Boronic Acid Catalysis for Mild and Selective [3+2] Dipolar Cycloadditions to Unsaturated Carboxylic Acids
作者:Hongchao Zheng、Robert McDonald、Dennis G. Hall
DOI:10.1002/chem.200903484
日期:2010.5.10
activation of unsaturated carboxylic acids is applied in several classic dipolar [3+2] cycloadditions involving azides, nitrile oxides, and nitrones as partners. These cycloadditions can be used to produce pharmaceutically interesting, small heterocyclic products, such as triazoles, isoxazoles, and isoxazolidines. These cycloadducts are formed directly and include a free carboxylic acid functionality that can
The first 1,8-diheterocyclicnaphthalenes, the 1,8-bis(1′H-1′,2′,3′-triazolyl)naphthalenes (1a–i), have been synthesized by 1,3-dipolar cycloadditions of 1,8-diazidonaphthalene to acetylenic esters or enolates of acetoacetic esters, and have strained structures as revealed by comparison of their spectral properties with those of the corresponding 1-(1′H-1′,2′,3′-triazolyl)naphthalenes.