Synthesis of 5,6-Dihydro-4H-pyrrolo[1,2-b]pyrazoles and Homologs from 5-Substituted 2-(Alkynyl)tetrazoles via Microwave-Induced Intramolecular Nitrile-Imine–Alkyne 1,3-Dipolar Cycloaddition
A simple, green and efficient method has been developed for the synthesis of 5-substituted 1H-tetrazole derivatives through [2+3] cycloaddition reaction in good to excellent yields between various benzonitriles and sodium azide. For this purpose, 1-disulfo-[2,2-bipyridine]-1,1-diium chloride ([BiPy](HSO3)2Cl2) system as an ionicliquidcatalyst have been extended for the construction of these valuable
Catalytic conversion of 2,4,5-trisubstituted imidazole and 5-substituted 1H-tetrazole derivatives using a new series of half-sandwich (η6-p-cymene)Ruthenium(II) complexes with thiophene-2-carboxylic acid hydrazone ligands
作者:Govindasamy Vinoth、Sekar Indira、Madheswaran Bharathi、Govindhasamy Archana、Luis G. Alves、Ana M. Martins、Kuppannan Shanmuga Bharathi
DOI:10.1016/j.ica.2020.120089
日期:2021.2
The molecular structures of the ruthenium(II) complexes 1-3 were determined by single-crystal X-ray diffraction. All complexes were used as catalysts for the one-pot three-component syntheses of 2,4,5-trisubstitued imidazole and 5-substituted 1H-tetrazole derivatives. The catalytic studies optimized parameters as solvent, temperature and catalyst. The catalysts revealed very active for a broad range
摘要一系列新的半三明治(η6-对-cymene)钌(II)与噻吩-2-羧酸酰肼衍生物[Ru(η6-对-cymene)(Cl)(L)] [L = N' -(萘-1-基亚甲基)噻吩-2-碳酰肼(L1),N'-(蒽-9-基亚甲基)噻吩-2-碳酰肼(L2)和N'-(吡喃-1-基亚甲基)噻吩-2-合成了碳酰肼(L3)]。通过光谱(IR,UV-Vis,NMR和质谱)和元素分析对配体前体及其Ru(II)配合物(1-3)进行结构表征。钌(II)配合物1-3的分子结构通过单晶X射线衍射测定。所有配合物均用作催化剂,用于一锅三组分合成2,4,5-三取代的咪唑和5-取代的1H-四唑衍生物。催化研究优化了溶剂,温度和催化剂等参数。所述催化剂显示出对具有电子吸引子或电子给体取代基的广泛范围的芳族醛非常有效,并且尽管活性较低,但对于烷基醛观察到中等至高的活性。
Indium(III) Chloride Catalyzed Synthesis of 5-Substituted 1H-Tetrazoles from Oximes and Sodium Azide
A simple and efficient protocol has been developed for the synthesis of 5-substituted 1H-tetrazole derivatives in good to excellent yields from various oximes and sodium azide by using indium(III) chloride as a Lewis acid catalyst. The present method has significant advantages, such as an inexpensive catalyst, low catalyst loading, mild reaction conditions, and simple experimental procedures.
Lithiation Substitution of Unprotected Benzyltetrazoles
作者:Jeff Y. F. Wong、Agnieszka Lewandowska、Benjamin R. Trowse、Graeme Barker
DOI:10.1021/acs.orglett.9b02633
日期:2019.9.6
N-alkyl-protecting group, precluding the products from use as carboxylate bioisosteres, the major role of tetrazoles in pharmaceuticals. We herein report a convenient, protecting-group-free lithiation-substitution protocol for benzylic tetrazoles. Metalation with n-BuLi at 0 °C followed by electrophilic trapping gave a range of α-functionalized benzyltetrazoles in up to 91% yield.
A novel method for the synthesis of 5-substituted 1H-tetrazole from oxime and sodium azide
作者:Umakant B. Patil、Kedar R. Kumthekar、Jayashree M. Nagarkar
DOI:10.1016/j.tetlet.2012.04.093
日期:2012.7
A simple and efficient protocol is developed for the synthesis of 5-substituted 1H-tetrazoles from various oximes and sodiumazide (NaN3) by using copper acetate as a catalyst.