Study On The Cycloaddition Reaction And Derivatization Of 1,3,3-Triarylpropyne

1,3,3-triarylpropynes are readily accessible compound with unique reactivity.The deprotonation of 1,3,3-triarylpropynes on sp3 carbon with the promotion of base can tautomerize to allene intermediates with higher intermediates and enables more diverse reaction.Moreover,1,3,3-triarylpropyne can act as suitable partner to undergo annulations catalyzed by transition metals.Iron is an ideal transition metal.It is abundant in nature,low in price,non-toxic and environmentally friendly.It usually has obvious advantages in sustainable chemistry,so it is an attractive alternative to other commonly used transition metals.In recent years,the use of easy-to-handle and usually air-stable iron salts for such purposes has greatly increased,and now a large number of iron-catalyzed/mediated methods are available,offering new possibilities for organic synthesis.This dissertation is divided into two parts:(1)the base-mediated deprotonation/isomeration of 1,3,3-triaryl alkynes into allene intermediates,and their[2+2]dimerizations;(2)ruthenium-catalyzed annulations of N-methoxybenzamide with 1,3,3-triaryl alkynes to afford quinolones,and their further derivatizations promoted by FeCl3.In the first part,we developed LDA-promoted regioselective[2+2]dimerization of allenes from the deprotonation/isomeration of 1,3,3-substituted propynes,subsequently quenched by electrophiles to afford a variety of highly functionalized alkylidenecyclobutenes under extremely mild condition.This reaction displayed an unusual ortho-regioselectivity that was different from tail to head[2+2]cycloaddtion of allenes previously reported.In addition,the photophysical properties of some fluorescent products were also studied.In the second part,we developed the FeCl3-promoted tandem carbon-carbon cleavage/cyclization of quinolones to give phenanthridones,which are useful fluorophores.The electron effect on their photophysical properties is further evaluatedd.