Synthesis 2013; 45(24): 3413-3425
DOI: 10.1055/s-0033-1340305
paper
© Georg Thieme Verlag Stuttgart · New York

The Synthesis of Rigid Chromophore–Spacer–Chromophore Dyads and Three-Armed Triads by the 1,3-Dipolar Reaction of Cyclobutene Epoxides with Aromatic Dipolarophiles

Davor Margetić*
a   Laboratory for Physical Organic Chemistry, Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia   Fax: +385(1)4561008   Email: margetid@irb.hr
,
Douglas N. Butler
b   Intelligent Polymer Research Institute, Molecular Architecture Unit, University of Wollongong, Wollongong, NSW 2500, Australia
,
Ronald N. Warrener
b   Intelligent Polymer Research Institute, Molecular Architecture Unit, University of Wollongong, Wollongong, NSW 2500, Australia
› Author Affiliations
Further Information

Publication History

Received: 30 July 2013

Accepted after revision: 23 September 2013

Publication Date:
04 November 2013 (online)


Abstract

A series of polyaromatic hydrocarbons (PAHs) or their aza derivatives were reacted as dipolarophiles with ring-fused cyclobutene epoxides (CEs) in the 1,3-dipolar cycloaddition protocol to form 1:1 cycloadducts. The dihydroforms of the PAH chromophores contained in the rigid alicyclic scaffold were dehydrogenated to regenerate the original PAH chromophore and constituted a new route to rigid chromophore-nσ-PAH dyads separated by an alicyclic scaffold. The anthracene 1:1 adduct derived from the reaction with the 5,8-dimethoxynaphthalene-containing CE was reacted a second time to produce stereoisomeric three-armed triads in which naphthalene chromophores were attached rigidly onto scaffold. Two approaches were used to generate the incipient cyclic 1,3-dipolar intermediates involved in cycloaddition process. The first method employed ring-opening of functionalised CEs, the other method produced the dipolar reagent in situ by loss of dinitrogen from the initially formed adduct resulting from treatment of fused norbornenes with 2,5-bis(trifluoromethyl)-1,3,4-oxadiazole.

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