4809-56-7Relevant articles and documents
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Watson,Youngson
, p. 2145 (1954)
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Decarboxylative cross-nucleophile coupling via ligand-to-metal charge transfer photoexcitation of Cu(ii) carboxylates
Li, Qi Yukki,Gockel, Samuel N.,Lutovsky, Grace A.,DeGlopper, Kimberly S.,Baldwin, Neil J.,Bundesmann, Mark W.,Tucker, Joseph W.,Bagley, Scott W.,Yoon, Tehshik P.
, p. 94 - 99 (2022/01/11)
Reactions that enable carbon–nitrogen, carbon–oxygen and carbon–carbon bond formation lie at the heart of synthetic chemistry. However, substrate prefunctionalization is often needed to effect such transformations without forcing reaction conditions. The development of direct coupling methods for abundant feedstock chemicals is therefore highly desirable for the rapid construction of complex molecular scaffolds. Here we report a copper-mediated, net-oxidative decarboxylative coupling of carboxylic acids with diverse nucleophiles under visible-light irradiation. Preliminary mechanistic studies suggest that the relevant chromophore in this reaction is a Cu(ii) carboxylate species assembled in situ. We propose that visible-light excitation to a ligand-to-metal charge transfer (LMCT) state results in a radical decarboxylation process that initiates the oxidative cross-coupling. The reaction is applicable to a wide variety of coupling partners, including complex drug molecules, suggesting that this strategy for cross-nucleophile coupling would facilitate rapid compound library synthesis for the discovery of new pharmaceutical agents. [Figure not available: see fulltext.].
A new generation of terminal copper nitrenes and their application in aromatic C-H amination reactions
Amarouch, Benedikt,G?bgen, Kai C.,Hoffmann, Alexander,Oster, Matthias,Sch?n, Florian,Steden, Dominik,Thomas, Fabian
supporting information, p. 6444 - 6462 (2021/05/26)
Copper nitrene complexes are highly reactive species and are known as intermediates in the copper catalyzed C-H amination. In this study, three novel copper tosyl nitrene complexes were synthesized at low temperatures, stabilized with heteroscorpionate ligands of the bis(pyrazolyl)methane family. The copper nitrenes were obtained by the reaction of a copper(i) acetonitrile complex with SPhINTs in dichloromethane. We show that the ligand design has a major influence on the catalytic activity and the thermal stability of the copper nitrene complex. Not only the choice of the third N donor, but also the substituent in the 5-position of the pyrazolyl moiety, have an impact on the stability. Furthermore, the novel copper nitrene complexes were used for catalytic aziridination of styrenes and C-H amination reactions of aromatic and aliphatic substrates under mild reaction conditions. Even challenging substrates like benzene and cyclohexane were aminated with good yields. The copper nitrene complexes were characterized using UV/Vis spectroscopy, low temperature Evans NMR spectroscopy, density functional theory, domain-based local pair natural orbital coupled cluster calculations (DLPNO-CCSD(T)) and cryo-UHR mass spectrometry.
