Iodine mediated direct coupling of benzylic alcohols with dithiocarbamate anions: An easy access of S-benzyl dithiocarbamate esters under neat reaction condition

Disulfide-mediated ruthenium-catalyzed direct C-H thiolation in benzoxazinone systems: selective synthesis of ortho-thiolated 2-arylbenzoxazinones

2-Arylbenzoxazinone undergoes direct ortho-C-H thiolation by using diaryl disulfide in the presence of a Ru(II)-phosphine catalytic system and an Ag additive. The protocol has been generalized with benzoxazinone substrates having different substituents and a series of disulfides. ortho-Selenylation has also been performed successfully using diphenyl diselenide under similar catalytic conditions. Based on control experiments and reported literature studies, a probable mechanistic pathway has been suggested.

Dithiocarbamate as a Carbonyl Alternative in Pd-Catalyzed Carbonylative Homocoupling of Organoboronic Acids

We have developed a novel protocol for carbonylative homocoupling of arylboronic acids using dithiocarbamate esters as the carbonyl alternative. A series of arylboronic acids underwent smooth reaction with dithiocarbamate ester (Me2NCS2Me) in the presence of Pd(PPh3)2Cl2 catalyst, Cu(OAc)2·H2O additive, and Na2CO3 in DCE solvent, producing the biaryl ketones efficiently. The mechanism has been studied with the help of several control experiments that reveal the probability of thioamide intermediacy. Chemoselective homocoupling allows the postsynthetic modification of the product.

Temperature-Controlled Chemoselective Couplings of Alkyl Halides with Disulfides

An unprecedented, transition metal-free S-alkylation of disulfides with alkyl halides is developed for the first time, providing an efficient and green synthesis of thioethers and even thioesters. Notably, this new method allows the full utilization of both sulfur atoms of disulfides under chemical reductant-free conditions and can be easily scaled up in gram scale, showing good practical value. Control experiments suggested that water, unprecedentedly, serves as the terminal reductant of the whole reaction. Moreover, controllable N-alkyl thiopyridones can be readily obtained at a much lower reaction temperature from the same starting materials, suggesting a kinetic control of N-alkylation vs a thermodynamic control of the S-alkylation process may be involved in the reaction. Interestingly, a halo anion-mediated alkyl group migration from N-alkyl thiopyridones to S-alkyl pyridyl thioethers was observed, suggesting that the reaction may undergo a new and novel reaction mechanism.

Synthesis of S-Alkyl Dithiocarbamates via Multicomponent Reaction of Cyclic Sulfonium Salts with CS2 and Amines

A convenient and practical method for the synthesis of various S-alkyl dithiocarbamates through three-component reaction of sulfonium salts, CS2 and amines has been developed. The reaction proceeds efficiently without any catalyst and additive under mild and open-air conditions, making it potential applications in pharmaceutical chemistry and sulfur chemistry.

Metal-Free One-Pot Domino Synthesis of Oxazolidinethione Derivatives of Quaternary Amino Acids from α-Amino Esters and Aldehydes Using CS2

We present a streamlined, metal-free, one-pot domino approach to efficiently synthesize oxazolidinethione derivatives containing substituted quaternary amino acids. This method employs α-amino esters, aldehydes, and CS2 under mild conditions, constructing three new bonds (C-N, C-C, and C-O) to produce oxazolidinethione compounds featuring a quaternary center and a beta-hydroxy derivative in high yields. This scalable protocol enables the creation of libraries of biologically significant, intricate amino acid derivatives using amino esters and aldehydes.

Direct C-H Sulfuration: Synthesis of Disulfides, Dithiocarbamates, Xanthates, Thiocarbamates and Thiocarbonates

In light of the important biological activities and widespread applications of organic disulfides, dithiocarbamates, xanthates, thiocarbamates and thiocarbonates, the continual persuit of efficient methods for their synthesis remains crucial. Traditionally, the preparation of such compounds heavily relied on intricate multi-step syntheses and the use of highly prefunctionalized starting materials. Over the past two decades, the direct sulfuration of C-H bonds has evolved into a straightforward, atom- and step-economical method for the preparation of organosulfur compounds. This review aims to provide an up-to-date discussion on direct C-H disulfuration, dithiocarbamation, xanthylation, thiocarbamation and thiocarbonation, with a special focus on describing scopes and mechanistic aspects. Moreover, the synthetic limitations and applications of some of these methodologies, along with the key unsolved challenges to be addressed in the future are also discussed. The majority of examples covered in this review are accomplished via metal-free, photochemical or electrochemical approaches, which are in alignment with the overraching objectives of green and sustainable chemistry. This comprehensive review aims to consolidate recent advancements, providing valuable insights into the dynamic landscape of efficient and sustainable synthetic strategies for these crucial classes of organosulfur compounds.

Thiuram Disulfide Mediated Cu-Catalyzed Amidation of Terminal Alkynes: An Efficient Synthesis of Alkynyl Amides

Terminal alkynes undergo a CO-free aminocarbonylation reaction mediated by thiuram disulfides. Thiuram disulfide acts as the source of the carbamoyl group in the amidation of terminal alkynes in the presence of copper-based reagent and catalyst. A series of alkynyl amides has been prepared with several structural variations following the current one-pot two-step protocol. The reaction proceeds through a mixed disulfide intermediate, which has been isolated and characterized by single-crystal XRD analysis.

S-Alkylation of dithiocarbamates via a hydrogen borrowing reaction strategy using alcohols as alkylating agents

Herein, we report an operationally simple, environmentally benign and scalable approach towards the synthesis of S-benzyl/alkyl dithiocarbamates via a hydrogen borrowing reaction between alcohols and dithiocarbamate anions catalyzed using a hydroxyapatite-supported copper nano-catalyst. This strategy has a broad substrate scope and offers high yields of products using inexpensive and readily available alcohols as starting materials. The catalyst was prepared by easy and straightforward methods and analyzed by several analytical techniques, e.g., FESEM, HR-TEM, BET, XRD, EDS, and XPS, demonstrating the anchoring of Cu nanoparticles on hydroxyapatite in the zero oxidation state.

Base-mediated synthesis of cyclic dithiocarbamates from 1-amino-3-chloropropan-2-ol derivatives and carbon disulfide

An efficient method for the preparation of six-membered cyclic dithiocarbamates is described, in which triethylamine effectively promotes the reaction of 1-amino-3-chloropropan-2-ol derivatives with carbon disulfide. On the basis of the experimental and theoretical studies, a reaction mechanism is proposed to explain the difference between the present reaction and our previously reported carbon dioxide fixation.

Metal-free trifunctionalization of phenylacetylenes: an efficient one-pot two-step synthesis of gem-bis(dithiocarbamates)

The synthesis of phenacyl-bis(dithiocarbamates) has been reported by metal-free trifunctionalization of phenylacetylene systems by following a one-pot two-step strategy. Phenyl acetylene undergoes molecular bromine-mediated oxidative bromination followed by nucleophilic substitution with the freshly prepared dithiocarbamate salt which is prepared by the prompt reaction of amine and CS₂ in the presence of triethylamine base. A series of gem-bis(dithiocarbamates) are prepared using various secondary amines and phenylacetylene systems containing different substituents.

Cross-linked dithiocarbamate-modified cellulose with enhanced thermal stability and dispersibility as a sorbent for arsenite removal

Numerous reports have described dithiocarbamate (DTC)-modified cellulose sorbents that can selectively separate metal ions from water. We have previously synthesized a novel sorbent modified with DTC containing N-heterocycles in the backbone for the selective removal of hazardous metal ions. The sorbent was found to partially dissolve and aggregate in solution, reducing its sorption capacity. In this study, to prepare the sorbent for use as a soli-phase extraction material for the removal of arsenite (As^III) ions, we attempted to decrease the solubility of the sorbent. The sorbent was cross-linked with epoxy or complexed with iron, and the quantities of the modifiers were varied between 3.0 and 10 mol%. As a result, the iron-complexed sorbents were still partially soluble, and cross-linkage with 6.0 mol% of epoxy made the sorbent almost insoluble and dispersed in solution. This sorbent also exhibited the highest As^III sorption performance among the sorbents synthesized in this study. Although DTC-modified polymers are reported to lose their sorption capability after storage at 40 °C, the sorbent was found to be thermally stable. The optimum contact time and pH for As^III removal were 20 min and 3.0, respectively. The maximum sorption capacity of the epoxy-cross-linked sorbent, calculated from the Langmuir isotherm equation, was 600 μmol g^-1 (45 mg g^-1) at 25 °C. Additionally, the sorbent was highly selective toward As^III compared with previously reported sorbents and capable of removing approximately 97% of As^III from environmental water. In conclusion, cross-linking enhances the stability of the sorbents in solutions, which facilitates the removal of As^III from environmental water.

Synthesis of functionalized S-benzyl dithiocarbamates from diazo-compounds via multi-component reactions with carbon disulfide and secondary amines

Triflic acid promoted multi-component synthesis of functionalized S-benzyl dithiocarbamates from diazo compounds, carbon disulfide and secondary amines is reported. The reactions proceeded at room temperature and gave the desired dithiocarbamates in good yields. Wide-substrate scope and easy operation are the important features of this methodology.

Domino assembly of dithiocarbamates via Cu-catalyzed denitrogenative thiolation of iodotriazole-based diazo precursors

An efficient domino approach to assemble benzoxazoles and anthranilamides bearing dithiocarbamate moieties has been developed. The proposed route represents a Cu-catalyzed three-component reaction between readily available 5-iodo-1,2,3-triazoles, amines, and CS₂. The cascade transformation is based on a denitrogenative coupling of in situ formed dithiocarbamic acids with diazo intermediates, generated via annulation-triggered triazole ring-opening. This method is applicable to nucleophilic secondary amines and features good functional group compatibility.

Multicomponent Synthesis of S-Benzyl Dithiocarbamates from para-Quinone Methides and Their Biological Evaluation for the Treatment of Alzheimer's Disease

Multicomponent synthesis of biologically relevant S-benzyl dithiocarbamates from para-quinone methides, amines, and carbon disulfide are described under catalyst and additive-free conditions. The reactions proceeded at room temperature in a short span of time with excellent yields. One of the synthesized compounds, 3e showed considerable acetylcholinesterase (AChE) inhibitory (51.70 + 5.63% at 20 μm) and antioxidant (63.52 ± 1.15 at 20 μm) activities.

One-pot two-step dithiocarbamylation of styrenes: metal-free stereoselective synthesis of styrenyl dithiocarbamates

Styrenes have been functionalized to produce styrenyl dithiocarbamates by a one-pot two-step procedure without using any metal catalysts. Styrene was transformed into a bromo-derivative, which undergoes a domino nucleophilic substitution followed by elimination in the presence of a dithiocarbamate anion and triethylamine to produce trans-styrenyl dithiocarbamates exclusively. The reaction shows a wide substrate scope and good yields of products.

A Compendium of the Most Promising Synthesized Organic Compounds against Several Fusarium oxysporum Species: Synthesis, Antifungal Activity, and Perspectives

Vascular wilt caused by F. oxysporum (FOX) is one of the main limitations of producing several agricultural products worldwide, causing economic losses between 40% and 100%. Various methods have been developed to control this phytopathogen, such as the cultural, biological, and chemical controls, the latter being the most widely used in the agricultural sector. The treatment of this fungus through systemic fungicides, although practical, brings problems because the agrochemical agents used have shown mutagenic effects on the fungus, increasing the pathogen's resistance. The design and the synthesis of novel synthetic antifungal agents used against FOX have been broadly studied in recent years. This review article presents a compendium of the synthetic methodologies during the last ten years as promissory, which can be used to afford novel and potential agrochemical agents. The revision is addressed from the structural core of the most active synthetic compounds against FOX. The synthetic methodologies implemented strategies based on cyclo condensation reactions, radical cyclization, electrocyclic closures, and carbon-carbon couplings by metal-organic catalysis. This revision contributes significantly to the organic chemistry, supplying novel alternatives for the use of more effective agrochemical agents against F. oxysporum.

Revisiting applications of molecular iodine in organic synthesis

Molecular iodine contributes significantly to organic transformations in synthetic organic chemistry. It works effectively due to its mild Lewis acidic character, ability as an oxidizing agent, good moisture stability, and easy availability.