Synthesis of Diverse o-Arylthio-Substituted Diaryl Ethers by Direct Oxythiolation of Arynes with Diaryl Sulfoxides Involving Migratory O-Arylation

Facile synthesis of dibenzothiophene S-oxides from sulfinate esters

An efficient method to prepare dibenzothiophene S-oxides is disclosed. Suzuki-Miyaura cross-coupling of 2-bromoaryl sulfinate esters with arylboronic acids selectively at the bromo group followed by electrophilic cyclization of the resulting sulfinate ester moiety provides diverse dibenzothiophene S-oxides. Further transformations including Pummerer-type C-H propargylation and aryne reactions realize to synthesize highly functionalized dibenzothiophene derivatives.

Two Cascade Processes Initiated by the Insertion of Benzyne into the Se═O Bond

Two sets of cascade processes have been realized, both of which were initiated with a benzyne insertion into the Se═O bond. The key factors to differentiate these processes are based on the structures of diaryl selenium oxides and reaction conditions. When diaryl selenium oxides containing an ortho weak σ-electron-withdrawing group were used, triarylselenonium salts were obtained at room temperature, while ortho-(aryloxy)phenyl phenyl selanes could be produced from diaryl selenium oxides at 100 °C.

Synthesis of benzo[b]furans from alkynyl sulfoxides and phenols by the interrupted Pummerer reaction

The interrupted Pummerer reaction of alkynyl sulfoxides with phenols is disclosed. A wide range of benzo[b]furans were efficiently synthesized through unexplored electrophilic activation of the electron-deficient alkynyl sulfinyl group. Based on the good availability of alkynyl sulfoxides, we successfully prepared various functionalized benzo[b]furans from readily available alkynes, thiosulfonates, and phenols.

Diverse Synthesis of Triarylselenonium Salts and o-(Alkoxy)aryl Aryl Selanes via Insertion of Benzyne into the Se═O Bond

An insertion of benzyne into the Se═O bond has been realized. In this reaction, two types of compounds containing selenium could be synthesized from different substrates. When diaryl selenium oxides were used, triarylselenonium salts were furnished, while o-(alkoxy)phenyl phenyl selanes could be produced from aryl alkyl selenium oxides.

Construction of Diverse C–S/C-Se Bonds via Nickel Catalyzed Reductive Coupling Employing Thiosulfonates and A Selennofonate Under Mild Conditions

A nickel-catalyzed reductive cross coupling between organic iodides and thiosulfonates and a selennofonate under mild conditions is disclosed. This pracitical method provides facile access to a series of unsymmetrical thioethers...

MnSO4-Promoted S-O Bond Cleavage to Synthesize Functionalized Sulfonium Ylides from Activated Alkynes and Sulfoxides

A variety of functionalized sulfonium ylides were prepared in good yields through MnSO4-promoted S-O bond cleavage from activated alkynes and sulfoxides. Experimental results showed that MnSO4-catalyst played important roles to...

Reactions of Sulfoxides with Benzynes

Sulfoxides are important organic synthons that have been used in a variety of transformations. In this account, we focus on advances in the reaction of sulfoxides with benzynes, which can be divided into two types: benzyne ortho-difunctionalization and benzyne multifunctionalization.

1 Introduction

2 Benzyne ortho-Difunctionalization

3 Benzyne Multifunctionalization

4 Conclusion

Access to diverse organosulfur compounds via arynes: a comprehensive review on Kobayashi's aryne precursor

Arynes are highly reactive transient intermediates having enormous applications in organic synthesis. In the last three decades aryne chemistry has shown incredible developments in carbon-carbon and carbon-heteroatom bond formation reactions. After the discovery of Kobayashi's protocol for the generation of aryne intermediates in a mild way, this field of chemistry witnessed rapid growth in synthetic organic chemistry. One aspect of development in this field involves C-S bond formation under mild conditions which has a tremendous scope for the synthesis of various important organosulfur building blocks.

Sulfurane [S(IV)]-Mediated Fusion of Benzynes Leads to Helical Dibenzofurans

Here we disclose a sulfurane-mediated method for the formation of dimeric dibenzofuran helicenes via the reaction between diaryl sulfoxides and hexadehydro-Diels-Alder (HDDA) derived benzynes. A variety of S-shaped and U-shaped helicenes were formed under thermal conditions. Both experimental and DFT studies support a sulfur(IV)-based coupling (aka ligand coupling) mechanism involving tetracarbo-ligated S(IV) intermediates undergoing reductive elimination to afford the helicene products. This process involves the de novo generation of five new rings in a single operation and constitutes a new method for the construction of topologically interesting, polycyclic aromatic compounds.

Palladium-Catalyzed Sulfinylation of Aryl- and Alkenylborons with Sulfinate Esters

An efficient, direct sulfinylation of organoborons catalyzed by palladium is disclosed. Treatment of organoborons and sulfinate esters in the presence of a palladium precatalyst provided a broad range of sulfoxides. Various organosulfur compounds having oxidizable functional groups were successfully prepared through the sulfoxide synthesis.

o-Quinone Methides and o-Quinone Sulfides via Arynes: Synthesis of Ortho-Disubstituted Arenes and Heterocycles

In recent decades, o-quinone methides and o-quinone sulfides have been extensively highlighted as reactive intermediates for the synthesis of diversely functionalized ortho-disubstituted arenes and heterocycles. Additionally, ortho-disubstituted arenes offer a constructive path for the synthesis of fused carbocycles, heterocycles, natural products, and drug candidates. In the lieu of that, this Synopsis highlights a comprehensive overview on the potential applications of in situ generated o-quinone methides and o-quinone sulfides for one-pot synthesis of ortho-disubstituted arenes and heterocycles via arynes.

Construction of 6H-benzo[c]thiochromenes via a tandem reaction of arynes with thionoesters

A mild and transition-metal free method has been proposed for the synthesis of 6H-benzo[c]thiochromenes via the tandem reactions of arynes with thionoesters.

Synthesis of Decaarylanthracene with Nine Different Substituents

A synthesis of decaarylanthracene with nine different substituents has been accomplished by a coupling/ring-transformation strategy. The oxidation of tetraarylthiophenes with four different substituents to the corresponding thiophene S-oxides and a [4 + 2] cycloaddition with a double benzyne precursor afforded a multiply arylated naphthalene derivative. Subsequently, the naphthalene derivative was converted into a naphthalyne, and then a [4 + 2] cycloaddition of another thiophene S-oxide provided decaarylanthracenes with nine different aryl groups.

Synthesis of α-Aminophosphonates via Phosphonylation of an Aryne-Imine Adduct

Multicomponent phosphonylation is accomplished upon the reaction of an imine with an aryne generated in situ in the presence of a dialkyl phosphite. This transition-metal-free protocol shows a broad substrate scope, providing a variety of α-aminophosphonates in moderate to good yields. A plausible mechanism for the reaction is proposed based on a deuterium exchange experiment.

One-step synthesis of benzo[b]thiophenes by aryne reaction with alkynyl sulfides

An aryne reaction with alkynyl sulfides affording benzo[b]thiophenes is disclosed. A wide range of 3-substituted benzothiophenes were synthesized from easily available o-silylaryl triflates and alkynyl sulfides in a one-step intermolecular manner. The synthesis of diverse multisubstituted benzothiophene derivatives involving a pentacyclic compound was achieved by virtue of the good functional group tolerance and versatile C2 functionalizations.

Sulfoxide synthesis from sulfinate esters under Pummerer-like conditions

A facile synthetic method for the preparation of allyl sulfoxides by S-allylation of sulfinate esters proceeds through sulfonium intermediates without [3,3]-sigmatropic rearrangement and further Pummerer-type reactions of the resulting allyl sulfoxides. On the basis of the plausible reaction mechanism involving sulfonium salt intermediates, S-alkynylation and S-arylation were also accomplished.

Bond-Forming and -Breaking Reactions at Sulfur(IV): Sulfoxides, Sulfonium Salts, Sulfur Ylides, and Sulfinate Salts

Organosulfur compounds have long played a vital role in organic chemistry and in the development of novel chemical structures and architectures. Prominent among these organosulfur compounds are those involving a sulfur(IV) center, which have been the subject of countless investigations over more than a hundred years. In addition to a long list of textbook sulfur-based reactions, there has been a sustained interest in the chemistry of organosulfur(IV) compounds in recent years. Of particular interest within organosulfur chemistry is the ease with which the synthetic chemist can effect a wide range of transformations through either bond formation or bond cleavage at sulfur. This review aims to cover the developments of the past decade in the chemistry of organic sulfur(IV) molecules and provide insight into both the wide range of reactions which critically rely on this versatile element and the diverse scaffolds that can thereby be synthesized.

Sequential cycloaddition and ring expansion reaction of arynes and methylenebenzothiopheneones: synthesis of a benzo-fused eight-membered ring via sulfonium ylides

Efficient construction of benzo-fused eight-membered ring containing sulfur. New reaction profile with sulfonium ylides.

Application of Sulfur Ylides in 1,2-Difunctionalization of Arynes via Insertion into a C-S σ-Bond

A novel reactivity of sulfur ylides has been demonstrated in a transition-metal-free protocol to access ortho-substituted thioanisole derivatives by insertion of arynes into a C-S σ-bond in moderate to good yields. The reaction involves the formation of C-C and C-S bonds and consecutive breaking of two C-S bonds under operationally mild reaction conditions.

A domino reaction of 2-isocyanophenyloxyacrylate and aryne to synthesize arenes with vicinal olefin and benzoxazole

An unusual domino reaction of 2-isocyanophenyloxyacrylate and aryne has been disclosed. The present strategy experiences nucleophilic addition, Michael addition, carbon–oxygen cleavage, and cyclization, thus enabling the quick aryne vicinal difunctionalization by the installation of a benzoxazole and an olefin.

Recent advances in molecular rearrangements involving aryne intermediates

A concise account on the recent developments in molecular rearrangements proceeding via the aryne intermediate is presented thereby shedding light on the synthetic potential of this versatile intermediate.

Expanding the synthesizable multisubstituted benzo[b]thiophenes via 6,7-thienobenzynes generated from o-silylaryl triflate-type precursors

Various 2,3-disubstituted 6,7-thienobenzynes have been efficiently generated from the corresponding o-silylaryl triflate-type precursors by activation with fluoride ions. The method has expanded the scope of synthesizable multisubstituted benzothiophenes, including those with various heteroatom substituents, and can be applied to the synthesis of EP4 antagonist analogs.

Various multisubstituted benzothiophenes, including those with various heteroatom substituents and EP4 antagonist analogs, have been prepared easily via 6,7-thienobenzynes generated from o-silylaryl triflate-type precursors.