Synthesis of aromatic dendrons with Pi-extended conjugation

ANA T. PIOTTO; ROLANDO A. SPANEVELLO; ALEJANDRA G. SUÁREZ; ANGEL RUMBERO SÁNCHEZ; JOSÉ G. LÓPEZ

Golden

Otro; Summer School on Sustainability and Green Chemistry; 2008

American Chemical Society

The synthesis of macromolecular systems constituted by aromatic rings or other functional groups with extended Pi conjugation and the study of the physical and chemical properties of these new materials is an area of great interest for its applications in nanoelectronics and nanophotonics. These applications are particularly important in artificial photosynthetic processes, photocatalysis, photovoltaic molecular cells, molecular informatics, optoelectronics and electrical, magnetical and non linear optical properties.Dendrimers are polymeric macromolecules composed of multiple perfectly branched monomers radially emanating from a central core. The synthesis of dendrimers with conjugated oligomeric chains has also generated high expectations due to the properties associated with this peculiar molecular structures. The 9-substituted polyfluorenes are building blocks that combine high electronic affinity with an extended Pi system that are of great value in the area of charge transfer complexes. For this reason, a fluorine derivative was chosen as starting material for the synthesis of the dendrons with a triethynylbencene scaffold as focal point.The present work describes the synthetic strategy used to obtaining two dendrons analogous (1a-b), using sequentially the reactions of Sonogashira and Wittig and the development of a new microwave assisted protocol for the preparation of 1,3,5-triethynylbencene.