A Domino Ring‐Closure Followed by Retro‐Diels–Alder Reaction for the Preparation of Pyrimido[2, 1‐a]isoindole Enantiomers. Issue 21 (24th June 2016)

• Record Type: Journal Article
• Authors: Fekete, Beáta; Palkó, Márta; Mándity, István; Haukka, Matti; Fülöp, Ferenc
• Is Part Of: European journal of organic chemistry. Issue 21(2016)
• Page Start: 3519
• Page End: 3527
• Publication Date: 2016-06-24
• Subjects: Synthetic methods -- Domino reactions -- Microwave chemistry -- Nitrogen heterocycles -- Chiral resolution; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201600434
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : A simple method was developed to prepare pyrimido[2, 1‐ a ]isoindole derivatives by using di‐ endo ‐ and di‐ exo ‐ethyl 3‐aminobicyclo[2.2.1]hept‐5‐ene‐2‐carboxylate enantiomers as chiral sources. The method is based on a domino ring‐closure reaction of norbornene 2‐aminohydroxamic acid followed by microwave‐induced retro‐Diels–Alder reaction. In the case of enantiomeric starting substances, the chirality is transferred from norbornene derivatives to pyrimido[2, 1‐ a ]isoindoles. The configurations of the synthesized compounds were determined by 1D and 2D NMR spectroscopy [based on 2D NOE cross‐peaks and 3 J H, H coupling constants] and X‐ray crystallography. Abstract : Racemic and enantiomeric pentacyclic isoindoloquinazoline derivatives were prepared by a domino ring‐closure reaction starting from β‐amino hydroxamic acids. A microwave‐induced retro‐Diels–Alder reaction of these derivatives yielded racemic and enantiopure dihydropyrimido[2, 1‐ a ]isoindoles