Regioselective Thiol-yne Reaction of Thiol with ((Methyl-d3)sulfonyl)ethyne: Synthesis of (2-((Methyl-d3)sulfonyl)vinyl)sulfides.

Herein, we have developed a new method for the synthesis of ((methyl-d3)sulfonyl)ethyne, which is cost-effective and environmentally friendly and can be synthesized at the gram level. As an ideal thiol-yne reagent, it can be reacted with various types of thiols to afford (Z)- and (E)-type vinyl sulfides under different conditions with high selectivity. In addition, it can complete the conformational transition from Z- to E-type products under suitable conditions, and can also carry out further derivatization smoothly. The deuterium content of all products was greater than 99%. The preliminary mechanistic studies support the visible light-mediated radical course, and herein provide a novel and efficient synthetic strategy for the direct introduction of deuterated methyl groups, enriching the methods for the construction of C-S bond-containing compounds.

Overcoming Radical Stability Order via DABCO-Triggered Desulfurization: Visible-Light-Promoted 1,2,4-Trifunctionalization of Butenyl Benzothiazole Sulfone with Thiosulfonate.

A radical 1,2,4-trifunctional reaction of thiosulfonate to unactivated olefin is achieved by a migration strategy under mild conditions. In this reaction, the more unstable primary free radicals are in situ generated after the migration of heteroaryl groups in the presence of DABCO. This trifunctionalization of unactivated olefins involves two C-S bond formations and one C-C bond formation.

Regioselective 1,4-/1,3-Difunctionalization of 1,3-Enynes with Selenosulfonates in Water.

1,4-/1,3-Regioselective bifunctionalization of 1,3-enynes with selenosulfonates in water under catalyst-free conditions for the construction of sulfonyl allene and 1,3-disulfonyl-conjugated dienes respectively have been developed. The reactions feature mild reaction conditions in aqueous solution and remarkable regioselectivity controlled by substrates.

Copper-Catalyzed Synthesis of S-S Bond-Containing Silanols from SCBs and Trisulfide-1,1-dioxides.

In this work, an efficient method for the copper-catalyzed ring-opening hydrolysis of silacyclobutanes to silanols was developed. This strategy has the advantages of friendly reaction conditions, simple operation, and good functional group compatibility. No additional additives are required in the reaction, and the S-S bond can also be introduced into the organosilanol compounds in one step. Furthermore, the success at the gram scale demonstrates the great potential of the developed protocol for practical industrial applications.

Photoinduced Construction of Thieno[3,4-c]quinolin-4(5H)-ones/Selenopheno[3,4-c]quinolin-4(5H)-ones Using Diphenyl Disulfide or Diphenyl Diselenide as Sulfur or Selenium Sources.

A photocatalytic synthesis of thieno[3,4-c]quinolin-4(5H)-ones/selenopheno[3,4-c]quinolin-4(5H)-ones using diphenyl disulfide or diphenyl diselenide as sulfur or selenium sources was developed. Two C-S/Se bonds and one C-C bond were constructed simultaneously without transition metals and other additives.

Nickel-Catalyzed Acid Chlorides with Tetrasulfides for the Synthesis of Thioesters and Acyl Disulfides.

Herein, we report a novel method for the synthesis of thioesters and acyl disulfides via nickel-catalyzed reductive cross-electrophile coupling of acid chlorides with tetrasulfides. This approach for the synthesis of thioesters and acyl disulfides is convenient and practical under mild reaction conditions, relying on easy availability. In addition, a wide range of thioesters and acyl disulfides were obtained in medium to good yields with good functional group tolerance. Moreover, thioesters and acyl disulfides can also be prepared at the gram scale, indicating that they have certain potential for industrial application.

Clinical Efficacy and Imaging Observation of Three Surgical Approaches in Treatment of Thoracolumbar Fractures.

Objective: To observe the efficacy and imaging of surgical treatment of thoracolumbar fractures via the paravertebral muscle space approach. Methods: A retrospective analysis was conducted on patients with thoracolumbar fractures receiving surgery in Baoding First Central Hospital from January 2019 to December 2020. According to different surgical approaches, they were divided into paravertebral approach group, posterior median approach group and minimally invasive percutaneous approach group. They received surgery via the paravertebral muscle space approach, posterior median approach and minimally invasive percutaneous approach, respectively. Results: Statistically significant differences were found in surgical duration, intraoperative bleeding volume, intraoperative fluoroscopy frequency, postoperative drainage volume and hospital stay among the three groups. One year after surgery, the VAS, ADL and JOA scores of the paravertebral approach group and the minimally invasive percutaneous approach group had statistically significant differences from the posterior median approach group (P < 0.05). Conclusion: For the surgical treatment of thoracolumbar fractures, the clinical efficacy of the paravertebral muscle space approach is superior to that of the traditional posterior median approach, and the clinical efficacy of the minimally invasive percutaneous approach is similar to that of the posterior median approach. All the three approaches can effectively improve the postoperative function and pain symptoms of patients without increasing the incidence of complications. Compared with the posterior median approach, the surgery via the paravertebral muscle space and minimally invasive percutaneous approaches presents shorter surgical duration, less bleeding and shorter hospital stay, which is more conducive to postoperative recovery of patients.

Nickel-Catalyzed Reductive Thiolation of Unactivated Alkyl Bromides and Arenesulfonyl Cyanides.

The cross-electrophile coupling between unactivated alkyl bromides with arenesulfonyl cyanides catalyzed by Ni(acac)2 under reductive conditions to form unsymmetrical sulfides is developed. This approach for sulfide synthesis is practical, relies on available, unfunctionalized materials such as alkyl (pseudo)halides, and is scalable. This catalytic strategy provides a complementary method for the preparation of unsymmetrical alkyl-aryl sulfides under mild conditions with good functional group tolerance.

Transition-Metal-Free Decarboxylative Cyclization of N-Arylacrylamides with 2,2-Difluoro-2-(phenylthio)acetic Acid: Synthesis of Thiodifluorooxindole Derivatives.

An efficient transition-metal-free decarboxylative cyclization of N-arylacrylamides with 2,2-difluoro-2-(phenylthio)acetic acid for the construction of thiodifluoroindoleone derivatives is described. This strategy features stable and readily available substrates, mild reaction conditions, and transition-metal-free catalysts. Notably, this protocol has successfully applied to synthesis of gem-difluoroalkenes, which exist in numerous biologically active compounds.

Base-Promoted Multicomponent Reactions: A Synthesis of 2-Amino-1,3-selenazole Derivatives.

New practical synthesis of 2-amino-1,3-selenazole with transition metal-free multicomponent reaction is reported here. A series of 2-amino-1,3-selenazole derivatives were afforded by the nucleophilic addition of amines to isoselenocyanate formed in situ, followed by Michael addition reaction and aromatization. The products were isolated from moderate to excellent yields.

Copper-Catalyzed Chemoselective Cyclization Reaction of 2-Isocyanoacetophenone: Synthesis of 4-Hydroxyquinoline Compounds.

A copper-catalyzed intramolecular cyclization reaction of 2-isocyanoacetophenone derivatives to afford 4-hydroxyquinolines chemoselectively is described. The transformation proceeds through enol tautomerism and a subsequent C-C bond formation. Compared to previous methods, this study provides a new protocol for the construction of 4-hydroxyquinoline compounds from functionalized isocyanides under mild conditions.

Iron(iii) chloride-promoted cyclization of α,ß-alkynic tosylhydrazones with diselenides: synthesis of 4-(arylselanyl)-1H-pyrazoles.

A highly efficient iron(iii) chloride-promoted cyclization between α,ß-alkynic tosylhydrazones and diselenides to form a 4-(arylselanyl)-1H-pyrazole skeleton is studied. This reaction forms C-N and C-Se bonds in one step by utilizing inexpensive iron(iii) chloride instead of expensive transition metal additives. This strategy features easily synthesized substrates, mild reaction conditions and high tolerance to functional groups.

Nickel-Catalyzed Thiolation and Selenylation of Cycloketone Oxime Esters with Thiosulfonate or Seleniumsulfonate.

A nickel-catalyzed ring opening and, subsequently, reductive cross-coupling of cycloketone oxime esters with thiosulfonate or seleniumsulfonate are reported, which involves C-C bond cleavage and C(sp3)-S or C(sp3)-Se bond formation. Notably, S-aryl/alkyl sulfonothioates and Se-alkyl seleniumsulfonothioates could be employed in this reaction to afford a variety of 1° and 2° alkyl sulfides, aryl sulfides, and 1° and 2° alkyl selenides in one step. This strategy features easily available substrates and mild reaction conditions.

Visible Light-Induced Co- or Cu-Catalyzed Selenosulfonylation of Alkynes: Synthesis of ß-(Seleno)vinyl Sulfones.

A visible light-induced Co- or Cu-catalyzed selenosulfonylation of alkynes for the synthesis of ß-(seleno)vinyl sulfones is demonstrated. This method utilizes a low-cost cobalt salt or metal copper as the catalysts. The reaction goes through a photoinduced free radical addition of selenosulfonates to alkynes for the 1,2-selenosulfonylation of alkynes under mild conditions.

Nickel-Catalyzed Defluorinative Reductive Cross-Coupling Reaction of gem-Difluoroalkenes with Thiosulfonate or Selenium Sulfonate.

A nickel-catalyzed defluorinative reductive cross-coupling of gem-difluoroalkenes with thiosulfonate or selenosulfonates is described. The reaction involves the formation of thiolated or selenylated monofluoroolefins via regioselective C-F bond cleavage and C-S or C-Se bond formation and features easily available substrates, mild reaction conditions, and high E-selectivity. One of the derivatives by further cross coupling with PhMgBr exhibited an aggregation-induced emission enhancement effect.

Palladium Catalyzed Insertion Reaction of Isocyanides with 3-Arylisoxazol-5(4H)-ones: Synthesis of 4-Aminomethylidene Isoxazolone Derivates.

A palladium catalyzed insert reaction of isocyanides to 3-arylisoxazol-5(4H)-ones for the construction of 4-aminomethylidene isoxazolone derivates is reported. In this transformation, only the C-H bond of the methylene group was involved while the remaining ring structure was retained. In general, this work provided a new protocol for the synthesis of 4-aminomethylidene isoxazolones.

Thermo-Promoted Reactions of Anthranils with Carboxylic Acids, Amines, Phenols, and Malononitrile under Catalyst-Free Conditions.

A convenient and atom-economical procedure for the thermo-promoted reactions of anthranil with different substrates was developed. The catalyst-free process affords various useful building blocks with good to moderate yields. This chemistry enables several step- and cost-effective approaches for biologically interesting molecules and provides an efficient platform for the investigation of untapped reactions at high temperature.

Cascade Trisulfur Radical Anion (S3•-) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles.

Trisulfur radical anion (S3•-) mediated reactions with in situ formed azoalkenes and α,ß-usaturated N-sulfonylimines for the construction of 1,2,3-thiadiazoles and isothiazoles has been developed. S3•- is in situ generated from potassium sulfide in DMF. These two approaches provide a new, safe, and simple way to construct 4-subsituted 1,2,3-thiadiazoles, 5-subsituted 1,2,3-thiadiazoles, and isothiazole in good yields. The reactions include the formation of the new C-S and N-S bonds via S3•- addition and electron detosylation under mild conditions.

[4 + 1] Cycloaddition Reaction of α,ß-Alkynic Hydrazones and KSCN under Transition-Metal-Free Conditions: Synthesis of N-Iminoisothiazolium Ylides.

A novel heteroannulation reaction between α,ß-alkynic hydrazones and potassium thiocyanate has been developed for the synthesis of N-iminoisothiazolium ylides. The transformation features wide substrate scope, functional tolerance, and easy operation. This investigation involves a [4 + 1]-type cycloaddition reaction and C-S/S-N bond formation under transition-metal-free conditions. The application of this transformation to the gram-scale preparation of the N-imide ylide is also accomplished.

I2/TBHP-Mediated Oxidative Coupling of Amino-Based Bisnucleophiles and Isocyanides: Access to 2-Aminobenzoxazinones, 2-Aminobenzoxazines, and 2-Aminoquinazolines under Metal-Free Conditions.

An I2/ tert-butyl hydroperoxide (TBHP)-mediated oxidative coupling reaction of isocyanides with amino-based bisnucleophiles is described for the synthesis of 2-aminobenzoxazinones, 2-aminobenzoxazines, and 2-aminoquinozolines in moderate to excellent yields. Furthermore, this method provides a simple and practical method to construct potential functionalized biologically active molecules.