53054-00-5Relevant articles and documents
One-Pot Construction of Diverse β-Lactam Scaffolds via the Green Oxidation of Amines and Its Application to the Diastereoselective Synthesis of β-Amino Acids
Yamamoto, Yuki,Kodama, Shintaro,Nishimura, Riku,Nomoto, Akihiro,Ueshima, Michio,Ogawa, Akiya
, p. 11571 - 11582 (2021/08/20)
In this study, a simple one-pot construction of β-lactam scaffolds was successfully achieved via 4,6-dihydroxysalicylic acid-catalyzed organocatalytic oxidation of amines to imines using molecular oxygen. Although some imines are highly unstable and difficult to isolate by conventional methods, the organocatalytic oxidation of amines described herein, followed by their direct reaction with acyl chlorides in the presence of a base, afforded a series of new β-lactam derivatives with excellent cis selectivity, which could not be synthesized and isolated by previously reported methods. Thus, this one-pot protocol will be one of the powerful methods applicable to the synthesis of various potential drug candidates and functional molecules. Furthermore, the subsequent hydrolysis of these β-lactams successfully afforded the corresponding β-amino acids as almost single diastereomers in up to 99% yields.
A dual biomimetic process for the selective aerobic oxidative coupling of primary amines using pyrogallol as a precatalyst. Isolation of the [5 + 2] cycloaddition redox intermediates
Deschamps, Patrick,Fleury, Maurice-Bernard,Hammad, Karim,Largeron, Martine
, p. 1894 - 1905 (2020/04/07)
A bioinspired organocatalytic cascade reaction mimicking both purpurogallin biosynthesis and copper amine oxidases (CuAOs) activity is described, at room temperature under ambient air, for the activation of the α-C-H bond of primary amines. The reaction sequence uses low-cost commercially available pyrogallol as a precatalyst which undergoes an in situ oxidative self-processing step, resulting in its conversion into natural purpurogallin, a [5 + 2] cycloaddition redox intermediate. This is further involved in the CuAOs-like transamination mechanism for producing, under single turnover, the active biomimetic organocatalyst which mediates the selective oxidative coupling of primary amines, including the non-activated substrates of CuAOs. Without any metal cocatalyst or additives, the protocol gives access to cross-coupled imines as well as 1,2-disubstituted benzimidazoles. The isolation of not easily accessible [5 + 2] cycloaddition redox intermediates provides direct and clear evidence for the proposed dual biomimetic process.
2,4,6-Trihydroxybenzoic Acid-Catalyzed Oxidative Ugi Reactions with Molecular Oxygen via Homo- And Cross-Coupling of Amines
Dong, Chun-Ping,Uematsu, Akinori,Kumazawa, Shun,Yamamoto, Yuki,Kodama, Shintaro,Nomoto, Akihiro,Ueshima, Michio,Ogawa, Akiya
, p. 11562 - 11571 (2019/10/03)
Metal-free, oxidative four-component Ugi reactions (U-4CRs) were conducted to synthesize dipeptides from two different amines, isocyanides, and carboxylic acids using 2,4,6-trihydroxybenzoic acid catalyst in O2 atmosphere. The organocatalytic U-4CRs proceed via oxidative cross-coupling of benzylamines with other aliphatic or aromatic amines to form imines, followed by condensation with isocyanides and carboxylic acids. The U-4CRs via cross-coupling of amines are rare, and the simple, metal-free procedures are advantageous for further applications in drug and heterocycle syntheses.
