2579-22-8Relevant articles and documents
P-Stereogenic Phosphines Directed Copper(I)-Catalyzed Enantioselective 1,3-Dipolar Cycloadditions
Gan, Zhenjie,Zhi, Mengna,Han, Ruiping,Li, Er-Qing,Duan, Zheng,Mathey, Fran?ois
, p. 2782 - 2785 (2019)
A new pair of P-stereogenic ligands with multiple chiral centers were synthesized and used in the copper(I)-catalyzed enatioselective [3 + 2] cycloaddition of iminoesters with alkenes. A variety of highly functionalized pyrrolidines were obtained in excellent yield and enatioselectivity. This is the first example of a pair of P-stereogenic ligands working as pseudoenantiomers to tune the enantio- and diastereoselective 1,3-dipolar cycloaddition, and providing a pair of enantiomerically pure pyrrolidines, respectively.
Copper-catalyzed TEMPO addition to propargyl alcohols for the synthesis of vinylic alkoxyamines
Kang, Ye-Won,Choi, Yoon-Jeong,Jang, Hye-Young
, p. 4842 - 4845 (2014)
A variety of vinylic alkoxyamines derived from propargyl alcohols and 2, 2, 6,6-tetramethylpiperidine N-oxyl (TEMPO) were synthesized in good yields under copper-catalyzed aerobic conditions. A reaction mechanism was proposed, involving the isomerization of propargyl radicals to allenic radicals, and related mechanistic studies were performed. The kinetic isotope effect on the propargyl C-H bond cleavage (α-deprotonation) reaction was observed (kH/kD = 3.76).
Highly efficient and mild synthesis of variously 5-substituted-4-carbaldehyde-1,2,3-triazole derivatives
Journet, Michel,Cai, Dongwei,Kowal, Jason J.,Larsen, Robert D.
, p. 9117 - 9118 (2001)
Synthesis of variously 5-substituted-4-carbaldehyde-1,2,3-triazole derivatives 2 was accomplished by reacting sodium azide with α,β-acetylenic aldehydes 1 in DMSO at room temperature. Therefore, the reaction remains basic avoiding the generation of the hazardous explosive HN3, resulting in a safe process. This mild and general reaction was instantaneous and was essentially quantitative.
Synthesis of 1,3-dioxacyclan-2-yl-substituted 1,2,3-triazoles
Zlotskii,Raskil’dina,Golovanov,Bormotin,Bekin
, p. 3 - 6 (2017)
A new method for preparing 4-(1,3-dioxacyclan-2-yl)-5-phenyl-1,2,3-triazoles in 30–75% yields has been developed on the basis of azide–alkyne cycloaddition to 2-phenylethinyl-1,3-dioxacyclanes. It has been shown that the best results are achieved when the reaction is carried out at 150–155°C in DMSO.
Controlled reduction of activated primary and secondary amides into aldehydes with diisobutylaluminum hydride
Azeez, Sadaf,Kandasamy, Jeyakumar,Sabiah, Shahulhameed,Sureshbabu, Popuri
supporting information, p. 2048 - 2053 (2022/03/31)
A practical method is disclosed for the reduction of activated primary and secondary amides into aldehydes using diisobutylaluminum hydride (DIBAL-H) in toluene. A wide range of aryl and alkyl N-Boc, N,N-diBoc and N-tosyl amides were converted into the corresponding aldehydes in good to excellent yields. Reduction susceptible functional groups such as nitro, cyano, alkene and alkyne groups were found to be stable. Broad substrate scope, functional group compatibility and quick conversions are the salient features of this methodology.
Visible Light-Induced Cascade Cyclization of 3-Aminoindazoles, Ynals, and Chalcogens: Access to Chalcogen-Containing Pyrimido[1,2- b]-indazoles
Zhou, Jinlei,Li, Wen,Zheng, Huitao,Pei, Yongyan,Liu, Xiang,Cao, Hua
supporting information, p. 2754 - 2759 (2021/04/12)
A direct cascade cyclization of 3-aminoindazoles, ynals, and accessible chalcogens facilitated by visible light has been developed. A series of fluoroactive selenium/tellurium-substituted pyrimido[1,2-b]-indazoles were easily accessed in moderate to good yields with a broad scope. Furthermore, we surveyed the spectral properties of selenide pyrimido[1,2-b]-indazoles prepared by this method.
A new catalytic approach for aerobic oxidation of primary alcohols based on a Copper(I)-thiophene carbaldimines
Lagerspets, Emi,Valbonetti, Evelyn,Eronen, Aleksi,Repo, Timo
, (2021/06/03)
We report here novel Cu(I) thiophene carbaldimine catalysts for the selective aerobic oxidation of primary alcohols to their corresponding aldehydes and various diols to lactones or lactols. In the presence of the in situ generated Cu(I) species, a persistent radical (2,2,6,6-tetramethylpiperdine-N-oxyl (TEMPO)) and N-methylimidazole (NMI) as an auxiliary ligand, the reaction proceeds under aerobic conditions and at ambient temperature. Especially the catalytic system of 1-(thiophen-2-yl)-N-(4-(trifluoromethoxy)phenyl)methanimine (ligand L2) with copper(I)-iodide showed high reactivity for all kind of alcohols (benzylic, allylic and aliphatic). In the case of benzyl alcohol even 2.5 mol% of copper loading gave quantitative yield. Beside high activity under aerobic conditions, the catalysts ability to oxidize 1,5-pentadiol to the corresponding lactol (86% in 4 h) and N-phenyldiethanolamine to the corresponding morpholine derivate lactol (86% in 24 h) is particularly noteworthy.