Anuj Sharma

Herein, we report a water-controlled divergent mechanochemical sulfonylation of acetylenic carboxylic acids with sodium sulfinate salts. Under KI/TBHP-mediated ball-milling conditions, a low water content favors alkynyl sulfone formation, whereas excess water switches the reaction pathway to β-keto sulfones. The method accommodates aryl and alkyl sulfinate salts under transition-metal-, base-, and solvent-free conditions. Extension to α-methylstyrene substrates further demonstrates the broader applicability of this mechanochemical sulfonylation platform.

We report a mechanochemical CuCl-catalyzed three-component sulfonamidation using aryl radical precursors, K ₂ S ₂ O ₅ as a cheap and bench-stable SO ₂ surrogate, and N -benzoyloxyamines.

Herein, we report a mechanochemical-driven, nonphotochemical electron donor-acceptor (EDA)-complex strategy for the synthesis of thioethers via site-selective C-H functionalization using aryl (DMIX)iodonium salts (acceptor) and potassium thiolate salts (donor), providing a straightforward approach toward C-S bond formation under ball milling conditions. This protocol enables rapid access to thioethers via site-selective C-H functionalization from a wide range of aromatic and heteroaromatic substrates, including pharmaceutical derivatives, as well as diverse alkyl, aryl, and heteroaryl potassium thiolate salts, affording the desired products with excellent efficiency and regioselectivity. Mechanistic investigations indicated the formation of an EDA complex in the reaction medium and the involvement of a radical mechanistic pathway for the product formation. Overall, the dual combination of mechanochemistry with nonphotochemical EDA-complex activation provides a versatile platform for thioether synthesis with potential applications in medicinal chemistry and related areas.

Herein, we report a unified, photoinduced, solvent-controlled strategy for two distinct C-H functionalizations of azauracils: arylation in DMSO and oxyalkylation in THF via direct homolytic cleavage of the C-I bond of photoexcited aryl iodides. Mechanistic studies revealed a dual role of aryl iodides, serving as arylating agents in DMSO and hydrogen atom transfer (HAT) mediators with cyclic ethers, thus facilitating divergent C(sp²)-H and C(sp³)-H functionalizations. The protocol exhibited broad substrate compatibility and is amenable to scale-up and late-stage functionalization.

Herein, we report a calcium-mediated mechanochemical strategy for direct ketone synthesis from carboxylic acids and aryl iodides.

Herein, we disclose a photoinduced FeCl3-mediated ligand-to-metal charge transfer (LMCT) approach for the decarboxylative alkylation/cyclization of N-allyl and N-homoallyl aldehyde hydrazones. Readily available tertiary and challenging secondary aliphatic carboxylic acids...

A photocatalyst-free, visible-light-driven method enables S -aryl thioester synthesis from α-keto acids and aryl sulfinates via singlet-oxygen-mediated acyl radical generation and in situ thiosulfonate formation followed by SOMOphilic substitution.

Herein, we disclose the first example of stainless-steel-induced deoxygenative C-2 alkynylation of heterocyclic N-oxides under ball milling via a radical-mediated pathway. The current approach afforded the corresponding alkynylated quinolines/pyridines through alkynylation and deoxygenation in one step. Significant tolerance of structural variations with various electron-donating (-Me, -OMe, -Et, -ⁿBu, -OEt) and electron-withdrawing substituents (-I, -Br, -Cl, -F, -CF₃, -NO₂), both in the quinoline/pyridine N-oxides and in phenylacetylene derivatives, has been observed, affording 34 products in 61-94% yields. The method was successfully applied to the synthesis of two mGluR5 antagonists. Detailed mechanistic investigations based on extensive control experiments and XPS analysis corroborated the significant role of Fe(III) species present in the milling equipment (stainless steel) as well as the mechanical impact of the milling equipment (Fe/Zr-jar/balls) in facilitating the reaction via a radical pathway.

Herein, we describe a mechanochemical-assisted C-H alkylation of quinoxalinones and quinoline-N-oxides with Katritzky's salts. These salts are excellent alkyl precursors synthesized from alkyl amines. Our key finding is that these salts with moderate C-N bond dissociation energy generate alkyl radicals under mechanochemical stress. Mechanistic insights reveal that mechanical stress facilitates the homolytic scission of the C-N bond of Katritzky's salts, leading to the formation of an alkyl radical intermediate.