Construction of chiral α-tert-amine scaffolds via amine-catalyzed asymmetric Mannich reactions of alkyl-substituted ketimines

Stereoselective Mannich reactions of aldehydes with ketimines provide chiral β-amino aldehydes that bear an α-tert-amine moiety.

Divergent and Diastereoselective Synthesis of α-Monosubstituted and trans-α,β-Disubstituted γ-Lactams from (S)-N,N-Dibenzyl-α-amino Aldehydes via Henry and Michael Reactions

γ-Monosubstituted and trans-α,β-disubstituted γ-lactams were diastereoselectively synthesized from common intermediates (S)-N,N-dibenzylated aldehydes derived from natural l-(α)-amino acids, employing a divergent approach. The key features of the routes include diastereoselective Henry and Michael reactions that produced chiral γ-nitroester derivatives, which were subsequently submitted to a tandem reduction-lactamization sequence providing the title compounds. The versatility of routes can allow the preparation of several other mono-, di-, or tri-substituted γ-lactams.

Electrophilic Amination with Anthranils through Thioamide-Assisted Cobalt(III)-Catalyzed C(sp3)–H Activation

Cobalt(III)-catalyzed electrophilic amination of inert C(sp3)–H bonds of weakly coordinating thioamides with readily accessible anthranil derivatives was accomplished under mild conditions, with good functional group tolerance, thus providing various amino aldehydes and amino ketones. Moreover, our protocol with the versatile [Cp*Co(MeCN)3][SbF6]2 features excellent atom-economy and oxidant-free conditions, and allows facile late-stage functionalization.