The chemistry of 2 pyranones and their Application in the development of small Fluorescent molecules

Abstract

Pyranones and its analogs are prominent scaffolds in synthetic and natural newlineproduct chemistry. The base promoted ring transformations of 2H-pyran-2-ones newlinewith various nucleophiles has become a well-known topic in synthetic, medicinal newlineand material chemistry. 2-Pyranones are versatile synthons for the construction newlineof polyarylbenzenes, functionally crowded benzenes and heterocyclic compounds newlinethrough ring transformation strategy. Additionally, pyranones incorporated with newlinedonor and acceptor push-pull system have been extensively used for the development newlineof fluorescent-based molecules with interesting photophysical and electrochemical newlineproperties. During our ongoing study on ring transformation of 2H-pyran-2-ones, we newlinehave developed an expedient method for the synthesis of functionalized 2-tetralones newlinethrough the ring transformation of 6-aryl-2-oxo-4-amino-2H-pyran-3-carbonitriles newlinewith 1,4-cyclohexanedione monoethylene ketal to give spirocyclic ketals followed by newlineacidic hydrolysis. This method is associated with notable advantages such as free from newlineany organometallic reagents/metal catalyst, broad substrates scope, shorter reaction newlinetime and tolerated wide range of functional groups which could be explored for further newlinesynthetic modifications. Also, we designed a novel colorimetric and fluorometric 2- newlinetetralone-based chemosensor for the selective detection of Cu2+ ion in semi-aqueous newlinesolution and were characterized by various analytical techniques. newlineFurther, a metal-free synthesis of 1,2-diarylbenzenes was achieved by treating 6- newlinearyl-2H-pyran-2-ones with arylacetaldehydes as carbon nucleophile using KOH/DMF newlinereagent system in good yields. Also, synthesis of 1,3-diarylbenzenes and 1,2,3- newlinetriarylbenzenes were synthesized using propiophenone derivatives and benzyl aryl newlineketones as carbanion sources respectively. The synthesized compounds exhibited newlineinteresting photophysical properties. On the other hand, we have reported efficient newlinesynthesis of allylbenzene derivatives via KOH-mediated ring transformation of highly newlinesubstituted 2H-py