Study On The Synthesis Of Acylazobenzene Derivatives Via Pd-catalyzed C-H Bond Activation

In this thesis, the synthesis of mono-and di-substituted acylazobenzenederivatives via Pd-catalyzed C-H bond activation was studied. The mainresultsobtained are as follows:Acylation of azobenzenes with toluene derivatives via palladiumcatalyzed C-Hbond activationAcylazobenzene and its derivatives are ubiquitous motifs and have been widelyapplied in the fields of functional advanced materials, chemical sensors,pharmaceuticals, food additives and industrial dyes. However, the process ofbuilding such a structure has lagged behind. Only several impressive examples haveemerged in recent two years. In the literature, aldehydes and É‘-oxocarboxylic acidswere used as acylation reagents. Recently, great attention has been paid to usetoluene and its derivatives as acylation reagents, due to its stability, low toxic andeasily availability compared to aldehydes and É‘-oxocarboxylic acids. An efficientprocedure to the direct mono-and di-substituted acylazobenzene derivatives hasbeen developed based on palladium catalyzed C-H bond activation (Scheme1). Thisnovel and practical method provides easy access to acylated azobenzenes usingcommercially available, low toxic, stable, and inexpensive toluene derivatives as thepotential and ideal acylation reagents and Pd(OAc)2(10mol%) as a catalyst. Variousmono-and di-substituted acylazobenzenes were obtained in up to91%and83%yields in regioselective and chemo-manners respectively. On the basis of controlledexperiments and the results found in the literature, a plausible reaction mechanismthat was proposed and is shown in Scheme2.