The Michael addition of indoles to α, β-unsaturated ketones catalyzed by CeCl3.7H2O-NaI combination supported on silica gel

• 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: Washington, DC American Chemical Society 30.05.2003
• Subjects: Chemistry; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with only one n hetero atom and condensed derivatives; Organic chemistry; Preparations and properties; Michael addition; Catalytic reaction; Nitrogen heterocycle; Sodium Iodides; Cerium III Chlorides; Solid phase; Indole derivatives; Chemical synthesis; Ketone; Enone; Alkylation
• ISSN: 0022-3263
• 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 alpha,beta-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.