Electrochemical Enabled Cascade Phosphorylation of N-H/O-H/S-H Bonds with P-H Compounds: An Efficient Access to P(O)-X Bonds

Efficient and Sustainable Electrosynthesis of N-Sulfonyl Iminophosphoranes by the Dehydrogenative P-N Coupling Reaction

Iminophosphoranes are commonly used reagents in organic synthesis and are, therefore, of great interest. An efficient and sustainable iodide-mediated electrochemical synthesis of N-sulfonyl iminophosphoranes from readily available phosphines and sulfonamides is reported. This method features low amounts of supporting electrolytes, inexpensive electrode materials, a simple galvanostatic setup, and high conversion rates. The broad applicability could be demonstrated by synthesizing 20 examples in yields up to 90%, having diverse functional groups including chiral moieties and biologically relevant species. Furthermore, electrolysis was performed on a 20 g scale and could be run in repetitive mode by recycling the electrolyte, which illustrates the suitability for large-scale production. A reaction mechanism involving electrochemical mediation by the iodide-based supporting electrolyte is proposed, completely agreeing with all of the results.

Synthesis of Benzo[a]carbazoles and Dibenzo[c,g]carbazoles via Sequential Gold Catalysis and Photomediated Cyclization

Herein, we report a reaction protocol for the construction of benzo[a]carbazole and dibenzo[c,g]carbazole frameworks. The detailed gold catalytic reaction conditions developed for the challenging intermolecular carbon nucleophilic addition to internal alkynes are realized, giving the desired alkyne hydroarylation products in good yields. The resulting trisubstituted alkenes are able to undergo photomediated cyclization, furnishing the desired carbazole molecules with excellent yields and high efficiency.

CuH-Catalyzed Reductive Coupling of Nitroarenes with Phosphine Oxides for the Direct Synthesis of Phosphamides

A CuH-catalyzed reductive coupling of nitroarenes with phosphine oxides is developed, which produces a series of phosphamides in moderate to excellent yields with good functional group tolerance. Gram-scale synthesis and late-stage modification of nitro-aromatic functional molecule niclosamide are also successfully conducted. The mechanism study shows that the nitro group is transformed after being reduced to nitroso and a nucleophilic addition procedure is involved during the reaction.

Access to Azepino-Annulated Benzo[c]carbazoles Enabled by Gold-Catalyzed Hydroarylation of Alkynylindoles and Subsequent Oxidative Cyclization

Herein, we report a facile and efficient synthetic method to construct azepino[1,2-a]indoles through a novel gold(I)-catalyzed intramolecular hydroarylation of alkynylindoles. A wide range of functional groups can be well tolerated in this transformation, and the corresponding highly functionalized azepino[1,2-a]indole skeletons were obtained in moderate to excellent yields. Subsequent oxidation of the products gave the interesting and valuable polycyclic carbazoles, which were widely used as the key building blocks in materials science.

Selective Aerobic Oxidation of Csp3-H Bonds Catalyzed by Yeast-Derived Nitrogen, Phosphorus, and Oxygen Codoped Carbon Materials

Nitrogen, phosphorus, and oxygen codoped carbon catalysts were successfully synthesized using dried yeast powder as a pyrolysis precursor. The yeast-derived heteroatom-doped carbon (yeast@C) catalysts exhibited outstanding performance in the oxidation of C_sp³-H bonds to ketones and esters, giving excellent product yields (of up to 98% yield) without organic solvents at low O₂ pressure (0.1 MPa). The catalytic oxidation protocol exhibited a broad range of substrates (38 examples) with good functional group tolerance, excellent regioselectivity, and synthetic utility. The yeast-derived heteroatom-doped carbon catalysts showed good reusability and stability after recycling six times without any significant loss of activity. Experimental results and DFT calculations proved the important role of N-oxide (N⁺-O^-) on the surface of yeast@C and a reasonable carbon radical mechanism.

Electrochemical Oxidative N-H/P-H Cross-Coupling with H2 Evolution towards the Synthesis of Tertiary Phosphines

Tertiary phosphines(iii) find widespread use in many aspects of synthetic organic chemistry. Herein, we developed a facile and novel electrochemical oxidative N–H/P–H cross-coupling method, leading to a series of expected tertiary phosphines(iii) under mild conditions with excellent yields. It is worth noting that this electrochemical protocol features very good reaction selectivity, where only a 1 : 1 ratio of amine and phosphine was required in the reaction. Moreover, this electrochemical protocol proved to be practical and scalable. Mechanistic insights suggested that the P radical was involved in this reaction.

A facile and novel electrochemical oxidative N–H/P–H cross-coupling method for obtaining tertiary phosphines(iii) was developed.

Efficient and eco-friendly oxidative cleavage C–C bonds of 1,2-diols to ketones: electrochemistry vs thermochemistry

Two efficient methods for the oxidative cleavage C–C single bonds of vicinal tertiary diols by electrochemical and thermochemical strategies have been independently developed. The corresponding ketone products are smoothly assembled...