5024-68-0Relevant articles and documents
Mediator-Enabled Electrocatalysis with Ligandless Copper for Anaerobic Chan-Lam Coupling Reactions
Walker, Benjamin R.,Manabe, Shuhei,Brusoe, Andrew T.,Sevov, Christo S.
supporting information, p. 6257 - 6265 (2021/05/07)
Simple copper salts serve as catalysts to effect C-X bond-forming reactions in some of the most utilized transformations in synthesis, including the oxidative coupling of aryl boronic acids and amines. However, these Chan-Lam coupling reactions have historically relied on chemical oxidants that limit their applicability beyond small-scale synthesis. Despite the success of replacing strong chemical oxidants with electrochemistry for a variety of metal-catalyzed processes, electrooxidative reactions with ligandless copper catalysts are plagued by slow electron-transfer kinetics, irreversible copper plating, and competitive substrate oxidation. Herein, we report the implementation of substoichiometric quantities of redox mediators to address limitations to Cu-catalyzed electrosynthesis. Mechanistic studies reveal that mediators serve multiple roles by (i) rapidly oxidizing low-valent Cu intermediates, (ii) stripping Cu metal from the cathode to regenerate the catalyst and reveal the active Pt surface for proton reduction, and (iii) providing anodic overcharge protection to prevent substrate oxidation. This strategy is applied to Chan-Lam coupling of aryl-, heteroaryl-, and alkylamines with arylboronic acids in the absence of chemical oxidants. Couplings under these electrochemical conditions occur with higher yields and shorter reaction times than conventional reactions in air and provide complementary substrate reactivity.
Sterically enriched bulky 1,3-bis(: N, N ′-aralkyl)benzimidazolium based Pd-PEPPSI complexes for Buchwald-Hartwig amination reactions
Anusha, Gokanapalli,Reddy, Motakatla Venkata Krishna,Reddy, Peddiahgari Vasu Govardhana
supporting information, p. 11694 - 11703 (2020/07/21)
Pd-PEPPSI (palladium-pyridine enhanced pre-catalyst preparation stabilization and initiation) complexes are now emerging as well-defined catalysts for C-C and C-N bond formation. In connection with this, we prepared a family of six air and moisture stable
Allyl complexes for use in coupling reactions
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Page/Page column 21; 22; 27; 28; 32, (2019/01/12)
A complex of formula (1), wherein, M is palladium or nickel, R1 and R2 are independently organic groups having 1-20 carbon atoms, or R1 and R2 are linked to form a ring structure with the phosphorus atom, R3 is selected from the group consisting of substituted and unsubstituted aryl, substituted and unsubstituted heteroaryl, and substituted and unsubstituted metallocenyl, R4 is an organic group having 1-20 carbon atoms, n is 0, 1, 2, 3, 4 or 5, X is an anionic ligand. A process for the preparation of the complex, and its use in carbon-carbon or carbon-nitrogen coupling reactions is also provided.