Palladium-catalyzed Buchwald-Hartwig Coupling To Construct Axially Chiral Azabiaryl Compound

Azo-chiral compounds exist widely in many important natural products and drug-active molecules,and are the core skeleton of many ligands and catalysts.Asymmetric coupling reaction,as one of the strategies for the efficient construction of chiral compounds in azotaxis,is very important for the research in this field.Considering the potential applications of azo-chiral compounds in natural products and drug design,Buchwald-Hartwig reaction has become a powerful tool for constructing C-N bonds in the past decades.We construct azo-aryl-chiral compounds by Buchwald-Hartwig reaction,as described below:Part Ⅰ: Palladium-catalyzed Buchwald-Hartwig reaction to construct C-N biaryl axis chiral compoundsAmidine compounds,as a class of isomers that are easy to coordinate with palladium catalysts leading to catalyst inactivation,and aramidine numerous isomers have always been a problem in asymmetric catalysis.The efficient asymmetric synthesis of C-N biaryl chiral compounds has been achieved by means of Buchwald-Hartwig amination strategy catalyzed by palladium.A series of C-N axis chiral compounds have been synthesized using the cheap and readily available(S)-BINAP as ligand.Part Ⅱ: Palladium-catalyzed Buchwald-Hartwig reaction to construct N-N biaryl axis chiral compoundsN-N biaryl chiral compounds were constructed by palladium-catalyzed de novo construction of indole rings.The reaction has the characteristics of high yield,good enantioselectivity control and wide application range.In the conversion application,N-N biaryl-axis chiral monophosphine ligand was synthesized,which provided a new idea for the development of N-N axis chiral ligand.In conclusion,we successfully achieved asymmetric synthesis of C-N/N-N biaryl chiral compounds by Buchwald-Hartwig amination reaction.A series of chiral nitrogen compounds were synthesized with excellent yield and high enantioselectivity.