Direct Synthesis of Biphenyl-2-carbonitriles by Rh(III)-Catalyzed C-H Hiyama Cross-Coupling in Water

Nitrogen-Based Organofluorine Functional Molecules: Synthesis and Applications

Fluorine and nitrogen form a successful partnership in organic synthesis, medicinal chemistry, and material sciences. Although fluorine-nitrogen chemistry has a long and rich history, this field has received increasing interest and made remarkable progress over the past two decades, driven by recent advancements in transition metal and organocatalysis and photochemistry. This review, emphasizing contributions from 2015 to 2023, aims to update the state of the art of the synthesis and applications of nitrogen-based organofluorine functional molecules in organic synthesis and medicinal chemistry. In dedicated sections, we first focus on fluorine-containing reagents organized according to the type of fluorine-containing groups attached to nitrogen, including N-F, N-RF, N-SRF, and N-ORF. This review also covers nitrogen-linked fluorine-containing building blocks, catalysts, pharmaceuticals, and agrochemicals, underlining these components' broad applicability and growing importance in modern chemistry.

Palladium-Catalyzed Ring-Opening Defluorinative Hiyama Cross-Coupling of gem-Difluorocyclopropanes with Arylsilanes

We report an efficient palladium-catalyzed ring-opening defluorinative Hiyama cross-coupling of gem-difluorocyclopropanes with structurally diverse (hetero)arylsilanes through C-C bond activation and C-F bond cleavage. This regioselective ring-opening defluorinative Hiyama cross-coupling features a broad substrate scope with excellent functional group compatibility, affording a diverse variety of linear 2-fluoroallylic scaffolds in good yields with high Z-selectivity.

Palladium-Catalyzed Hiyama Cross-Coupling of Heterocyclic Phosphonium Salts with Arylsilanes

We report herein the palladium-catalyzed Hiyama cross-coupling of heterocyclic phosphonium salts with diverse (hetero)arylsilanes through C-P bond cleavage, providing an alternative approach for the highly regioselective functionalization of pyridines and relevant nitrogen-containing heterocycles. This silicon-based protocol is amenable to gram-scale synthesis and also applicable to the late-stage functionalization of pharmaceutically relevant complex molecules.

2-Pyridone-Enhanced Mn-Catalysis for the Synthesis of ortho-Deuterated Aromatic Nitriles

We herein present a method for the synthesis of ortho-deuterated aryl nitrile using Mn(CO)5Br as catalyst with CH3OD as deuteratium source, where the structure of aryl imidates is used for interconversion with a cyanide group. This method features a broad substrate range and excellent functional group tolerance, allowing late modification of various complex molecules with good yields and deuterium incorporation. Mechanistic studies suggest that 2-pyridone is crucial to the success of this chemistry, serving as an endogenous base that enhances the rate of hydrogen isotope exchange.

Rhodium-Catalyzed C-H Arylation of Indoles with Arylsilanes at Room Temperature

The Cp*Rh-catalyzed C-H arylation of indoles with arylsilanes is developed. This C-H activation transformation allows for the Rh-catalyzed indole C2 arylation to overcome the limitations of requiring strong directing group assistance and high-temperature conditions, achieving a room-temperature transformation driven by a weak directing group. Cp*Rh/MeOH catalytic media are considered a key factor enabling this transformation to occur under mild conditions, and experimental studies and theoretical calculations were performed to rationalize the reaction mechanisms and the influence of methanol as a solvent in promoting the reaction.

Tunable Rh(III)-Catalyzed C(sp2)-H Bond Functionalization of Aryl Imidates with Cyclic 1,3-Diones: Strategic Use of Directing Groups

A tunable Rh(III)-catalyzed C(sp2)-H bond functionalization of aryl imidates with cyclic 1,3-diones was developed. With suitable and straightforward reaction condition adjustments, the C-H bond functionalization of diverse aryl imidates with cyclic 1,3-diones occurred smoothly and precisely at room temperature. Accompanied by different directing group transformations, a series of corresponding aryl nitriles, hydrophenanthridin-1(2H)-ones, spiro isoindoles, or hydrophenanthridine-1,6(2H,5H)-diones were synthesized in good yields to provide a rational directing group utilization strategy for the Rh(III)-catalyzed C(sp2)-H bond activation. Control experiments and primary mechanistic studies revealed that solvent effects and functional group electronic effects might influence the reaction's selectivity.

A fruitful century for the scalable synthesis and reactions of biphenyl derivatives: applications and biological aspects

This review provides recent developments in the current status and latest synthetic methodologies of biphenyl derivatives. Furthermore, this review investigates detailed discussions of several metalated chemical reactions related to biphenyl scaffolds such as Wurtz-Fittig, Ullmann, Bennett-Turner, Negishi, Kumada, Stille, Suzuki-Miyaura, Friedel-Crafts, cyanation, amination, and various electrophilic substitution reactions supported by their mechanistic pathways. Furthermore, the preconditions required for the existence of axial chirality in biaryl compounds are discussed. Furthermore, atropisomerism as a type of axial chirality in biphenyl molecules is discussed. Additionally, this review covers a wide range of biological and medicinal applications of the synthesized compounds involving patented approaches in the last decade corresponding to investigating the crucial role of the biphenyl structures in APIs.

Base-Promoted (3 + 2) Cycloaddition of Trifluoroacetohydrazonoyl Chlorides with Imidates En Route to Trifluoromethyl-1,2,4-Triazoles

A base-mediated (3 + 2) cycloaddition of trifluoroacetohydrazonoyl chlorides with imidates for the construction of 3-trifluoromethyl-1,2,4-triazoles has been described. This reaction is characterized by readily starting materials, simple reaction conditions, good yields, a broad substrate scope, and excellent regioselectivity. The utility of this protocol has been validated by the synthesis of a drug-like molecule.