Single and Consecutive Cyclization Reactions of Alkynyl Carbene Complexes and 8-Azaheptafulvenes: Direct Access to Polycyclic Pyrrole and Indole Derivatives

Autor:	Miguel Tomás, Angel L. Suarez‐Sobrino, Jaime Garcia‐Rodriguez, José Barluenga
Rok vydání:	2009
Předmět:	Indole test Chemistry Stereochemistry Transition metal carbene complex Organic Chemistry Regioselectivity General Chemistry Ring (chemistry) Catalysis Adduct chemistry.chemical_compound Reactivity (chemistry) Carbene Pyrrole
Zdroj:	Chemistry - A European Journal. 15:8800-8806
ISSN:	1521-3765 0947-6539
Popis:	The reactivity of alkynyl and enynyl Fischer carbene complexes towards 8-azaheptafulvenes is examined. Alkynyl carbenes 1 a-f undergo regioselective [8+2] heterocyclization with 8-aryl-8-azaheptafulvenes 2 a, b providing cycloheptapyrroles 3 and 4 with metal carbene or ester functionality at C3. Moreover, consecutive cyclization reactions are involved when enynyl carbenes are used. Thus, the cyclopenta[b]pyrrole framework 7 is formed by the consecutive [8+2] cyclization and cyclopentannulation reactions. The initially formed cyclopentannulation adduct can be intercepted through a Diels-Alder reaction with classic dienophiles to afford increasing structural complexity (compounds 8 and 9). More importantly, the construction of the indole skeleton is accomplished with a high degree of substitution and functionalization (compounds 11-15) by a one-pot sequence that involves [8+2] cyclization, R--NC or CO insertion, and ring closure.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ec8bc07106a5d2ac64003ad76e7c0204 https://doi.org/10.1002/chem.200901257 Zobrazit plný text záznamu Plný text