Research On Selective Reaction Of Ti Enolates And Cross-coupling Reaction Based On Copper And Silver Carbene

Two aspects are discussed in this paper as following. First, the treatment of α-diazo-β-carbonyl phosphonates with Ti Cl4 gave the TiⅣenolates,and then addition reaction with unsaturated aldehydes or ketones take placed. A variety of1,2-addition productswere obtained prodominatly by selected Lewis acids-control.The reaction mechanism is proved by DFT calculation.Second, the synthesis of multi-arylsubstituted allenes,allenylphosphonates,E-eyeyne estersand 2,3,5-trisubstituted furan derivatives based on the copperand silver carbene migratory insertion reactionis discussed in this paper.Basic nature andnewsynthetic methodof diazo compouds are summarized in the first chapteras exordium. In the second chapter, the preparation of TIⅣenolates by treating α-diazo-β-carbonyl phosphonates with Ti Cl4 and then the reaction with unsaturated ketonesaredescribed.1, 2-Addition products were selectively obtianed in the presence of Lewis acids(Ti Cl4,Ti(i-Pr O)4, BF3·OEt2, Sn Cl4) or without any additives. The mechanismis proved by the DFT calculation.The reaction of the Ti enolates derived frombutyl ketone diazo phosphonates with alkynyl aldehydeswas investigated based on the previous work.1,2-Addition products were obtained not only regioselectivelybut also diastereoselectivity(approximately 100:0). In the thirst chapter, the migratory insertion based on copper carbene was explored. For example, the reaction of diaryldiazomethanes and diazophosphonates with terminal alkynes under the catalysis of copper(I) was studied, to synthesize mult-aryl substitued allene and alleneylphosphonates in a simple, efficient method.Amechanism based on copper carbene migratory insertion and protonation was proposed. In addition, the cross-coupling reaction of three components of isopropyl silicon acetylene, diazo acetic estersand aldehydes was investigated in the presence ofcopper(I),and a possible mechanism through copper carbene migratory insertion- nuclephlic addition- elimination pathway was suggested.Enynyl ethers, which are important intermediates,were synthesizedwith good selectivity of Z/E.The configuration wasconfirmed by NMR and X-ray diffraction. In the fourth chapter, our exploration focused on the silver-catalyzed synthesis of the 2,3,5-trisubstituted furan derivatives starting from conjugated enynones.