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Intramolecular [4+2] cycloaddition of furfurylsubstituted homoallylamines to allylhalides, acryloyl chloride and maleic anhydride
Author(s) -
Varlamov Alexey V.,
Boltukhina Ekaterina V.,
Zubkov Fedor I.,
Nikitina Eugenia V.,
Turchin Konstantin F.
Publication year - 2006
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570430611
Subject(s) - chemistry , intramolecular force , acryloyl chloride , cycloaddition , acetic anhydride , maleic anhydride , aromatization , furan , substituent , ether , ring (chemistry) , medicinal chemistry , organic chemistry , stereochemistry , acrylate , catalysis , monomer , copolymer , polymer
Acylation of 4‐(furyl‐2)‐4‐ R ‐aminobut‐1‐enes and 4‐ R ‐4‐furfurylaminobut‐1‐enes with maleic anhydride, acryloyl chloride or allylhalides provided 3‐aza‐10‐oxatricyclo[5.2.1.0 1,5 ]decenes. The tricycles are formed via an initial amide formation followed by a stereoselective exo ‐IMDAF (Intramolecular Diels‐Alder of Furan). In case of competing cycloaddition (for compounds possessing two furan or two dienophilic moieties) the most substituted fivemembered cycle is preferably annulated. Refluxing of 4‐ R ‐4‐furfurylaminobut‐1‐enes in acetic anhydride led to exo ‐3‐aza‐11‐oxatricyclo[6.2.1.0 1,6 ]undecenes with the pseudoequatorial substituent R ‐4. Treatment of 3‐aza‐10‐oxatricyclo[5.2.1.0 1,5 ]decenes with PPA at 90−110°C promoted cyclic ether opening, aromatization and intramolecular cyclization reactions sequence to give the corresponding tetracyclic compounds — tetrahydroisoindolo[2,1‐ a ]quinolines and tetrahydroisoindolo[2,1‐ b ][2]benzazepines in good yields. Unusual products of ipso ‐substitution in aromatic ring were obtained on cyclization of N‐p‐R ‐substituted 2‐allyl‐4‐oxo‐3‐aza‐10‐oxatricyclo[5.2.1.0 1,5 ]dec‐8‐enes.