Palladium-Mediated Oxidative Annulation of delta-Indolyl-alpha,beta-Unsaturated Compounds toward the Synthesis of Cyclopenta[b]indoles and Heterogeneous Hydrogenation To Access Fused Indolines

Author(s)

Agy, Andre Capretz ^[1] ; Rodrigues, Jr., Manoel T. ^[1] ; Zeoly, Lucas A. ^[1] ; Simoni, Deborah A. ^[2] ; Coelho, Fernando ^[1]

Affiliation

^[1] Univ Estadual Campinas, Lab Synth Nat Prod & Drugs, POB 6154, BR-13083979 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Lab Crystallog, Inst Chem, POB 6154, BR-13083979 Campinas, SP - Brazil

• Document type: Journal article
• Source: Journal of Organic Chemistry; v. 84, n. 9, p. 5564-5581, MAY 3 2019.
• Web of Science Citations: 4

Abstract

The cyclopenta{[}b]indole moiety represents a key skeletal unit in several natural and synthetic compounds that exhibit diverse biological properties. We described herein a two-step sequence for synthesizing cyclopenta{[}b]indoles with great structural diversity in overall yields up to 37%. The key step was a palladium-catalyzed oxidative annulation of 3-alkylindoles (Fujiwara-Moritani reaction). The obtained cyclopenta{[}b]indoles were used as substrates in heterogeneous hydrogenation reactions to afford new fused indolines in moderate yields. An acid-catalyzed intramolecular cyclization of three such indolines gave tetracyclic lactams in 89, 90, and 61% yields. (AU)

• FAPESP's process: 13/10449-5 - Morita-Baylis-Hillman adducts as efficient building blocks for the synthesis of molecules of biological interest
• Grantee: Fernando Antonio Santos Coelho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07600-3 - CIBFar - Center for Innovation in Biodiversity and Drug Discovery
• Grantee: Glaucius Oliva
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC