Recent Advances in Transition Metal–Catalyzed Csp2-X (X = S, N, O) Cross-Coupling Reactions in Water

Abstract

Thioethers, amines, and ethers represent the key compounds finding application throughout life and material sciences. In this vein, transition metal–catalyzed Csp2-S, Csp2-N, and Csp2-O cross-couplings provide an influential synthetic tool and serve as an imperative toolbox for the edifice of above privileged compounds from laboratory to industrial scale. These reactions are significantly discovered in organic and halogenated solvents, thereby posing health and environmental hazards. Lately, efforts are thus being made toward the utilization of more sustainable solvents for the above purpose. Contextually, the use of water has witnessed noteworthy attention over the past couple of decades, thereby allowing for substantial chemical waste reduction. This review summarizes the recent advances (2008–July 2025) in transition metal–catalyzed cross-coupling reactions for the synthesis of thioethers, amines, and ethers via Csp2-S, Csp2-N, and Csp2-O bond formation in aqueous media. The discussed transformations are organized according to the nucleophilic coupling partners, sulfur, nitrogen, and oxygen, reacting with aryl halides and related electrophiles.