Transition metal-free decarboxylative olefination of carboxylic acid salts.

The cost-effective and efficient synthesis of alkenes is highly significant due to their extensive applications in both synthetic and polymer industries. A transition metal-free approach has been devised for the chemoselective olefination of carboxylic acid salts. This modular approach provides direct access to valuable electron-deficient styrenes in moderate to good yields.

Cobalt-Catalyzed Allylic Alkylation at sp-Carbon Centers.

The rising demand and financial costs of noble transition metal catalysts have emphasized the need for sustainable catalytic approaches. Over the past few years, base-metal catalysts have emerged as ideal candidates to replace their noble-metal counterparts because of their abundance and easiness of handling. Despite the significant advancements achieved with precious transition metals, earth-abundant cobalt catalysts have emerged as efficient alternatives for allylic substitution reactions.

Cobalt-catalyzed decarboxylative difluoroalkylation of nitrophenylacetic acid salts.

The selective installation of fluorine-containing groups into biologically relevant molecules has been used as a common strategy for the development of pharmaceutically active molecules. However, the selective incorporation of -difluoromethylene groups next to sterically demanding secondary and tertiary alkyl groups remains a challenge. Herein, we report the first cobalt-catalyzed regioselective difluoroalkylation of carboxylic acid salts.

Cobalt-Catalyzed Decarboxylative Allylations: Development and Mechanistic Studies.

In recent years, there has been a concerted drive to develop methods that are greener and more sustainable. Being an earth-abundant transition metal, cobalt offers an attractive substitute for commonly employed precious metal catalysts, though reactions engaging cobalt are still less developed. Herein, we report a method to achieve the decarboxylative allylation of nitrophenyl alkanes, nitroalkanes, and ketones employing cobalt.

Photoredox/Cobalt Dual-Catalyzed Decarboxylative Elimination of Carboxylic Acids: Development and Mechanistic Insight.

Recently, dual-catalytic strategies towards the decarboxylative elimination of carboxylic acids have gained attention. Our lab previously reported a photoredox/cobaloxime dual catalytic method that allows the synthesis of enamides and enecarbamates directly from N-acyl amino acids and avoids the use of any stoichiometric reagents. Further development, detailed herein, has improved upon this transformation's utility and further experimentation has provided new insights into the reaction mechanism.

Stabilization of NaBH in Methanol Using a Catalytic Amount of NaOMe. Reduction of Esters and Lactones at Room Temperature without Solvent-Induced Loss of Hydride.

Rapid reaction of NaBH with MeOH precludes its use as a solvent for large-scale ester reductions. We have now learned that a catalytic amount of NaOMe (5 mol %) stabilizes NaBH solutions in methanol at 25 °C and permits the use of these solutions for the reduction of esters to alcohols. The generality of this reduction method was demonstrated using 22 esters including esters of naturally occurring chiral γ-butyrolactone containing dicarboxylic acids.