Ring-closing metathesis approach to symmetrical and unsymmetrical cycloakeno[c]fused 2,2′-bipyridine-based cyclophanes
摘要:
Ring-closing metathesis reactions of symmetrical and unsymmetrical cycloalkeno[c]fused 2,2'-bipyridines, substituted at the alpha and alpha' positions of the pyridine rings with sufficiently long alkenyl ethers, afforded 16-membered cyclophanes, possessing variously annulated 2,2'-bipyridine subunits. (c) 2005 Elsevier Ltd. All rights reserved.
A simple and efficient synthesis of annulated 2,2′-bipyridinium salts with attached dihydrothiazole or dihydro-1,3-thiazine rings has been developed through tandem S-transalkylation/intramolecular ring closure of 2,2′-bipyridine alkyl sulfides. The structures were confirmed by X-ray crystallographic analysis.