3,4-Dihydro-2H-pyran promoted aerobic oxidative aromatization of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines
作者:Dipanwita Banerjee、Utpal Kayal、Rajiv Karmakar、Gourhari Maiti
DOI:10.1016/j.tetlet.2014.07.051
日期:2014.9
An unprecedented facile oxidation of 1,3,5-trisubstituted pyrazolines and Hantzsch 1,4-dihydropyridines (DHPs) to the corresponding pyrazoles and pyridines was observed, mediated by 3,4-dihydro-2H-pyran in air. The reaction showed excellent reactivity, functional group tolerance, and high yield without using any metal and/or halogen based oxidizing agents.
观察到在空气中由3,4-二氢-2 H-吡喃介导的1,3,5-三取代的吡唑啉和Hantzsch 1,4-二氢吡啶(DHP)前所未有地容易氧化为相应的吡唑和吡啶。该反应显示出优异的反应性,官能团耐受性和高产率,而无需使用任何基于金属和/或卤素的氧化剂。