Study On Oxidative Coupling Reaction Of Nitrotoluenes

Quinazolines are an important class of nitrogen-containing heterocyclic compounds that possess a wide range of biological and pharmacological activities.The quinazoline skeleton is present in a variety of biologically active compounds and natural products.Besides,quinazolines could serve as valuable intermediates for various synthetic purposes including the preparation of functionalized materials.Based on previous studies,this thesis provides an method for synthesis of quinazolines by C-N oxidative coupling of nitrotoluenes.And the self-oxidative coupling reaction of nitrotoluenes was accidentally found in the course of research.Oxidative coupling reaction is a powerful chemical tool for constructing carbon-carbon and various carbon-heteroatom bonds.Its research results are widely used in various fields such as biology,medicine,pesticide,bionic,material and natural product synthesis,which greatly promoted the development of organic chemistry.Therefore,another purpose of this thesis is to develop a novel oxidative coupling strategy to achieve 2-(2-(quinolin-2-yl)vinyl)-quinolines,1,2-diarylethanones and 1,2-diarylethanols.The main contents of this thesis include the following three parts :1.Synthesis of quinazolines by C-N oxidative coupling of nitrotoluenes.The synthesis of quinazoline was carried out b y oxidation condensation of 2-nitrotoluene and benzylamine.Subsequently,reaction conditions for the synthesis of quinazolines were optimized and a series of quinazoline derivatives were obtained under the optimum conditions.This protocol possessed many advantages such as readily available,mild reaction condition and operational simplicity.2.C-C oxidative coupling reaction of nitrotoluenes.In the synthesis of quinazoline,it was found that the oxidative coupling reaction of nitrotoluenes can be carried out under the action of base and DMSO.The chemoselectivity can be easily switched by the selection of the base additives.1,2-Diarylethanones were obtained as the sole products in KOtBu/DMSO system at 30 °C.In contrast,1,2-diarylethanols were generated exclusively when the reaction was performed in K2CO3/DMSO system.This protocol provides a new pathway that avoids the use of transition metal catalysts for the synthesis of 1,2-diarylethanones and 1,2-diarylethanols.3.Derivation of C-C oxidative coupling reaction of nitrotoluenes.Inspired by the self-oxidative coupling reaction of 2-nitrotoluene,we have chosen to realize the self-oxidative coupling reaction of 2-methylquinoline whose electronic effect and structure are similar to 2-nitrotoluene.It has been proved that the theory is reasonable,and the coupling products of 2-methylquinolines have been successfully obtained.