A. Golka, P. Keyte, M. Paddon-Row
Sep 4, 1992
Citations
0
Influential Citations
18
Citations
Journal
Tetrahedron
Abstract
Abstract The synthesis of some novel 1,4-dimethoxynaphthalene—bridge—heterocycle systems is described. In these systems, the naphthalene and heterocyclic groups are fused to a rigid bridge consisting of linearly fused norbornyl and bicyclo[2.2.0]hexyl groups. Bridges used herein have relays of 2, 4, and 6bonds long. The heterocycle is either 3.6-di(2′-di(2′-pyridyl)-pyridazino, or pyrido and was attached to the bridge by annulation methods. The pyridazino systems, 2 ( m,n ), were synthesized via Diels-Alder reaction of 3,6-di(2′-pyridyl)-1,2,4,5-tetrazine with the alkenes, 13 and 6 ( m,n ), and subsequent aromatization of the adducts with DDQ. Pyridine annulation was successfully carried out using two different methods: (i) Boger pyridine annulation of ketones, 11 , 20b , and 21b , (with 1,2,4-triazine and pyrrolidine); (ii) Diels-Alder reaction of alkenes 13 and 6 ( m,n ) with 3-thiomethyl-1,2,4-triazine, followed by Raney nickel reductive desulfurization of the aromatized adducts. The synthesis of Ru(II)(2,2′-bipyridyl) 2 complexes of the pyridazino systems. 9 ( m,n ) and 10 , is also described.