Tao Miao

Direct use of formamides as amino group sources via C–N bond cleavage: a catalytic oxidative synthesis of α-ketoamides from acetophenones and formamides under metal-free conditions

An efficient and direct use of formamides as amino group sources for the synthesis of α-ketoamides was developed under metal-free conditions. The reaction was based on the oxidative coupling of acetophenones with formamides and generated the desired products in good yields in the presence of t-BuOOH/I(2)/PhCO(2)H.

Visible-Light Photoredox Catalysis: Direct Synthesis of Sulfonated Oxindoles from N-Arylacrylamides and Arylsulfinic Acids by Means of a Cascade C-S/C-C Formation Process.

A novel photocatalytic synthesis of sulfonated oxindoles from N-arylacrylamides and arylsulfinic acids was developed by means of a cascade C-S/C-C bond-formation process. This method provides mild, efficient, and atom-economical access to various sulfonated oxindoles in water.

A Sulfenylation Reaction: Direct Synthesis of 3-Arylsulfinylindoles from Arylsulfinic Acids and Indoles in Water

A novel and efficient electrophilic sulfenylation of indoles with arylsulfinic acids is realized. The reaction utilizes readily available starting materials in water under catalyst- and additive-free conditions, providing an alternative and attractive approach to 3-arylsulfinylindoles with high yields. Preliminary mechanistic investigation suggested that the reaction is through an electrophilic substitution process.

Microwave-accelerated Pd-catalyzed desulfitative direct C2-arylation of free (NH)-indoles with arylsulfinic acids.

The rapid and efficient direct C2-arylation of free (NH)-indoles with arylsulfinic acids proceeded through a microwave-accelerated palladium-catalyzed desulfitation reaction. By using PdCl2 as a catalyst, silver acetate as an oxidant, and H2SO4 as an additive, arylsulfinic acids with both electron-donating and electron-withdrawing groups underwent desulfitative coupling with an array of free (NH)-indoles, thereby selectively providing C2-arylindoles in good yields.

Visible-light-induced dual C–C bond formation via selective C(sp3)–H bond cleavage: efficient access to alkylated oxindoles from activated alkenes and simple ethers under metal-free conditions

A visible-light-induced oxidative difunctionalization of activated alkenes with simple ethers via selective C(sp3)–H bond cleavage and dual C–C bond formation was developed. The reaction provides mild, efficient and atom economical access to alkylated oxindoles at room temperature under metal-free conditions.

Regioselective synthesis of triazoles via base-promoted oxidative cycloaddition of chalcones with azides in aqueous solution

A base-promoted oxidative cycloaddition of chalcones with azides in aqueous solution has been developed under transition-metal-free conditions, which provides a green method for the regioselective synthesis of trisubstituted triazoles in good yields.

Photo-Driven Synthesis of C6-Polyfunctionalized Phenanthridines from Three-Component Reactions of Isocyanides, Alkynes, and Sulfinic Acids by Electron Donor–Acceptor Complex

A novel and efficient photoinduced synthesis of C6-polyfunctionalized phenanthridines from three-component reactions of isocyanides, alkynes and sulfinic acids was developed. The reactions generated the corresponding products with high selectivity through the photochemical activity of the formed electron donor-acceptor (EDA) complex during the reaction via a radical tandem process under mild conditions.

Palladium‐Catalyzed Direct C2 Arylation of N‐Substituted Indoles with 1‐Aryltriazenes

A novel and efficient palladium-catalyzed C2 arylation of N-substituted indoles with 1-aryltriazenes for the synthesis of 2-arylindoles was developed. In the presence of BF3⋅OEt2 and palladium(II) acetate (Pd(OAc)2), N-substituted indoles reacted with 1-aryltriazenes in N,N-dimethylacetamide (DMAC) to afford the corresponding aryl-indole-type products in good to excellent yields.

Selective Synthesis of Diaryl Sulfoxides and m-Arylthio Sulfones from Arylsulfinic Acids and Arenes via BF3-Promoted C–S Bond Formation

A novel and efficient method for selective synthesis of diaryl sulfoxides and m-arylthio sulfones has been achieved from readily available arylsulfinic acids and arenes via an unusual sulfinyl cation, providing a range of structurally diverse products in good to excellent yields under mild conditions. Notably, mechanistic investigations suggested m-arylthio sulfones were generated from diaryl sulfoxides and sulfinyl cation by a sequence of redox reaction and electrophilic aromatic substitution process.

Excess-electron-induced C–C bond formation in transformation of carbon dioxide

This study presents a new fixation method of CO2 through excess-electron-induced C–C bond formation using quantum chemical method. Because of active CO2−˙ with a distinct radical character at the carbon center, two divalent anion complexes [O2C–C6H6–CO2]2− (cis-II and trans-II) are obtained via C–C bond formation between the carbon atom of C6H6 and the carbon atom of CO2 in the process of CO2−˙ radical attacking on benzene molecule. Furthermore, the transformations of cis-II and trans-II are predicted. We found that the more favorable transformation is for cis-II. It can produce terephthalic and one H2 molecule via two H-atom elimination with the energy barrier of 35.70 kcal mol−1. Furthermore, we found that the formed hydrogen bond complex CO2–HCN did not reduce the energy barrier; however, it could reduce the energy of the transition state with respect to that of the reactant, due to it dispersing the charge of benzene ring.