Synfacts 2008(3): 0239-0239  
DOI: 10.1055/s-2008-1042745
Synthesis of Heterocycles
© Georg Thieme Verlag Stuttgart · New York

Ring Expansion of Tetrahydroisoquinolines to Form Benzoazocines

Contributor(s): Victor Snieckus, Johnathan Board
L. G. Voskressensky*, A. V. Listratova, T. N. Borisova, G. G. Alexandrov, A. V. Varlamov
Peoples’ Friendship University of Russia, Moscow, Russia
Further Information

Publication History

Publication Date:
21 February 2008 (online)


Reported is a synthesis of azocines from tetrahydroisoquinolines by ring expansion using an activated alkyne. A mechanism is proposed which involves initial formation of a zwitter­ion species (structure A above) by Michael addition of the tertiary amine to an alkyne, followed by a mechanistically unknown rearrangement to afford the azocine.