Carbon monoxide as a reductant: synthesis of indoles by palladium catalyzed reductive cyclization of beta-nitrostyrenes

التفاصيل البيبلوغرافية
العنوان: Carbon monoxide as a reductant: synthesis of indoles by palladium catalyzed reductive cyclization of beta-nitrostyrenes
المؤلفون: M. Elatawy, F. Ferretti, D. Formenti, F. Ragaini, M. Hagar, S. Muto
المساهمون: M. Elatawy, M. Hagar, F. Ferretti, D. Formenti, S. Muto, F. Ragaini
سنة النشر: 2013
المجموعة: The University of Milan: Archivio Istituzionale della Ricerca (AIR)
مصطلحات موضوعية: indole, reductive carbonylation, palladium catalysis, Settore CHIM/03 - Chimica Generale e Inorganica
الوصف: Several years ago, while investigating the possibility to use beta-nitrostyrenes as aminating agents for olefins following our protocol originally devised for nitroarenes, we found that a cyclization reaction to give indoles was observed instead. Better results were obtained employing palladium as catalyst in place of ruthenium. The reaction conditions were optimized using beta-methyl-beta-nitrostyrene (1a) as substrate and some results with different substrates are reported below. While our work was in progress, Hsieh and Dong reported a similar approach for the synthesis of 3-arylsubstituted indoles from alpha-aryl-beta-nitrostyrenes (R1= H, R2 = Ar in the scheme above). Experimental conditions reported in that paper are milder (100 °C, DMF, 2 bar CO absolute pressure) then ours. We reproduced those results and we confirm they work well for alpha-aryl-beta-nitrostyrenes, but fail almost completely when R1 is not H, whereas our conditions are suitable also in this case. Unlike most reported cyclization reaction affording indoles, our strategy does not require the use of a doubly functionalized arene (e.g. an o-bromoaniline) and in most cases the starting materials can be easily prepared by a Henry reaction.
نوع الوثيقة: conference object
اللغة: English
Relation: Sigma Aldrich Young Chemists Symposium; http://hdl.handle.net/2434/249311
الاتاحة: http://hdl.handle.net/2434/249311
Rights: info:eu-repo/semantics/openAccess
رقم الانضمام: edsbas.BCA852B3
قاعدة البيانات: BASE