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Easy access to medium rings by entropy/strain reduction, Part 3 . Competition between dihydroazepine and enamine formation in reaction of tetrahalosubstituted dibromides with primary amines
Author(s) -
Walsh James G.,
Gilheany Declan G.
Publication year - 2002
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.5570390624
Subject(s) - chemistry , enamine , potassium carbonate , medicinal chemistry , toluene , benzazepine , stereochemistry , primary (astronomy) , organic chemistry , catalysis , physics , astronomy
The reaction of Z,Z‐2,3,4,5‐tetrahalo‐2,4‐dien‐1,6‐dibromides ( 3 , R 1 ‐ R 4 = Cl, Br) with primary amines in the presence of potassium carbonate leads to both the dihydroazepines 4 and secondary enamines 5 . The formation of enamine is suppressed with toluene sulfonamide as nitrogen source. (2Z,4Z)‐2,3,4,5‐Tetrabromo‐hexa‐2,4‐diene‐1,6‐diol (2, R 1 ‐ R 4 = Br) is atropisomeric in solution.