Metal-Free Dehomologative Oxidation of Arylacetic Acids for the Synthesis of Aryl Carboxylic Acids

A condition-tuned unorthodox approach to indole-3-carboxylic acids and anthranilic acids via carbon atom translocation

We describe a robust one-pot cascade method for the synthesis of indole-3-carboxylic acids using isatins and DMSO via a one-carbon translocation involving in situ generation of α,β-unsaturated methylvinylsulfoxide followed by amide bond cleavage and ring closure. The methodology has been extended to afford anthranilic acid derivatives by tuning the reaction conditions in the presence of molecular oxygen. Importantly, easy access to commercially available drugs, including tropisetron, is demonstrated.

Recent Advances of Green Catalytic System I2/DMSO in C–C and C–Heteroatom Bonds Formation

Developing a green, practical and efficient method for the formation of C–C and C–Heteroatom bonds is an important topic in modern organic synthetic chemistry. In recent years, the I2/DMSO catalytic system has attracted wide attention because of its green, high efficiency, atomic economy, low cost, mild reaction conditions and it is environment-friendly, which is more in line with the requirements of sustainable chemistry. Heteroatom-containing compounds have shown lots of important applications in pharmaceutical synthesis, agrochemicals, material chemistry and organic dyes. At present, the I2/DMSO catalytic system has been successfully applied to the synthesis of various heteroatom-containing compounds. The C–C and C–Heteroatom bonds have been formed efficiently, which has been proved to be a green and mild catalytic system. In this review, the research achievements of the I2/DMSO catalytic system in the formation of C–C and C–Heteroatom bonds from 2015 to date are described, and the research area is prospected. This review attempts to reveal the general law of iodine catalysis and lay a foundation for the design of new reactions.

Pd-catalyzed Ligand-Free ortho-Deuteration of Aromatic Carboxylic Acids with D2O

A ligand-free, palladium-catalyzed ortho-deuteration of aromatic carboxylic acid was developed using D2O as deuterium-source. Compared to their meta-substituted analogues, an unusually lower reactivity in para- and ortho-substituted benzoic acids toward hydrogen isotope exchange was observed. Further investigation revealed that the reaction temperature is a critical parameter for the reactivity, and the modified condition can afford deuterated products with good to excellent deuterium-incorporation.

MOF-Zn-NHC as an efficient N-heterocyclic carbene catalyst for aerobic oxidation of aldehydes to their corresponding carboxylic acids via a cooperative geminal anomeric based oxidation

As an efficient heterogenous N-heterocyclic carbene (NHC) catalyst, MOF-Zn-NHC was used in the aerobic oxidation of aryl aldehydes to their corresponding carbocyclic acids via an anomeric based oxidation. Features such as mild reaction conditions and no need for a co-catalyst or oxidative reagent can be considered as the major advantages of the presented method in this study.

As an efficient heterogenous N-heterocyclic carbene (NHC) catalyst, MOF-Zn-NHC was used in the aerobic oxidation of aryl aldehydes to their corresponding carbocyclic acids via an anomeric based oxidation.

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.

Iodine-catalyzed synthesis of N,N′-diaryl-o-phenylenediamines from cyclohexanones and anilines using DMSO and O2 as oxidants

An I₂/DMSO system has been successfully applied to synthesize N,N′-diaryl-o-phenylenediamines from cyclohexanones for the first time.

Iodine/DMSO oxidations: a contemporary paradigm in C–N bond chemistry

A new era in the organic synthetic world is demanding greener protocols for the execution of reactions.

tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides

This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.