Palladium-Catalyzed Double Reductive Cyclization of 2,3-Dinitro-1,4-dialkenylbenzenes. Synthesis of 1,8-Pyrrolo[3,2-]indoles.

Author(s) Ansari, N.H.; Banini, S.; Cummings, M.M.; Söderberg, B.C.G.
Journal J Org Chem
Date Published 2020 Mar 06

A flexible route to both symmetrical and unsymmetrical 1,8-pyrrolo[3,2-]indole has been developed. The key and ultimate step is a double palladium-catalyzed, carbon monoxide mediated reductive cyclization of 1,4-dialkenyl-2,3-dinitrobenzenes. The cyclization precursors were prepared by a double Kosugi-Migita-Stille cross coupling of 1,4-dibromo-2,3-dinitrobenzene with an alkenyltin reagent to give symmetrical products. Unsymetrical cyclization precursors were prepared by two sequential cross couplings using 4-iodo-2,3-dinitrophenyl trifluoromethanesulfonate as the starting material.

DOI 10.1021/acs.joc.9b03290
ISSN 1520-6904
Citation J Org Chem. 2020.