One-Pot Synthesis of Chiral Succinate Dehydrogenase Inhibitors and Antifungal Activity Studies

In this work, a series of novel chiral succinate dehydrogenase inhibitors (SDHIs) are synthesized through a one-pot Rh-catalyzed asymmetric hydrogenation-condensation strategy. This method exhibits high efficiency (up to 1000 Ton, 94% yield over two steps), high stereoselectivity (up to 99% ee), and broad substrate scope (68 examples in total), providing a superior pathway for the synthesis of such chiral fungicides. Mechanistic studies indicate that the amino group at the 2-position of the phenyl ring acts as an activating group, enhancing the reactivity and stereoselectivity control of the reaction. Furthermore, these molecules exhibit broad-spectrum and highly effective antifungal biological activity. Notably, enantiomers show significant differences in both in vitro and in vivo fungi-inhibiting experiments. Especially, (S)-5f showcases an antifungal activity against Botrytis cinerea (EC50 = 0.48 µm) that is much higher than that of its R enantiomer (EC50 = 36.7 µm). Molecular docking calculations, molecular dynamic simulation, enzyme activity assays, and ligand-target interaction experiments demonstrate that (S)-5f (ΔGMM-PBSA = -18.86 kcal mol-1, KD = 6.04 µm) inhibits succinate dehydrogenase more effectively than its R enantiomer (ΔGMM-PBSA = -13.01 kcal mol-1, KD = 8.5 µm). Moreover, the two enantiomers have significantly different effects on spore germination and the destruction of fungal phenotype.

Recent Advances in the Enantioselective Synthesis of Chiral Amines via Transition Metal-Catalyzed Asymmetric Hydrogenation

Chiral amines are key structural motifs present in a wide variety of natural products, drugs, and other biologically active compounds. During the past decade, significant advances have been made with respect to the enantioselective synthesis of chiral amines, many of them based on catalytic asymmetric hydrogenation (AH). The present review covers the use of AH in the synthesis of chiral amines bearing a stereogenic center either in the α, β, or γ position with respect to the nitrogen atom, reported from 2010 to 2020. Therefore, we provide an overview of the recent advances in the AH of imines, enamides, enamines, allyl amines, and N-heteroaromatic compounds.

Generation of (E)-β-sulfonyl enamines from sulfur dioxide via a radical process

An iron(ii)-catalyzed three-component reaction of O-acyl oximes, sulfur dioxide, and N-vinylacetamides is accomplished. Diverse (E)-β-sulfonyl enamines are obtained in moderate to good yields by using this protocol with excellent stereoselectivity and regioselectivity.

Bismuth(III)-Catalyzed Sequential Enamine-Imine Tautomerism/2-Aza-Cope Rearrangement of Stable β-Enaminophosphonates: One-Pot Synthesis of β-Aminophosphonates

A novel catalytic tautomeric transformation of a β-enaminophosphoryl and 2-aza-Cope rearrangement sequence has been successfully applied to the one-pot synthesis of β-aminophosphonates with high efficiency and good tolerance. In this tandem reaction, Bi(OTf)₃ exhibits unique activities and promotes both of enamine-imine tautomerism and 2-aza-Cope rearrangement.