Silver-catalyzed acylative annulation of N-propargylated indoles with α-keto acids: access to acylated pyrrolo[1, 2-a]indoles. Issue 23 (25th February 2020)

• Record Type: Journal Article
• Authors: Reddy, Chada Raji; Kajare, Roshan Chandrakant; Punna, Nagender
• Is Part Of: Chemical communications. Volume 56:Issue 23(2020)
• Page Start: 3445
• Page End: 3448
• Publication Date: 2020-02-25
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/c9cc10069e
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : A novel carbon-centered radical cyclization of N -propargyl indoles with α-keto acids to form acylated pyrrolo[1, 2- a ]indoles involving difunctionalisation of the alkyne moiety with concomitant annulation is disclosed. Abstract : This study describes the first carbon centered radical cyclization of N -propargyl indoles involving decarboxylation of α-keto acids in the presence of an Ag-catalyst. The present cascade carbon–carbon bond formation reactions provide C -acylated pyrrolo[1, 2- a ]indoles in good yields (25 examples). The amount of oxidant has a profound effect on the reaction to convert either the di-acylated products using 8 equiv. of K2 S2 O8 or mono-acylated products using 2 equiv. of K2 S2 O8 . N -Propargyl pyrroles are also found to be suitable for delivering the corresponding 3 H -pyrrolizines.