Incorporation of a Molecular Hinge into Molecular Tweezers by Using Tandem Cycloadditions onto 5,6-Dimethylenenorbornene
摘要:
Site-selective 1.3-dipolar coupling at the norbornene pi -bond of 5,6-dimethylenenorbornene I yields cycloadducts with an end-fused 1.3-diene system which have been reacted with N=N (or C=C) dienophiles to produce ribbon molecules. in which the internal diazacyclohexene (or cyclohexene) subunits are capable of acting as conformational hinges. Direct coupling of 5,6-dimethylene- norbornene with 1.3,4-oxadiazoles or dual coupling with bis(cyclobutene epoxides) afforded bis(1,3-dienes) that diastereoselectively react with dienophiles to produce new. conformationally mobile. molecular tweezers.
A new building block technique based on cycloaddition chemistry for the regiospecific linking of alicyclic sub-units as a route to large, custom-functionalised structures
作者:Ronald N. Warrener、Austin C. Schultz、Douglas N. Butler、Shudong Wang、Indu B. Mahadevan、Richard A. Russell
DOI:10.1039/a700010c
日期:——
A new building BLOCK approach to synthesis has been developed where
functionalised norbornenes (BLOCK A) are coupled with functionalised
cyclobutene epoxides (BLOCK B) to produce A + B structures of defined
geometry; use of a dual (spacer) BLOCK allows the formation of large
structures where crown ether, ligand and redox centres are incorporated in
similar or mixed pairings.