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Fluorinated cyclopropanes are highly desired pharmacophores in drug discovery owing to the rigid nature of the cyclopropane ring and the beneficial effects of C−F bonds on the pharmacokinetic properties, cell permeability, and metabolic stability of drug molecules. Herein a biocatalytic strategy for the stereoselective synthesis of mono‐fluorinated and gem‐difluoro cyclopropanes is reported though the use of engineered myoglobin‐based catalysts. In particular, this system allows for a broad range of gem‐difluoro alkenes to be cyclopropanated in the presence of diazoacetonitrile with excellent diastereo and enantiocontrol (up to 99 : 1 d.r. and 99 % e.e.), thereby enabling a transformation not currently accessible with chemocatalytic methods. The synthetic utility of the present approach is further exemplified through the gram‐scale synthesis of a key gem‐difluorinated cyclopropane intermediate useful for the preparation of fluorinated bioactive molecules. [ABSTRACT FROM AUTHOR]

The direct utilization of simple and abundant feedstocks in carbon‐carbon bond‐forming reactions to embellish sp3‐enriched chemical space is highly desirable. Herein, we report a novel photochemical deoxygenative hydroalkylation of unactivated alkenes with readily available carboxylic acid derivatives. The reaction displays broad functional group tolerance, accommodating carboxylic acid‐, alcohol‐, ester‐, ketone‐, amide‐, silane‐, and boronic ester groups, as well as nitrile‐containing substrates. The reaction is operationally simple, mild, and water‐tolerant, and can be carried out on multigram‐scale, which highlights the utility of the method to prepare value‐added compounds in a practical and scalable manner. The synthetic application of the developed method is further exemplified through the synthesis of suberanilic acid, a precursor of vorinostat, a drug used for the treatment of cutaneous T‐cell lymphoma. A novel mechanistic approach was identified using thiol as a nucleophilic catalyst, which forms a key intermediate for this transformation. Furthermore, electrochemical studies, quantum yield, and mechanistic experiments were conducted to support a proposed catalytic cycle for the transformation. [ABSTRACT FROM AUTHOR]

The advancement of sustainable photoredox catalysis in synthetic organic chemistry has evolved immensely because of the development of versatile and cost‐effective reagents. In recent years, a substantial effort has been dedicated to exploring the utility of formic acid salts in various photochemical reactions. In this context, formates have demonstrated diverse capabilities, functioning as reductants, sources of carbonyl groups, and reagents for hydrogen atom transfer. Notably, the CO2⋅– radical anion derived from formate exhibits strong reductant properties for cleaving both C−X and C−O bonds. Moreover, these salts play a pivotal role in carboxylation reactions, further highlighting their significance in a variety of photochemical transformations. The ability of formates to serve as reductants, carbonyl sources, and hydrogen atom transfer reagents reveal exciting possibilities in synthetic organic chemistry. This minireview highlights an array of captivating discoveries, underscoring the crucial role of formates in diverse and distinctive photochemical methods, enabling access to a wide range of value‐added compounds. [ABSTRACT FROM AUTHOR]

The palladium-catalyzed cross-coupling of the lithium anion of aryl tert -butyldimethylsilyl-protected cyanohydrins with aryl bromides followed by in situ deprotection with fluoride ion provides a convenient and versatile approach to biaryl ketones. This protocol represents the first example of a palladium-catalyzed arylation of a cyanohydrin, which functions as an acyl anion equivalent. Hence, in contrast to classical cross-coupling reactions, the pronucleophile component is incorporated in the product to permit further functionalization. We then highlight the synthetic utility of the new method with applications to bioactive biaryl ketones and the construction of a triaryl diketone that has been used to prepare an extended tetrathiafulvalene. [ABSTRACT FROM AUTHOR]