65608-83-5Relevant articles and documents
Synthesis of Benzoisoselenazolones via Rh(III)-Catalyzed Direct Annulative Selenation by Using Elemental Selenium
Xu-Xu, Qing-Feng,Nishii, Yuji,Uetake, Yuta,Sakurai, Hidehiro,Miura, Masahiro
supporting information, p. 17952 - 17959 (2021/11/16)
Isoselenazolone derivatives have attracted significant research interest because of their potent therapeutic activities and indispensable applications in organic synthesis. Efficient construction of functionalized isoselenazolone scaffolds is still challenging, and thus new synthetic approaches with improved operational simplicity have been of particular interest. In this manuscript, we introduce a rhodium-catalyzed direct selenium annulation by using stable and tractable elemental selenium. A series of benzamides as well as acrylamides were successfully coupled with selenium under mild reaction conditions, and the obtained isoselenazolones could be pivotal synthetic precursors for several organoselenium compounds. Based on the designed control experiments and X-ray absorption spectroscopy measurements, we propose an unprecedented selenation mechanism involving a highly electrophilic Se(IV) species as the reactive selenium donor. The reaction mechanism was further verified by a computational study.
Half-Sandwich Ruthenium Complexes Bearing Hemilabile κ2-(C,S)?Thioether-Functionalized NHC Ligands: Application to Amide Synthesis from Alcohol and Amine
Achard, Thierry,Bellemin-Laponnaz, Stéphane,Chen, Weighang,Egly, Julien,Maisse-Fran?ois, Aline
supporting information, (2022/01/20)
Amide synthesis is one of the most crucial transformations in chemistry and biology. Among various catalytic systems, N-heterocyclic carbene (NHC)-based ruthenium (Ru) catalyst systems have been proven to be active for direct synthesis of amides by sustainable acceptorless dehydrogenative Coupling of primary alcohols with amines. Most often, these catalytic systems usually use monodentate NHC and thus require an additional ligand to obtain high reactivity and selectivity. In this work, a series of cationic Ru(II)(η6-p-cymene) complexes with thioether-functionalized N-heterocyclic carbene ligands (imidazole and benzimidazole-based) have been prepared and fully characterized. These complexes have then been used in the amidation reaction and the most promising one (i. e. 3 c) has been applied on a large range of substrates. High conversions albeit with moderate yields have generally been obtained.
Atom Transfer Radical Polymerization-Inspired Room Temperature (sp3)C-N Coupling
Coote, Michelle L.,Fung, Alfred. K. K.,Sherburn, Michael S.,Yu, Li-Juan
, p. 9723 - 9732 (2021/07/20)
A simple nonphotochemical procedure is reported for Cu(I)-catalyzed C-N coupling of aliphatic halides with amines and amides. The process is loosely based on the Goldberg reaction but takes place readily at room temperature. It uses Cu(I)Br, a commonly used and inexpensive atom transfer radical polymerization precatalyst, along with the cheap ligand N,N,N′,N″,N″-pentamethyldiethylenetriamine, to activate the R-X bond of the substrate via inner-sphere electron transfer. The procedure brings about productive C-N bond formation between a range of alkyl halide substrates with heterocyclic aromatic amines and amides. The mechanism of the coupling step, which was elucidated through application of computational methods, proceeds via a unique Cu(I) → Cu(II) → Cu(III) → Cu(I) catalytic cycle, involving (a) inner-sphere electron transfer from Cu(I) to the alkyl halide to generate the alkyl radical; (b) successive coordination of the N-nucleophile and the radical to Cu(II); and finally reductive elimination. In the absence of a nucleophile, debrominative homocoupling of the alkyl halide occurs. Control experiments rule out SN-type mechanisms for C-N bond formation.
