Palladium-Catalyzed Aminomethylamination Of Conjugated Enyne

Addition reaction of enyne is an important research direction in organic chemistry.Different functional groups can be introduced to the unsaturated carbon-carbon bond to directly and efficiently synthesize valuable molecules.The additive reaction of conjugated enyne has been a significant research field to which scientists pay much attention,which has two kind of addition forms,such as 1,2-addition and 1,4-addition.However,the selectivity of the reaction is difficult to control,it is a big challenge to obtain a certain additive product with high selectivity.Under the constant exploration of scientists,they have developed two methods for controlling the selective 1,4-addition of conjugated alkyne catalyzed by transition metals catalysts.One way is that we can introduce a steric bulky group on the triple bond terminal carbon of conjugated enyne,which can efficiently control the the site of insertion of the triple bond to obtain a 1,4-addition product.Another method is to introduce a carbonyl functional group at the middle carbon atom of the double bond to activate double bond,and the nucleophilic reagent selectively undergoes a nucleophilic addition reaction with the double bond to furnish a 1,4-addition reaction.These two strategies are very effective in the synthesis of 1,4-addition products of conjugated alkenes,but the limited scope of substrates hinders the widespread application of these two strategies.In combination with the palladium-catalyzed C-N bond activation strategy reported by our group,we envisaged that the highly electrophilic cationic palladium alkyl complex(Huang compex)formed by the oxidative addition of Pd(0)with an aminal can undergo the insertion reaction with a more active triple bond to yield ?-allyl palladium intermediate,thereby promoting 1,4-addition reaction of the conjugated enyne..In this thesis,we use simple conjugated enyne and aminals as substrate to optimize reaction conditions.we found that PdBr2 as a catalyst,AgOTf as a counter anion,large-angled bisphosphine ligand Xantphos as ligand,and DME as solvent,reacted at 80 ? for 12 hours after screening the palladium catalyst,ligands,solvent and temperature,the olefin 1,5-diamine compound can be obtained in a yield of 93%.The enyne have good functional groups compatibility,such as electron-withdrawing groups F,Cl,Br,NO2,electron-donating groups methyl,methoxy,etc.,heteroaryl ring-substituted conjugated enyne can be converted to the allene 1,5,diamines in 51%-93%yield,while the various substituted aminals can afford the product in 52%-91%yield.Moreover,the standard reaction was applied to the gram level,the target product was also obtained in a higher yield of 94%.The mechanism experiment confirmed that the reaction intermediate was ?-allyl palladium compound,and we speculated its reaction mechanism.The standard product is derivatized,and a dihydropyrrole derivative and a five-membered ring lactam compound are obtained by a method of debenzylation and reaction with carbon monoxide.