Applications Of Hydroxylamine Derivatives Toward Nitrogen-Containing Compounds

Hydroxylamines working as readily available starting materials have great potential application in organic synthesis and the related fields.During the past serval decades,the synthetic application of hydroxylamine derivatives is always one of hottest topics in synthetic organic chemistry.This thesis expatiates the properties of hydroxylamines,classifies and lists the recent reports about the application of hydroxylamine derivatives in synthetic organic chemistry.This thesis presents the research progress about the use of hydroxylamine derivatives in carbon-nitrogen or carbon-oxygen bond construction.On the basis of our previous work,we designed and synthesized a series of novel hydroxylamine derivatives,which were used to construct aza-heterocyclic,nitrile,?-amino alcohols and vicinal diamines under photocatalysis or mild reaction conditions.This thesis can be divided into three major parts:First,we have developed a one-pot synthesis of phenanthridines and quinolines from commercially available or easily prepared aldehydes.O-(4-cyanobenzoyl)hydroxylamine is utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes catalyzed by Br(?)nsted acid.O-acyl oximes are then subjected to visible light photoredox catalyzed cyclization via iminyl radicals to furnish aza-arenes.A variety of phenanthridines and quinolines have been prepared assisted by Br(?)nsted acid and photocatalyst under visible light at room temperature with satisfactory yields.Second,we have presented a direct synthesis of nitriles from commercially available or easily prepared aldehydes.O-(4-CF3-benzoyl)-hydroxylamine(CF3-BHA)is utilized as the nitrogen source to generate O-acyl oximes in situ with aldehydes,which can be converted to nitriles with the assistance of a Br(?)nsted acid.Various functionalized aliphatic,aromatic and ?,?-unsaturated nitriles were prepared in high yields.The late-stage modification of spiramycin to the corresponding nitrile in a gram scale is also achieved in a satisfactory yield.The advantages,such as simple and mild conditions,high yields and good functional group tolerance,may lead to application of this method for the synthesis of nitriles.Third,nitrogen-triggered radical relay reactions have been achieved.1)A concept novel strategy to synthesize ?-alkoxy(amino)-y-aminoketones is presented.This strategy is enabled by photoredox-catalyzed multi-component radical reactions of styrenes,enol(enamine)derivatives and O-acyl hydroxylamines in DMSO.Four bonds(one C-C,one C-N and two C-O)are formed in a single operation.The broad synthetic application of this method has been demonstrated by the reaction of the structurally diverse reaction components including complex molecular scaffolds.2)A novel radical relay strategy for the synthesis of functionalized ?-aminomethyl cinnamyl alcohols has been developed.This strategy is enabled by photoredox-catalyzed and N-radical-triggered cascade reactions of phenylacetylenes,enol derivatives and O-acyl hydroxylamines in DMSO.1,5-hydrogen atom transfer(HAT)give a-oxy benzyl radical which undergo the subsequent oxidation and hydrolysis afford the final de-O-benzyl product.The broad synthetic application of this method is demonstrated by the reaction of structurally diverse reaction components,including complex molecular scaffolds.