Gold(I)‐Catalysed Hydroarylation of Lactam‐Derived Enynes as an Entry to Tetrahydrobenzo[g]quinolines. Issue 6 (13th December 2019)

• Record Type: Journal Article
• Authors: Nejrotti, Stefano; Ghinato, Simone; Gini, Elena C.; Scarpi, Dina; Occhiato, Ernesto G.; Maranzana, Andrea; Prandi, Cristina
• Is Part Of: European journal of organic chemistry. Issue 6(2020)
• Page Start: 646
• Page End: 653
• Publication Date: 2019-12-13
• Subjects: Gold catalysis -- Hydroarylation -- Nitrogen heterocycles -- Benzoquinolines -- Enynes; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201901599
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : The gold(I)‐catalysed cyclization of N ‐tosyl‐protected 5‐benzyl‐6‐((trimethylsilyl)ethynyl)‐1, 2, 3, 4‐tetrahydropyridines, prepared by the Sonogashira coupling of lactam‐derived enol triflates, provides tetrahydrobenzo[ g ]quinolines whose skeleton represents a recurrent motif in natural compounds. The Au(I)‐catalysed reaction is carried out with (C6 F5 )3 PAuCl/AgNTf2 as the catalyst system and proceeds via a 6‐ exo ‐ dig cyclization to form an exocyclic double bond, which eventually isomerises to the aromatic tetrahydrobenzo[ g ]quinoline. The mode of cyclization is discussed and supported by DFT calculations. Abstract : The gold(I)‐catalysed cyclization of N ‐tosyl‐protected 5‐benzyl‐6‐((trimethylsilyl)ethynyl)‐1, 2, 3, 4‐tetrahydropyridines, prepared by Sonogashira coupling of lactam‐derived enol triflates, provides tetrahydrobenzo[ g ]quinolones. The Au(I)‐catalysed reaction is carried out with (C6 F5 )3 PAuCl/AgNTf2 and proceeds via a 6‐ exo ‐ dig cyclization to the aromatic tetrahydrobenzo[ g ]quinolines. The mode of cyclization is discussed and supported by DFT calculations.