Premium
Synthesis of Phenanthridine Derivatives Functionalized in the C‐Ring by Means of IMDAF Reactions under Microwave or Conventional Heating Conditions
Author(s) -
Gulbrandsen Håkon Sætren,
Hennum Martin,
Osheka Maksim,
Read Matthew Lovell,
Gundersen LiseLotte
Publication year - 2014
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201403111
Subject(s) - phenanthridine , chemistry , aromatization , ring (chemistry) , intramolecular force , adduct , electrophilic aromatic substitution , microwave heating , photochemistry , diels–alder reaction , microwave , medicinal chemistry , organic chemistry , catalysis , physics , quantum mechanics
Phenanthridines functionalized in the C‐ring have been synthesized by IMDAF (intramolecular Diels–Alder reaction on furans) cyclization of ortho ‐furyl(alkenylamino)arenes under both microwave and conventional heating conditions. The outcomes of the reactions are highly dependent on the substitution patterns both on the dienophile and on the arene components. 5,6‐Dihydrophenanthridines, which can easily be oxidized to fully aromatic phenanthridines, are formed under microwave conditions as long as the Diels–Alder adduct contains a hydrogen atom in the 6a‐position. Aromatization of the phenanthridine C‐ring does not occur when the cyclization is performed under conventional heating conditions. The IMDAF reaction can, under these conditions, lead to Diels–Alder adducts or to phenanthridines with partially saturated and functionalized C‐rings, depending on the detailed structure of the starting material.