540-36-3Relevant articles and documents
Metal-Free Photoredox-Catalyzed Hydrodefluorination of Fluoroarenes Utilizing Amide Solvent as Reductant
Toriumi, Naoyuki,Yamashita, Kazuya,Iwasawa, Nobuharu
supporting information, p. 12635 - 12641 (2021/08/03)
A metal-free photoredox-catalyzed hydrodefluorination of fluoroarenes was achieved by using N,N,N’,N’-tetramethyl-para-phenylenediamine (1) as a strong photoreduction catalyst. This reaction was applicable not only to electron-rich monofluoroarenes but also to polyfluoroarenes to afford non-fluorinated arenes. The experimental mechanistic studies indicated that the amide solvent NMP plays an important role for regeneration of the photocatalyst, enabling additive-free photoreduction catalysis.
Nucleophilic Fluorination of Heteroaryl Chlorides and Aryl Triflates Enabled by Cooperative Catalysis
Hong, Cynthia M.,Whittaker, Aaron M.,Schultz, Danielle M.
, p. 3999 - 4006 (2021/03/09)
Aryl and heteroaryl fluorides are growing to be dominant motifs in pharmaceuticals and agrochemicals, yet they are rare in both nature and commodity chemicals. As a consequence, there is an increasingly urgent need to develop mild, cost-effective, and scalable methods for fluorination. The most straightforward route to synthesize aryl fluorides is through the halide exchange "halex"reaction, but conditions, cost, and atom economy preclude most available methods from large-scale manufacturing processes. We report a new approach that leverages the cooperative action of 18-crown-6 ether and tetramethylammonium chloride to catalytically access the reactivity of tetramethylammonium fluoride and achieve halex fluorinations under mild conditions with operational ease. The described methodology readily converts both heteroaryl chlorides and aryl triflates to their corresponding (hetero)aryl fluorides in high yields and purities.
Fluorination of arylboronic esters enabled by bismuth redox catalysis
Planas, Oriol,Wang, Feng,Leutzsch, Markus,Cornella, Josep
, p. 313 - 317 (2020/01/28)
Bismuth catalysis has traditionally relied on the Lewis acidic properties of the element in a fixed oxidation state. In this paper, we report a series of bismuth complexes that can undergo oxidative addition, reductive elimination, and transmetallation in a manner akin to transition metals. Rational ligand optimization featuring a sulfoximine moiety produced an active catalyst for the fluorination of aryl boronic esters through a bismuth (III)/bismuth (V) redox cycle. Crystallographic characterization of the different bismuth species involved, together with a mechanistic investigation of the carbonfluorine bond-forming event, identified the crucial features that were combined to implement the full catalytic cycle.