An efficiently cobalt-catalyzed carbonylative approach to phenylacetic acid derivatives

Carbonylation of Polyfluorinated 1-Arylalkan-1-ols and Diols in Superacids

We describe the carbonylation of a series of mono and dihydroxy derivatives of polyfluorinated alkylbenzenes and benzocycloalkenes with OH groups at benzylic positions using carbon monoxide in the presence of a superacid (TfOH, a TfOH-SbF₅ mixture, or a FSO₃H-SbF₅ mixture). It was shown that the superacid-catalyzed addition of CO to various primary and secondary polyfluorinated alcohols and diols gives the corresponding mono- and dicarboxylic acids or lactones. The efficiency of various superacids depending on alcohol structure was evaluated, and FSO₃H-SbF₅ yielded the best results in most transformations. The addition of CO to secondary 1-arylalkan-1-ols containing vicinal fluorine atoms was found to be accompanied by elimination of HF with the formation of α,β-unsaturated aryl-carboxylic acids. In contrast to primary and secondary alcohols, conversion of tertiary perfluoro-1,1-diarylalkan-1-ols into carbonylation products is not complete, and the resulting carboxylic acids are easily decarboxylated after water treatment of the reaction mixture.

Visible-Light-Driven Reductive Carboxylation of Benzyl Bromides with Carbon Dioxide Using Formate as Terminal Reductant

Cheap and available formate can be seen formally as a carbon dioxide radical anion (CO₂^•-) combined with a hydrogen atom, where the CO₂^•- is not only a highly active radical but also a very powerful reductant. In this paper, we successfully realized a visible-light-driven carboxylation of benzyl bromides with carbon dioxide to prepare high-value arylacetic acids using potassium formate as a terminal reductant. This reaction is characterized by mild reaction conditions and a wide range of substrates. Moreover, under nitrogen atmosphere, the reaction can also achieve the carboxylation of benzyl bromides utilizing an excess of potassium formate. Mechanistic experiments indicate this carboxylation proceeded through CO₂^•-, which was generated from the oxidation of 1,4-diazabicyclo[2.2.2]octane with excited photosensitizer Ir(ppy)₂(dtbbpy)PF₆ in the presence of the potassium formate.

Single-Component Polycondensation of Bis(alkoxycarbonyldiazomethyl)aromatic Compounds To Afford Poly(arylene vinylene)s with an Alkoxycarbonyl Group on Each Vinylene Carbon Atom

The original synthetic strategy for a new type of poly(arylene vinylene) (PAV) is presented, where the C=C-bond-forming coupling of bis(alkoxycarbonyldiazomethyl)aromatic compounds is utilized as propagation. The strategy is unique in that the resulting PAVs have an alkoxycarbonyl group as an electron-withdrawing substituent on each vinylene carbon atom in the polymer main chain. Among the transition-metal catalysts examined in this study, RuCl(cod)Cp* (cod = 1,5-cyclooctadiene, Cp* = pentamethylcyclopentadienyl) is the most efficient, affording PAVs from a series of bis(alkoxycarbonyldiazomethyl)aromatic compounds with a high trans-C=C-forming selectivity of up to 90%. A PAV sample with a fluorenylene framework as an arylene moiety prepared by the Ru catalyst exhibited a hole mobility of 4 × 10^-6 cm² V^-1 s^-1.

An improved method for the synthesis of phenylacetic acid derivatives via carbonylation

2,4-Dichlorophenylacetic acid is synthesized in high yield via the carbonylation of 2,4-dichlorobenzyl chloride, and various experimental conditions are evaluated. Xylene, bistriphenylphosphine palladium dichloride, tetraethylammonium chloride and sodium hydroxide in solution are added to the reaction system and held at 80 °C under a CO atmosphere. 2,4-Dichlorophenylacetic acid is obtained in a maximum yield of 95%, and a mechanism for 2,4-dichlorobenzyl chloride carbonylation is proposed. The reaction system provides a mild, effective and novel means by which to prepare phenylacetic acid derivatives from their corresponding benzyl chloride derivatives.

Novel triple responsive polybenzimidazole synthesized via amine-ene Michael addition

BITO polyesters were synthesized for the first time, which show pH, CD and ROS responsiveness and have great potential as drug delivery systems.

Non-noble metal-catalysed carbonylative transformations

The main achievements on non-noble metal (Mn, Fe, Cu, Co, Ni) catalysed carbonylative transformations have been summarized and discussed.

A novel approach to study the structure-property relationships and applications in living systems of modular Cu(2+) fluorescent probes

A series of Cu²⁺ probe which contains 9 probes have been synthesized and established. All the probes were synthesized using Rhodamine B as the fluorophore, conjugated to various differently substituted cinnamyl aldehyde with C=N Schiff base structural motif as their core moiety. The structure-property relationships of these probes have been investigated. The change of optical properties, caused by different electronic effect and steric effect of the recognition group, has been analyzed systematically. DFT calculation simulation of the Ring-Close and Ring-Open form of all the probes have been employed to illuminate, summarize and confirm these correlations between optical properties and molecular structures. In addition, biological experiment demonstrated that all the probes have a high potential for both sensitive and selective detection, mapping of adsorbed Cu²⁺ both in vivo and environmental microbial systems. This approach provides a significant strategy for studying structure-property relationships and guiding the synthesis of probes with various optical properties.

Reactivity indices for natural bond orbitals: a new methodology

A new reactivity index has been defined; this parameter is focused on a molecule's natural bond orbitals (NBOs) and derives in a natural way from Fukui functions. NBOs have the advantage of being very localized, allowing the reaction site of an electrophile or nucleophile to be determined within a very precise molecular region. Finally, the indices for a representative set of organic molecules were calculated and their usefulness tested on some protonation reactions.