Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling Reaction And Intramolecular Heck Reaction

The contents of this thesis include(â…°) the Pd(OAc)₂/β-Oxo amides catalyze Suzuki-Miyaura cross-coupling reaction,(â…±) ipso-cyclizations of 1-(2-iodobenzyl)-1-azaspiro[4.5]-triene-8-ones,and(â…²) the Heck reactions of 1-(2-iodobenzyl)-1-azaspiro[4.5]-triene-8-ones.The Suzuki-Miyaura reaction,ipso-cyclization reaction and Heck reaction are the important methods for the construction of new C-C bonds in organic synthesis.1.Progress in the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction and Heck reaction are summarized.We discussed the effects of ligands,catalysts,and additives on the Suzuki-Miyaura cross-coupling reaction and Heck reaction detailedly.The mechanisms are also reviewed.2.The Suzuki-Miyaura cross-coupling reaction of aryl halides and arylboronic acids has been developed using Pd(OAc)₂/β-Oxo amides as the catalytic system.In the presence of Pd(OAc)₂ and N-(4-methoxyphenyl)-3-oxobutanamide,a variety of aryl halides were coupled with arylboronic acids successfully in moderate to excellent yields provding high turnover numbers(maximum TONs=950 000 and TOFs= 79 167).The results showed that N-(4-methoxyphenyl)-3-oxobutanamide was an inexpensive and efficient ligand. 3.ipso-Cyclization of N-arylpropiolamides was studied in the presence of NBS.We found that N-(2-iodobenzyl)-N-aryl-3-phenyl propiolamides could undergo the intramolecular electrophilic ipsocyclization with NBS to synthesize the corresponding spiro[4,5]trine-8-ones in good yields.4.Two catalytic systems for the Heck reactions of 1-(2-iodobenzyl) -1-azaspiro[4.5]-triene-8-ones have been developed:(1) Pd(OAc)₂ combined with PPh₃ and NaHCO₃ was found to be an efficient catalytic system for the Heck reactions of 1-(2-iodobenzyl)-1-azaspiro[4.5]-triene-8-ones at 120℃under the argon atmosphere.1-(2-Iodobenzyl)-1-azaspiro[4,5]-triene-8-ones underwent the intramoleecular Heck reaction with this catalytic system smoothly to construct a new six-membered ring. (2) Another efficient catalytic system has also been developed,in the presence of PdCl₂(PPh3)2/TBAB/Et₃N,the Heck reactions of 1-(2-iodobenzyl)-1-azaspiro[4.5]-triene-8-ones were conducted successfully at 120℃under the atmosphere of argon,followed by protonation to afford the crossponding six-membered-ring products.