Study On Metal-catalyzed Ortho Group-induced Cycloaddition Of Regioselectivity Of Alkyne

Alkyne shows unique chemical properties in organic synthesis for its chemical structure of unsaturated carbon-carbon triple bond.Its functionalization reaction has become an important field of organic synthesis.In recent years,the ortho group-participated intramolecular cyclization of aromatic acetylene is favored by chemists and provides a simple,economical and effective way for the synthesis of many natural products,pharmaceutical molecules and fine chemical products.This thesis mainly focuses on the use of bifunctionalized alkyne substrates under mild conditions to synthesize heterocyclic skeletons with potential biological activity.1.Copper-Catalyzed 6-endo-dig O-Cyclization of 2-?But-3-en-1-yn-1-yl?benzamideA regioselective 6-endo-dig cyclization of aromatic acetylene by oxygen in o-site amides affected by alkynes catalyzed by copper salt was developed.Under the catalytic system of Cu?TFA?₂,three-vinyl isocentoumarin-1-imide compounds were synthesized using catalytic amount of Cu?TFA?₂-catalyzed intra-molecularly selective cyclization of o-enyl benzamide.The optimum conditions for this reaction:60?,Cu?TFA?₂?10%mol?,THF?2.0 mL?.The reaction has a high regioselectivity and a wide range of substrate applicability.The substrates of various substituents can obtain the expected product,the yield is higher.In addition,3-vinyl isocandin-1-imides can be used to synthesize 3-vinyl isocandin and 1-amino-3-vinyl isoquinoline compounds.2.Cerium-catalyzed 6-endo-dig cyclization of N-methoxybenzamideA regioselective 6-endo-dig cyclization of nitrogen-involving aromatic acetylene catalyzed by cerium salt was developed.The regioselective intramolecular cyclization of o-acetyl-N-methoxybenzamide using catalytic amount CAN?10%mol?under a CAN catalytic system to synthesize 3-hydroxy-isoquinoline-1,4-dione compounds.The optimum conditions for this reaction:80?,CAN%?10 mol%?,1,4-diaxone?2.0 mL?.The reaction has a high regioselectivity and a wide range of substrate applicability.The substrates of various substituents can obtain the expected product,the yield is higher.Furthermore,3-hydroxy-isoquinoline-1,4-dione compounds can be used to synthesize 3,4-dihydroxy-isoquinoline-1-one compounds.Mechanism studies show that the synthesis reaction of isocarabinoids is a Cu?TFA?_2-mediated intramolecular cyclization by oxygen attack,and the synthesis reaction of isoquinolinones is an intramolecular cyclization initiated by N-free radicals.