Intermolecular difunctionalization of alkenes: synthesis of β-hydroxy sulfides

Tuning Selectivity in the Visible-Light-Promoted Coupling of Thiols with Alkenes by EDA vs TOCO Complex Formation

The visible-light-promoted catalyst-free condition has been demonstrated for self- and cross-coupling reactions of thiols in an ambient atmosphere. Further, synthesis of β-hydroxysulfides is accomplished under very mild conditions involving the formation of an electron donor-acceptor (EDA) complex between a disulfide and an alkene. However, the direct reaction of thiol with alkene via the formation of a thiol-oxygen co-oxidation (TOCO) complex failed to produce the desired compounds in high yields. The protocol was successful with several aryl and alkyl thiols for the formation of disulfides. However, the formation of β-hydroxysulfides required an aromatic unit on the disulfide fragment, which supports the formation of the EDA complex during the course of the reaction. The approaches presented in this paper for the coupling reaction of thiols and the synthesis of β-hydroxysulfides are unique and do not require toxic organic or metal catalysts.

Aryl fluorosulfates: powerful and versatile partners in cross-coupling reactions

Aryl fluorosulfates are versatile building blocks in organic synthesis and have gained increasing attention in SuFEx (Sulfur Fluoride Exchange) click chemistry. They are easily and conveniently prepared from phenols using sulfuryl fluoride SO₂F₂ as a low-cost sulfonyl fluoride provider. Recently, they served as less toxic and more atom economical alternatives to triflates in an impressive number of carbon-carbon and carbon-heteroatom cross-coupling reactions. In this review, we summarize the current advances and developments in applying aryl fluorosulfates as electrophilic partners in cross-coupling reactions.

Three-Component Oxychalcogenation of Alkenes under Metal-Free Conditions: A Tetrabutylammonium Tribromide-Catalyzed System

A three-component oxychalcogenation reaction, from alkenes, diselenides/thiophenols, and H₂O/alcohols, has been realized herein. Tetrabutylammonium tribromide (TBATB) and dimethylsulfoxide (DMSO) are utilized as the catalyst and the terminal oxidant, respectively, to enable this difunctionalization transformation. The metal-free reaction system shows good functional group compatibility, providing a unified and practical approach to access β-hydroxyl or β-alkoxy organochalcogenides.

A Convenient Synthesis towards 2-Bromo-2-(methoxy(phenyl)methyl)malononitrile and 2-Iodo-2-(methoxy(phenyl)methyl)malononitrile

This short note elaborates a concise protocol for the synthesis of two novel vicinal haloethers bearing a malonontrile group, 2-bromo-2-(methoxy(phenyl)methyl)malononitrile (1) and 2-iodo-2-(methoxy(phenyl)methyl)malononitrile (2). The structures of the synthesized compounds were confirmed by 1H, 13C-NMR spectroscopy. The final products indicate that methanol not only acts as solvent but also participates in and dominates the reaction result.

External oxidant-free and selective thiofunctionalization of alkenes enabled by photoredox-neutral catalysis

A photoredox approach was reported to realize a highly selective three-component thiohydroxylation, thioalkoxylation and thioamination of vinylarenes towards valuable vicinal S,O- and S,N-disubstituted molecules under mild conditions.

Direct selenosulfonylation of unsaturated compounds: a review

In this review, we have discussed recent developments on the direct selenosulfonylation of unsaturated compounds which lead to the formation of two new carbon-sulfur and carbon-selenium bonds in a single operation. The reactions were classified based on the type of starting unsaturated compound and product. Thus, the review is divided into three major sections. The first describes the current literature on selenosulfonylation of alkenes. The second section covers the available literature on selenosulfonylation of alkynes. The third focuses exclusively on selenosulfonylation of allenes.

In this review, we have discussed recent developments on the direct selenosulfonylation of unsaturated compounds which lead to the formation of two new carbon-sulfur and carbon-selenium bonds in a single operation.

Alkoxysulfenylation of alkenes: development and recent advances

Among the wide variety of synthetic transformations of inexpensive and abundant feedstock alkenes, vicinal difunctionalization of carbon-carbon double bonds represent one of the most powerful and effective strategies for the introduction of two distinct functional groups into target compounds in a one-pot process. In this context, the direct alkoxysulfenylation of alkenes has emerged as an elegant method to construct valuable β-alkoxy sulfides in an atom- and pot-economic manner utilizing readily accessible starting materials. Here, we review the available literature on this appealing research topic by hoping that it will be beneficial for eliciting further research and thinking in this domain.

Direct synthesis of sulfenamides, sulfinamides, and sulfonamides from thiols and amines

Needless to say that organosulfur compounds with sulfur–nitrogen bonds have found various applications in diverse fields such as pharmaceuticals, agrochemicals, polymers, and so forth. Three major groups of such compounds are sulfenamides, sulfinamides, and sulfonamides which have been widely applied as building blocks in medical chemistry. Owing to their significant role in drug design and discovery programs, the search for and development of efficient, environmentally friendly, and economic processes for the preparation of the title compounds is of great importance in the pharmaceutical industry. Recently, oxidative coupling of thiols and amines, two readily available low-cost commodity chemicals, has emerged as a highly useful method for synthesizing structurally diverse sulfenamides, sulfinamides, and sulfonamides in a single step. Since this strategy does not require additional pre-functionalization and de-functionalization steps, it considerably streamlines synthetic routes and substantially reduces waste generation. This review will focus on recent advances and achievements in this attractive research arena.

This review provides a concise overview of the synthesis of biologically and synthetically valuable sulfenamide, sulfinamide, and sulfonamide derivatives through the direct oxidative coupling of readily available low-cost thiols and amines.

Light-Promoted and Tertiary-Amine-Assisted Hydroxysulfenylation of Alkenes: Selective and Direct One-Pot Synthesis of β-Hydroxysulfides

A light-promoted and tertiary-amine-assisted strategy for efficient hydroxysulfenylation of both electron-rich and electron-deficient alkenes with thiophenols to selectively and directly access β-hydroxysulfides in one pot is described herein. In contrast to the previously reported thiol-oxygen co-oxidation reactions, this simple and sustainable approach features mild reaction conditions, high efficiency, and excellent functional group tolerance.

Amphetamine Drug Detection with Inorganic MgO Nanotube Based on the DFT Calculations

In this study, the main challenge was to focus on the detection of amphetamine (AN) using a type of magnesium oxide nanotube (MgONT) sensor through density functional theory (DFT) calculations. Nowadays, due to the adverse effects of drug abuse, governments put all their efforts into detecting and managing illegal drugs such as AN. Therefore, the detection of AN in biological specimens is of great importance. In this study, through DFT calculations, the intrinsic sensing properties of MgONT were investigated for the detection of AN. We concluded that the MgONT considerably enhances the reactivity of the MgONT toward AN. Furthermore, the sensing response for the MgONT was 392.36. The results showed that there was a considerable change in the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and there was a drop in the band gap value (E_g). This decrease in the E_g value improved the electrical conductivity. Moreover, desorption of AN from the surface of the MgONT had a slight recovery time (~ 22.89 ms). This work illustrated that MgONT could be considered a proper candidate for electronic sensing and AN drug delivery in biological systems.

The adsorption of cathinone drug on the platinum decorated silicon carbide nanosheets: DFT studies

Cathinone (CTN), classified as stimulants, is one of the psychoactive drugs. Although the sale of CTN was controlled by international drug laws, it was still sold on the internet, and its overdose caused many deaths worldwide. As chemical sensors, two-dimensional (2D) nanomaterials have drawn attention to be used in various biological molecules. In the current study, the sensing characteristics of the intrinsic SiC monolayer (SiCM) and its Pt-decorated state (Pt@SiCM) were scrutinized toward the CTN drug by utilizing density functional theory (DFT) calculations. It was illustrated that the SiCM sensing response to CTN is insignificant (~ 10.6 at 298 K) due to the weak interaction with the adsorption energy of -0.25 eV. After the decoration of Pt on the SiCM, it was adsorbed above a hexagonal ring, which formed an η⁶-Pt half-sandwich and the adsorption energy was -3.62 eV. It was found that the Pt@SiCM strongly adsorbed CTN and the adsorption energy was -1.60 eV. Therefore, Pt-decoration augmented the SiCM sensing response to CTN from 10.3 to 716.6. The recovery time obtained for the CTN desorption from the Pt@SiCM surface was 12.7 s, which was short. It was concluded that Pt-decoration makes the SiCM a favorable candidate for CTN identification.

Recent trends in dehydroxylative trifluoro-methylation, -methoxylation, -methylthiolation, and -methylselenylation of alcohols

This review studies on the direct dehydroxylative trifluoromethylation, trifluoromethoxylation, trifluoromethylthiolation, and trifluoromethylselenylation of alcohols.