Synthesis Of Novel 1,3-butadienes By Sp~2 C-H Bond Activation

Butadiene is a widely presented functional skeleton and is usually found in many natural products,pharmaceutical and biologically active molecules.The new1,3-butadiene synthesis method based on sp~2C-H bond activation has been extensively studied.In this thesis,we describe:1)an oxidative coupling of Weinreb acrylamides and electron-deficient olefins to synthesize 1,3-butadiene with high region and stereoselectivity by rhodium catalyst;2)a ruthenium-catalyzed alkenylation of electron-deficient olefins with allyl acetate.This paper is divided into three chapters:In the first chapter,the coupling reaction based on sp~2C-H bond activation is introduced,and four kinds of reactions on coupling reaction between alkenes are described in detail:a).oxidative homo-coupling of olefins;b).oxidative cross-coupling of terminal olefins without directing group;c).oxidation cross-coupling of functional group-oriented olefins and terminal olefins;d).oxidation cross-coupling of cyclic olefins and terminal olefins.In the second chapter,a rhodium catalyzed reaction of Weinreb acrylamides and olefins to make 1,3-butadienes was disclosed.Herein,the amide group oriented oxidative coupling of electron-deficient olefins with Weinreb amidess was furnished to make butadiene compounds in high yields and excellent stereoselectivities,using rhodium catalyst.In the third chapter,a Ru-catalyzed coupling reaction of electron-deficient olefins with allyl acetates is investigated.Using amide as a directing group,the acrylamides reacted with allyl acetate efficiently to form valuable butadiene products with good stereo-and regioselectivities.This reaction was performed without any oxidant,employing inexpensive Ru complex as the catalyst.