Recent Developments in Transition Metal‐Catalyzed Cross‐Dehydrogenative Coupling Reactions of Ethers and Thioethers

Abstract

dehydrogenative coupling of two CÀH bonds or a CÀH and an XÀH bond (X=N, O, P, S, etc.) has emerged as a powerful new synthetic methodology in the last 12 years. Using this approach, simple ethers, often utilized as solvents, and more complex ones, as well as thioethers, have become important alkylating agents, when reacted directly, under oxidative conditions in the presence of suitable reagents. This environmentally friendly, sustainable procedure, has been used to alkylate a wide range of substrates, from simple ketones and acids to alkyl benzenes, coumarins, indoles, oxazoles, benzoxazoles or (benzo)thiazoles and more. This Review is a systematic presentation of the developments in transition metal-catalyzed CDC reactions, including photoredox processes, which took place between 2014 and early 2018, with an emphasis on the later years.

Oxidative Dearomative Cross-Dehydrogenative Coupling of Indoles with Diverse C-H Nucleophiles: Efficient Approach to 2,2-Disubstituted Indolin-3-ones

“…Direct C-H functionalization has emerged as an elegant approach to the construction of C-C bonds [1][2][3][4][5][6][7]. Particularly, oxidative cross-dehydrogenative coupling (CDC) from two readily available C-H bonds features the advantage of high step-and atom-economy, as it does not require pre-functionalized substrates [8][9][10][11][12]. Over the past decades, oxidative CDC reactions have gained tremendous attention since the pioneering work of Li, and numerous oxidative systems have been successfully developed [13][14][15][16][17][18].…”

Combustion-Synthesized Porous CuO-CeO2-SiO2 Composites as Solid Catalysts for the Alkenylation of C(sp3)-H Bonds Adjacent to a Heteroatom via Cross-Dehydrogenative Coupling

“…Interestingly, the reaction of N-methyl-2-pyrrolidone with 1,1-diphenylethylene showed high selectivity to the cyclic C(sp 3 )-H bond, giving 5-(2,2-diphenylvinyl)-1-methylpyrrolidin-2-one (65%, Entry 3) while a much lower yield of 30% was obtained for the case of N,Ndimethylacetamide. Coumarin-based compounds exhibit a wide range of biological activities and applications; therefore, in order to expand the substrate scope, the reactivity of the coumarins in this catalytic cross-dehydrogenative route was investigated [9,91,92]. Under the identical conditions, it was found that the C 3 position of coumarin could be directly functionalized with tetrahydrofuran and dimethylacetamide with yields of 28 and 58%, respectively.…”

“…The CDC for the α-functionalization of ethers and amines is still a grand challenge because of the inert and ubiquitous nature of the C(sp 3 )-H bond. Many efforts to expand this convenient method have been reported in the past decade, in which first-row transition metals, namely copper, iron, cobalt, are the most used catalysts [6,[9][10][11][12]. Liu and co-workers investigated the α-functionalization of ethers with olefins in the presence of CuI catalyst to obtain α-alkenylated ethers [13].…”

Société Chimique de France Prizes 2018: J. A. Baceiredo, P. Samorì, P. Knochel, Z. Shuai, F. Lloret Pastor, A. J. L. Pombeiro / Sir William Grove Award: P. Strasser / Jaroslav Heyrovsky Prize: S. Waldvogel

“…Pombeiro's research program includings topics such as the activation of small molecules and design of new catalysts for sustainable synthesis and catalysis, as well as crystal engineering of coordination compounds and self‐assembly of polynuclear and supramolecular structures. He is co‐author of a Review in ChemCatChem on transition‐metal‐catalyzed cross‐dehydrogenative coupling reactions, and in ChemistrySelect on solvent‐free Friedel–Crafts benzoylation and acylation reactions . Pombeiro has also co‐edited books on topics such as noncovalent interactions and functionalization of alkanes…”