The synthesis of a verdazyl radical-derived biphenylophane
摘要:
Biphenylophanes with two stacked biphenyl units are synthetically challenging and consequently are rare. Herein, we report on the synthesis of a [3.3](3,4',3,4')biphenylophane, formed from bifunctional verdazyl radicals. Its formation is surmised to originate from two intermediate verdazyl radical-derived azomethine imines and their subsequent tandem inter-intramolecular 1,3-dipolar cycloaddition reaction with each other. Crown Copyright (C) 2012 Published by Elsevier Ltd. All rights reserved.