Synthesis And Photophysical Properties of Functionalized Arenes and Heteroarenes

Abstract

2H-Pyran-2-ones are one of the fascinating unsaturated heterocyclic systems and newlinefound extensively valuable in pharmacological properties. Apart from biological newlineprofile, functionalized 2H-pyran-2-ones have been extensively explored as versatile newlinesynthons for various arenes, heteroarenes and fused systems. 2H-Pyran-2-ones are newlinehighly exploited for the synthesis of biologically relevant molecules such as biaryl, newlineteraryl benzenes, 2-aminopyridines, 2-pyridinones, _-methylstyrenes and 2-aminoisophthalonitriles newlinethrough ring transformation methodologies. Additionally, variation in newlinetheir molecular structures i.e. donor and acceptor pyranones have been widely used in newlinemany applications by virtue of their interesting photophysical and electrochemical properties. newlineThe base promoted ring transformations of 2H-pyran-2-ones with various nucleophiles newlinehas become a well-known topic in different field such as synthetic, medicinal newlineand material chemistry. During my ongoing study on ring transformation of 2H-pyran- newline2-ones, I have synthesized numerous functionalized aromatic systems. The synthesis of newlinebiaryl and teraryl-cored diarylmethanes was achieved by a metal-free convergent route newlinevia ring transformation of 2H-pyran-2-ones with a suitable nucleophiles in presence of newlineKOH in DMF at room temperature. Similarly, fused heterocycles like tetrahydroisoquinolines, newlinetetrahydronaphthoisoquinolines and hexahydronaphthoisoquinolines were newlineobtained in good to excellent yields by the transformation of polysubstituted and fused newline2H-pyran-2-ones consuming tert-butyl-4-oxopiperidine-1-carboxylate as nucleophilic newlinesource followed by acid-mediated cleavage of tert-butyloxycarbonyl group using trifluoroacetic newlineacid. Various functional groups were tolerated successfully under mild newlinereaction conditions. Next ring transformation strategy was employed for the synthesis newlineof m-terphenyls using naphthyl and biphenyl ketone as a source of carbanion at room newlinetemperature. Further, the functionalized stilbenes were efficiently synthesized in good newlineyields using various nucle