann rearrangement, 358 diastereoselective iodocyclization, 359,360 Grignard addition to an imine 361 and a variety of other methods. [362][363][364][365][366] Indeed, manzacidines remain targets of great interest for synthetic chemists.…”

Indium‐Promoted Diastereo‐ and Regioselective Propargylation of Chiral Sulfinylimines

“…Yields are given in Scheme . Imines 3a ,14 3b ,15 3c ,16 3d ,15 3e ,15 3h ,17 3i ,18 3j ,19 3k ,20 3m ,21 3n ,15 and 3o 22 were characterized by comparison of their physical and spectroscopic data with those reported in the literature. The corresponding physical, spectroscopic, and analytical data for imines 3f , 3g ,and 3l follow.…”

Diastereodivergent Henry Reaction for the Stereoselective Construction of Nitrogen‐Containing Tetrasubstituted Carbons: Application to Total Synthesis of Manzacidins A and C

“…In our studies on the development of new efficient methods for the stereoselective construction of tetrasubstituted carbons bearing a nitrogen functional group, we focused on the synthesis of manzacidins A and C. These compounds have attracted significant attention with regard to new synthetic methods for the stereoselective construction of β,β‐disubstituted β‐amino alcohol structures . Various methods have been previously developed, including asymmetric Strecker synthesis, C−H insertion of nitrene, asymmetric aza‐Mannich, asymmetric 1,3‐dipolar cycloaddition, asymmetric Michael addition, allyl cyanate‐to‐isocyanate [3,3] sigmatropic rearrangement, iodocyclization of isothiourea, asymmetric hydrogenation, and decarbonylative radical coupling …”