Synthesis of Carbolines via Microwave‐Assisted Cadogan Reactions of Aryl‐Nitropyridines. Issue 1 (4th January 2018)

• Record Type: Journal Article
• Authors: Limbach, Daniel; Geffe, Mario; Detert, Heiner
• Is Part Of: ChemistrySelect. Volume 3:Issue 1(2018)
• Page Start: 249
• Page End: 252
• Publication Date: 2018-01-04
• Subjects: alkaloids -- carbolines -- heterocycles -- microwave chemistry -- phosphorus; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/slct.201702964
• Languages: English
• ISSNs: 2365-6549

Abstract

Abstract: Suzuki‐Miyaura‐couplings to aryl‐nitropyridines followed by Cadogan reactions is a straight‐forward method for the synthesis of δ‐ and β‐carbolines. Microwave irradiation of the nitrobiaryls in triethyl phosphite solutions conveniently gives moderate to very good yields of the carbolines. Reduction to the amines without cyclization occurs on certain substrates, and alkylation of the products is observed as a follow‐up reaction. Instead of α‐carbolines, naphthonitriles are generated by phosphite reduction and ring transformation. Abstract : Suzuki‐Miyaura couplings to aryl‐nitropyridines followed by Cadogan reactions is a straight‐forward method for the synthesis of δ‐ and β‐carbolines. Instead of α‐carbolines, this route produces naphthonitriles. Microwave irradiation of the nitrobiaryls in triethyl phosphite solutions conveniently gives moderate to very good yields of the carbolines. Reductions to the amines without cyclization occurs with certain substrates, and alkylation of the products can be a follow‐up reaction.