Preparation and Cycloaddition Reactions of Enantiopure 2-(N-Acylamino)-1,3-dienes for the Synthesis of Octahydroquinoline Derivatives

• Published in: Journal of organic chemistry Vol. 68; no. 16; pp. 6360 - 6368
• Main Authors: Galbo, Fabrizio Lo, Occhiato, Ernesto G, Guarna, Antonio, Faggi, Cristina
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 08.08.2003; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; CROSS-COUPLING REACTIONS; ASYMMETRIC-SYNTHESIS; VINYL PHOSPHATES; ACETYLENE; VINYLBORONATE ESTER; REACTIVITY; ARYL; HETEROARYL BORONIC ACIDS; ENANTIOSELECTIVE TOTAL-SYNTHESIS; CYCLIZATION; Regioselectivity; Nitrogen heterocycle; Lactam; Quinoline derivatives; Diels Alder addition; Dienic compound; Pyridine derivatives; Imide; Chiral auxiliary; Cycloaddition; Bicyclic compound; Organic phosphate; Chemical synthesis; Boronic acids; Ethylenic compound
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo0344687

Stille, Suzuki−Miyaura, and Sonogashira cross-coupling reactions were carried out with a glutarimide-derived vinyl phosphate, bearing a chiral auxiliary on the N atom, to prepare enantiopure 2-(N-acylamino)-1,3-dienes as partners in Diels−Alder reactions. The cycloadditions were performed with various dienophiles under thermal conditions, with or without Lewis acids. With maleimides, the preferential formation of endo cycloadducts was observed, whereas with acrylamides the exo approach prevailed. Furthermore, in the latter case, 6-substitued octahydroquinolinones were obtained in accordance with the predicted regioselectivity. Since diastereopure compounds were in all cases obtained either by chromatography or by crystallization, and because of the easy access to a variety of boronic acids, to be used in the coupling step, this methodology is useful for the short synthesis of differently substituted, enantiopure octahydroquinolinones amenable to further transformation into decahydroquinolines possessing interesting biological activities.