Synthesis of oxazino[4,3-a]indoles by domino addition-cyclization reactions of (1H-indol-2-yl)methanols and vinyl selenones in the presence of 18-crown-6

• DOI: 10.1016/j.tet.2016.09.045
• Publication Date: 2016-09-21T23:21:32Z
• Authors: Martina Palomba; Elisa Vinti; Francesca Marini; Claudio Santi; Luana Bagnoli
• Keywords: Potassium hydroxide; Dichloromethane; Domino; Environmentally Friendly; Michael reaction; Cascade reaction

Abstract Herein we report the synthesis of biologically relevant oxazino[4,3- a ]indoles by an environmentally friendly Michael addition-cyclization cascade using potassium hydroxide in dichloromethane employing variously substituted vinyl selenones and (1 H -indol-2yl)methanols. The addition of 18-crown-6, as a complexing agent, is crucial to achieve high chemo- and regio-selectivity.