Studies On The Reactivity And Synthetic Applications Of 4-Trifluoromethyl-p-Quinols

Trifluoromethylated arenes are widely used in the fields of pharmaceuticals,agrochemicals,materials and aviation etc.However,naturally occurring trifluoromethyl arenes are rare and their synthesis often encountered the problems such as low selectivity and poor universality etc.Therefore,the development of synthetic methodology on trifluoromethylated arenes is highly attractive.This thesis focuses on developing new synthetic methods of trifluoromethylated arenes based on pre-functionalization strategy using the readily available 4-trifluoromethyl-p-quinols as non-aromatic precursors under mild reaction conditions in a single operation.The thesis is divided into five chapters.The first chapter mainly reviews the synthesis of trifluoromethylated arenes and synthetic applications of 4-trifluoromethyl-p-quinols.The thesis proposal is presented in chapter two.Chapter three describes a double nucleophilic addition/aromatization reaction based on4-trifluoromethyl-p-quinols.As dielectrophiles,4-trifluoromethyl-p-quinol silyl ethers react with two nucleophiles and generates trifluoromethylated arenes,regioselectively,via a novel meta-double functionalization.Chapter four describes the construction of p-(trifluoromethyl)benzyl compounds via in situ generation of p-(trifluoromethyl)benzyl electrophiles.Furthermore,N-methylsulfonamides,as products of the three-component reaction,can act as active,electrophilic(trifluoromethyl)benzylating reagents to react with a wider variety of nucleophiles to afford a diverse range of(trifluoromethyl)benzylated compounds.In chapter five,a novel Rh(III)-catalyzed synthesis of2-(trifluoromethyl)-dibenzopyranones from easily available 4-trifluoromethyl-p-quinols and N-methoxyarylamides is described.This protocol provides an efficient and regioselective route to 2-(trifluoromethyl)-dibenzo[b,d]pyran-6-ones via a formal anti-Michael addition/aromatization/lactonization tandem process.