Iron-Catalyzed Oxidative Tandem Reactions with TEMPO Oxoammonium Salts: Synthesis of Dihydroquinazolines and Quinolines

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• 作者：Renate Rohlmann ; Tobias Stopka ; Heinrich Richter ; Olga Garcı ; &#769 ; a Manche帽o
• 刊名：The Journal of Organic Chemistry
• 出版年：2013
• 出版时间：June 21, 2013
• 年：2013
• 卷：78
• 期：12
• 页码：6050-6064
• 全文大小：696K
• 年卷期：v.78,no.12(June 21, 2013)
• ISSN：1520-6904

文摘

A straightforward iron-catalyzed divergent oxidative tandem synthesis of dihydroquinazolines and quinolines from N-alkylanilines using a TEMPO oxoammonium salt as a mild and nontoxic oxidant has been developed. Fe(OTf)₂ was the Lewis acid catalyst of choice for the formation of dihydroquinazolines, whereas FeCl₃ led to better results for the synthesis of quinolines. This divergent approach implies that, for both syntheses, direct oxidative functionalization of a 伪-C(sp³)鈥揌 bond of the N-alkylanilines occurs, leading to C鈥揘 bond formation or C鈥揅 bond formation upon homocondensation or reaction with simple olefins, respectively. Cyclization followed by a final oxidation generates these classes of interesting bioactive heterocycles in one synthetic transformation. Additionally, the one-pot multicomponent synthesis of quinolines from anilines, aldehydes, and olefins has also been successfully developed under these mild oxidative conditions.