The Michael Addition of Indoles to α,β-Unsaturated Ketones Catalyzed by CeCl3·7H2O−NaI Combination Supported on Silica Gel1

• Published in: Journal of organic chemistry Vol. 68; no. 11; pp. 4594 - 4597
• Main Authors: Bartoli, Giuseppe, Bartolacci, Massimo, Bosco, Marcella, Foglia, Gioia, Giuliani, Arianna, Marcantoni, Enrico, Sambri, Letizia, Torregiani, Elisabetta
• Format: Journal Article
• Language: English
• Published: American Chemical Society 30.05.2003
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo034303y

Alkylation of indoles by means of the Michael addition has been the subject of a number of investigation. It is well established that regioselectivity in the additions of indoles to electron-deficient alkenes is strongly controlled by the reaction medium. In a continuation of the work on developing greener and cleaner technologies, the cerium(III) chloride heptahydrate and sodium iodide combination supported on silica gel catalyzes the alkylation of various indoles with α,β-unsaturated ketones giving 3-(3-oxoalkyl)indole derivatives in good yields. The substitution on the indole nucleus occurred exclusively at the 3-position, and N-alkylation products have not been observed.