<i>In situ</i>vinylpyrrole synthesis. Diels-Alder reactions with maleimides to give tetrahydroindoles
作者:Wayland E. Noland、Nicholas P. Lanzatella、Elena P. Sizova、Lakshmanan Venkatraman、Oleg V. Afanasyev
DOI:10.1002/jhet.95
日期:2009.5
been prepared by a one-pot synthesis from 2-alkylpyrroles, cyclic ketones, maleimides, and an acid catalyst. A 5-vinylpyrrole is formed by an acid-catalyzed condensation of a 2-alkyl-substituted pyrrole with a ketone, which is subsequently trapped in situ by a maleimide in a predominantly endo-addition Diels-Alder reaction. Isomerization of the double bond into the pyrrole ring gives a tetrahydroindole