Electrochemical Decarbonylative Aminosulfonylation of Alkynes with Sulfinates and N-(Formyl)anilides

Sc(OTf)3-Catalyzed Diastereoselective Hydroxyheteroarylation of C-C σ-Bonds of Bicyclo[1.1.0]butanes with Azaheterocyclic N-Oxides

A mild and atom-economical reaction for the Sc(OTf)3-catalyzed 1,3-hydroxyheteroarylation of bicyclo[1.1.0]butanes (BCBs) with azaaryl N-oxides via an unprecedented [4π+2σ] cycloaddition/ring-opening process is described. This transformation provides a novel strategy for the highly regio- and diastereoselective preparation of azaheterocycle-tethered 1,1,3,3-tetrasubstituted cyclobutane derivatives and offers a broad substrate scope and high yields.

Electrochemical Synthesis of 3-(Sulfonyl)quinol-4-ones from o-Alkynyl-N-(formyl)anilides and Sulfinates

Electrolysis of o-alkynyl-N-(formyl)anilides and sodium sulfinates on graphite electrodes delivers biologically sound 3-(sulfonyl)quinol-4-ones with moderate to good yields. The reaction is carried out in an undivided cell in the presence of silver(I) oxide with potassium iodide or sodium tetrafluoroborate as the supporting electrolyte. The reaction tolerates variously substituted anilides as well as aryl and alkyl sulfinates. The transformation proceeds as a domino sequence of oxysulfonylation and cyclocondensation steps.

Regio- and Stereoselective β-Sulfonylamination of Alkynes via Photosensitized Bifunctional N-S Bond Homolysis

Nitrogen central radicals (NCRs) are versatile synthetic intermediates for creating functional nitrogen-containing molecules. Herein, a photosensitized β-sulfonylamination of terminal alkynes as well as acetylene has been established by employing N-sulfonyl heteroaromatics as bifunctional reagents (BFRs) to efficiently deliver versatile (E)-β-sulfonylvinylamines with excellent regio- and stereoselectivities. Mechanistic studies suggest a base-accelerated energy transfer (EnT) photocatalysis involving aromatic NCR formation, radical addition to alkynes, and sulfonylation processes.

Photocatalyst-free, visible-light-induced regio- and stereoselective synthesis of phosphorylated enamines from N-allenamides via [1,3]-sulfonyl shift at room temperature

Herein, we report the first visible-light-induced strategy for the rapid synthesis of densely functionalized α- and γ-phosphorylated β-sulfonyl enamines in a regio- and stereoselective manner from N-sulfonyl allenamides and H-phosphine oxides. The transformation displays a broad substrate scope, while operating at room temperature under photocatalyst- and additive-free conditions. In this atom-economical process, either terminal or substituted N-sulfonyl allenamides trigger an unprecedented N-to-C [1,3]-sulfonyl shift, relying on a dual radical allyl resonance and α-heteroatom effect in its triplet excited state. A plausible reaction mechanism is proposed which was supported by the outcomes of theoretical approaches based on Density Functional Theory (DFT) calculations.

Electrochemical Sulfonylation/Cyclization of N-Alkenylacrylamides with Sodium Sulfinates or Sulfonyl Hydrazides

Two general protocols for the regioselective electrochemically enabled sulfonylation cyclization of N-alkenylacrylamides with sodium sulfinates or sulfonyl hydrazides were described. These methods were carried out under mild, chemical oxidant-free, and transition-metal-free conditions with a broad substrate scope and good functional group tolerance to provide sulfonyl-containing 4-pyrrolin-2-ones, which is readily scalable to the gram scale.

Visible-light-induced photocatalyst-free cascade cyclization of 3-(2-(ethynyl)phenyl)quinazolinones to sulfonated quinolino[2,1-b]quinazolinones

A visible-light-induced K2S2O8-promoted cascade sulfonation/cyclization reaction was established using 3-(2-(ethynyl)phenyl)quinazolinones as efficient substrates under mild conditions. A series of sulfonated quinolino[2,1-b]quinazolinones were successfully synthesized under transition-metal- and photocatalyst-free conditions. Notably, this strategy has the advantages of room temperature and simple operation, easy scale-up, and good functional group tolerance.

Regio- and Stereoselective Intermolecular 1,2-Difunctionalization of Terminal Alkynes: An Approach to Access (Z)-β-Amidovinylsulfones

We have developed the first I2/base-catalyzed regio- and stereoselective intermolecular β-amidosulfonylation of terminal alkynes using sodium sulfinates and quinoxalinone derivatives. The present methodology is compatible with a broad spectrum of various heterocyclic amides, terminal alkynes, and sodium sulfinates. It provides rapid access to valuable (Z)-β-amidovinyl sulfones at mild conditions. Moreover, the synthetic application of this methodology was demonstrated by the late-stage functionalization of numerous bioactive molecules.

Electrochemical C(sp2)-H/N-H "formal" cross-dehydrogenative coupling of olefins with benzotriazoles for synthesis of N-vinyl benzotriazoles

The paper details an electrochemical method that couples olefins with benzotriazoles to form C(sp2)-N bonds, enabling the synthesis of N-vinyl benzotriazoles in moderate to good yields. nBu4NI functions as both an electrolyte and an iodine mediator, and the method does not require oxidants or metals. It is a highly atom-economical and clean reaction, with hydrogen as the sole byproduct.