Palladium-catalyzed Dearomative Spirocyclization Of Alkynyl-based Biphenol

The spirocyclohexenone skeleton plays an important role in drugs,natural products and functional materials.Therefore,Enriching and developing the method for synthesizing the structures has great significance.The dearomative spirocyclization of the designed phenols and detrivatives has proven to be one of the most straightforward approaches to construct spirocyclohexenone framework.After the palladium-catalyzed cross-coupling reaction won the Nobel Prize in 2010,a large number of studies have been carried out,constructing the structure by using Pd(0)catalysis,and many effective methods for synthesizing spirocyclohexenone fragments have been discovered.This paper has summarized the palladium-catalyzed dearomative cyclizations of phenol-derived precursors,and a novel method for synthesizing spiro[4.5]cyclohexadienone compounds has been discovered.The first chapter,we summarize the palladium-catalyzed dearomative cyclization based on phenols.According to the difference of reaction,it has been divided into two categories,the first model is palladium-catalyzed intramolecular dearomatizing cyclization,the other is intermolecular.The second chapter,we designed a class of phenolic compounds containing three bonds,and found a new method for synthesizing spiro[4.5]cyclohexadienone compounds using those substrates.After optimizing the reaction conditions,we examined the substrate scope,and a plausible mechanism was proposed.The third chapter,we study another three-bonded compound.At last,we explore and discover a efficient method,which can transform propargyl alcohol to ?,?-unsaturated carbonyl compounds by metal-free catalysis.