Chemodivergent Sulfonylation of Enynones via Ionic and Radical Addition Modes of Sulfinic Acids

Solvent Controlled Chemodivergent Sulfonyl Addition into Enynones: Synthesis of α-Furyl Sulfones and Stereodefined Vinyl Sulfones

Sodium salt of aryl sulfinic acid reacts with enynone in a different manner, yielding α-furyl sulfone and stereodefined vinyl sulfone in toluene and EtOH respectively in the presence of ZnCl2. The salient features of this protocol include chemoselectivity, broad substrate scope, high efficiency, high yield, and easy purification. The synthetic utilities of the products are demonstrated by cycloaddition and cis-trans photoisomerization reactions.

Direct Synthesis of Sulfinylated Phenanthrenes via BF3-Promoted Annulation of 2-Alkynyl Biaryls with Arylsulfinic Acids

A novel approach to sulfinylated phenanthrenes has been developed by BF3-promoted annulation of 2-alkynyl biaryls with arylsulfinic acids. This approach utilizes readily available arylsulfinic acids as a sulfinyl source and affords a variety of sulfinylated phenanthrenes in good to excellent yields under simple and mild reaction conditions.

Divergent Reaction of Alkynes and TsCN: Synthesis of β-Sulfinyl Alkenylsulfones and (E)-Vinyl Sulfones

An efficient and high-selectivity approach for the divergent synthesis of β-sulfinyl alkenylsulfones and (E)-vinyl sulfones from alkynes and TsCN is described. A series of disulfurized products were constructed under mild conditions in the absence of transition metals. This transformation featured excellent regio- and stereoselectivity, good functional group compatibility, and broad substrate scope. The copper(I)-catalyzed sulfonation of alkynes with TsCN that affords (E)-vinyl sulfones in good to excellent yields was also developed.

Isocyanides inhibit bacterial pathogens by covalent targeting of essential metabolic enzymes

Isonitrile natural products, also known as isocyanides, demonstrate potent antimicrobial activities, yet our understanding of their molecular targets remains limited. Here, we focus on the so far neglected group of monoisonitriles to gain further insights into their antimicrobial mode of action (MoA). Screening a focused monoisonitrile library revealed a potent S. aureus growth inhibitor with a different MoA compared to previously described isonitrile antibiotics. Chemical proteomics via competitive cysteine reactivity profiling, uncovered covalent modifications of two essential metabolic enzymes involved in the fatty acid biosynthetic process (FabF) and the hexosamine pathway (GlmS) at their active site cysteines. In-depth studies with the recombinant enzymes demonstrated concentration-dependent labeling, covalent binding to the catalytic site and corresponding functional inhibition by the isocyanide. Thermal proteome profiling and full proteome studies of compound-treated S. aureus further highlighted the destabilization and dysregulation of proteins related to the targeted pathways. Cytotoxicity and the inhibition of cytochrome P450 enzymes require optimization of the hit molecule prior to therapeutic application. The here described novel, covalent isocyanide MoA highlights the versatility of the functional group, making it a useful tool and out-of-the-box starting point for the development of innovative antibiotics.

Photoredox-Catalyzed 1,4-Peroxidation-Sulfonylation of Enynones: A Three-Component Radical Coupling Approach for the Synthesis of Highly Functionalized Allenes

An Eosin Y-catalyzed visible light-promoted 1,4-peroxidation-sulfonylation of enynones was achieved to give tetrasubstituted allenes. The photoredox catalysis of Eosin Y allowed the concomitant formation of peroxy and sulfonyl radicals, where the preferential peroxy radical addition to the alkene moiety of enynones resulted in the subsequent α-keto radical-sulfonyl radical cross couplings. The developed photoredox catalysis of Eosin Y demonstrates a regioselective 1,4-diradical addition strategy, opening up a new possibility of diradical functionalization of conjugate systems.