5958-02-1Relevant academic research and scientific papers
5,6- and 6,6-Membered Palladium(II) Pincer Complexes Based on Functionalized Carboxamides with Ancillary Sulfur and Nitrogen Donors
Churusova, Svetlana G.,Aleksanyan, Diana V.,Vasil'ev, Andrei A.,Nelyubina, Yulia V.,Novikov, Valentin V.,Pavlov, Alexander A.,Denisov, Gleb L.,Klemenkova, Zinaida S.,Kozlov, Vladimir A.
, p. 5271 - 5280 (2016)
New multidentate ligands have been synthesized by the condensation of 2-(methylsulfanyl)benzoyl chloride with a range of amines bearing ancillary N or S donors. In reactions with PdCl2(NCPh)2, the ligands smoothly underwent direct cyclopalladation to give pincer complexes with 5,6- or 6,6-membered fused metallocycles. The oxidation of the sulfide ligands with H2O2afforded the corresponding sulfoxide derivatives, which readily formed analogous pincer complexes with the PdIIions. The realization of κ3-S,N,X coordination (X = N or S) was confirmed by multinuclear NMR and IR spectroscopic data and, in some cases, X-ray crystallography. An unusual dynamic behavior of the 6,6-membered S,N,S complex with an organophosphorus ligand was additionally studied by the ROESY technique. All of the palladocycles obtained were tested as precatalysts for the Suzuki cross-coupling of aryl bromides with arylboronic acids, which allowed us to evaluate the main structure–activity relationships.
Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
, p. 208 - 218 (2021/12/29)
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
Decarbonylative Pd-Catalyzed Suzuki Cross-Coupling for the Synthesis of Structurally Diverse Heterobiaryls
Blakemore, David C.,Cervantes-Reyes, Alejandro,Chinigo, Gary M.,Smith, Aaron C.,Szostak, Michal
supporting information, p. 1678 - 1683 (2022/03/14)
Heteroaromatic biaryls are core scaffolds found in a plethora of pharmaceuticals; however, their direct synthesis by the Suzuki cross-coupling is limited to heteroaromatic halide starting materials. Here, we report a direct synthesis of diverse nitrogen-containing heteroaromatic biaryls by Pd-catalyzed decarbonylative Suzuki cross-coupling of widely available heterocyclic carboxylic acids with arylboronic acids. The practical and modular nature of this cross-coupling enabled the straightforward preparation of >45 heterobiaryl products using pyridines, pyrimidines, pyrazines, and quinolines in excellent yields. We anticipate that the modular nature of this protocol will find broad application in medicinal chemistry and drug discovery research.
Complexes LNi(Cp)X with alkylamino-substituted N-heterocyclic carbene ligands (L) and their catalytic activity in the Suzuki—Miyaura reaction
Chernyshev, V. M.,Chesnokov, V. V.,Shevchenko, M. A.,Soliev, S. B.,Tafeenko, V. A.
, p. 1281 - 1289 (2021/08/10)
New nickel(ii) complexes of the general formula LNi(Cp)X (L is an N-heterocyclic carbene (NHC) ligand of the 1,2,4-triazole or imidazole series; Cp is the cyclopentadienyl anion; X = Cl, I) are reported. In these complexes, the NHC ligands (L) contain an alkylamino group at the 3 or 4 position of the heterocycle. The synthesized complexes and structurally similar complexes without an alkylamino group were tested for catalytic activity in the Suzuki—Miyaura reaction. The introduction of an alkylamino group into the NHC ligand leads to the enhancement of the catalytic activity of complexes with N,N′-diaryl-substituted NHC ligands of the imidazole series and a decrease in the activity of the complexes with N,N′-dialkyl-substituted NHC ligands of the 1,2,4-triazole series.
Organozinc-mediated direct cross-coupling under microwave irradiation
Li, Chun-Jing
, p. 869 - 875 (2021/07/02)
We report a direct cross-coupling reaction between (het)aryl pivalates/tosylates and di(het)arylzinc species in 2-methyltetrahydrofuran/N-methyl pyrrolidone (1:1), which occurs via C–O bond cleavage under microwave irradiation. The reaction takes place smoothly in short reaction times without the addition of any catalyst or ligand. The reaction is suitable for a broad scope of substrates and exhibits good functional group compatibility, utilizes a simple work-up procedure, and gives the desired products in high purity.
A general palladium-catalyzed cross-coupling of aryl fluorides and organotitanium (IV) reagents
He, Xiao-Yun
, p. 823 - 832 (2021/07/19)
Pd(OAc)2/1-[2-(di-tert-butylphosphanyl)phenyl]-4-methoxy-piperidine was demonstrated to effectively catalyze cross-coupling of aryl fluoride and aryl(alkyl) titanium reagent. Both electron-deficient and electron-rich aryl fluoride can react effectively with nucleophile and provide extensive functional groups tolerance. 2-Arylated product was realized by selective activation of the C–F bond. Graphic abstract: [Figure not available: see fulltext.].
Pd- And Ni-Based Systems for the Catalytic Borylation of Aryl (Pseudo)halides with B2(OH)4
Munteanu, Charissa,Spiller, Taylor E.,Qiu, Jun,Delmonte, Albert J.,Wisniewski, Steven R.,Simmons, Eric M.,Frantz, Doug E.
, p. 10334 - 10349 (2020/09/18)
Despite recent advancements in metal-catalyzed borylations of aryl (pseudo)halides, there is a continuing need to develop robust methods to access both early-stage and late-stage organoboron intermediates amendable for further functionalization. In particular, the development of general catalytic systems that operate under mild reaction conditions across a broad range of electrophilic partners remains elusive. Herein, we report the development and application of three catalytic systems (two Pd-based and one Ni-based) for the direct borylation of aryl (pseudo)halides using tetrahydroxydiboron (B2(OH)4). For the Pd-based catalyst systems, we have identified general reaction conditions that allow for the sequestration of halide ions through simple precipitation that results in catalyst loadings as low as 0.01 mol % (100 ppm) and reaction temperatures as low as room temperature. We also describe a complementary Ni-based catalyst system that employs simple unligated Ni(II) salts as an inexpensive alternative to the Pd-based systems for the borylation of aryl (pseudo)halides. Extrapolation of all three systems to a one-pot tandem borylation/Suzuki-Miyaura cross-coupling is also demonstrated on advanced intermediates and drug substances.
A highly efficient and recyclable NiCl2(dppp)/PEG-400 system for Suzuki-Miyaura reaction of aryl chlorides with arylboronic acids
Liao, Yang,Yang, Weisen,Wei, Ting,Cai, Mingzhong
supporting information, p. 1134 - 1142 (2019/04/10)
NiCl2(dppp) in PEG-400 is shown to be a highly efficient catalyst for Suzuki-Miyaura coupling of aryl chlorides with arylboronic acids. The reaction could be conducted at 100 °C using K3PO4 as base, yielding a variety of biaryls in good to excellent yields. The isolation of the products was readily performed by extraction with petroleum ether and NiCl2(dppp)/PEG-400 system could be easily recycled and reused up to five times without significant loss of activity. Our system not only avoids the use of easily volatile and toxic dioxane or toluene as a solvent but also solves the basic problem of nickel catalyst reuse.
Room-Temperature Aqueous Suzuki-Miyaura Cross-Coupling Reactions Catalyzed via a Recyclable Palladium@Halloysite Nanocomposite
Hamdi, Jumanah,Blanco, Alexis A.,Diehl, Brooke,Wiley, John B.,Trudell, Mark L.
supporting information, p. 3471 - 3475 (2019/04/25)
A reliable method for encapsulation of palladium nanoparticles (6-8 nm particles) in halloysite (Pd@Hal) has been developed. The Pd@Hal was found to be a highly efficient room-temperature catalyst for Suzuki-Miyaura cross-coupling reactions that gave high yields of a diverse array of coupling products in 5:2 n-PrOH/H2O within 1 h. The catalytic system was remarkably effective with a broad substrate scope. In addition, the catalyst was easily recovered and recycled without a significant loss of catalytic activity.
SUBSTITUTED METHYL PYRAZOLOPYRIMIDINONE AND METHYL IMIDAZOPYRAZINONE COMPOUNDS AS PDE1 INHIBITORS
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Paragraph 0556, (2019/06/20)
A chemical entity of Formula (I) or Formula (II): wherein Ra, Rb, Re, and Rf have any of the values described herein, and compositions comprising such chemical entities; methods of making them; and their use in
