AbstractsChemistry

The Rh2-Catalyzed Formation of 1,2,3-Trisubstituted Indoles and Synthesis of Organic Electronic Materials

by Crystalann Jones




Institution: University of Illinois – Chicago
Department:
Year: 2015
Keywords: Substituted Indoles; Azides; Organic Semiconducting Materials; Pyrrolothiophenes; Organic Field effect Transistors; Cruciforms; benzobisoxazole; Fluorophores, ion sensors
Record ID: 2058854
Full text PDF: http://hdl.handle.net/10027/19366


Abstract

The construction of 6- or 4-(poly)substituted indoles as single isomers has remained a synthetic challenge due to the poor selectivity of Fischer indole-type processes. In a methodology study rhodium(II) carboxylate complexes have been discovered to access the formation of polysubstituted indoles inaccessible via the Fischer-indole reaction. 1,2,3-trisubstituted indoles are formed from α,β,β-trisubstituted styryl azides through selective β-carbonyl migration. The reaction tolerates a wide range of functional groups at the α-position as well as on the aryl azide and the styryl azide precursors are readily available in two steps. Interest in organic semiconducting materials as low cost alternatives to inorganic materials for the purposes of energy conversion and storage has rapidly increased due to their ease of synthesis and potential processibility in printable electronics. Therefore a series of highly soluble bispyrrolothiophenes were prepared as building blocks for the synthesis of an organic semiconducting oligomer. Modifications on the end-pyrrolothiophene moieties, as well as the central arene linker were examined. The solution-state optical and electrical properties of the materials were investigated. Thin film devices were constructed from these bispyrrolothiophenes and evaluated as potential field effect transistors. The best device performance was displayed by a bispyrrolothiophene linked with benzothiodiazole exhibiting a mobility of 0.136 cm2/(V s) and an Ion/Ioff of 106 and VT of –37 V. Found to have applications in areas such as organic field effect transistors, nonlinear optical materials and sensors, cruciforms are gaining the attention of investigators across multiple fields. These X-shaped compounds can be manipulated structurally to induce spatial separation of the molecular HOMO and LUMO onto perpendicular axes. A new class of bispyrrolothiophene benzobisoxazole cruciforms has synthesized displaying promising optical and electronic properties. When the electron-deficient axis contains pyridines, zinc 2+ ions are readily complexed making them excellent sensors