Application Of Indenyl Phosphine Ligand In C-N Coupling Reactions

The construction of C-N bond is important to organic synthesis chemistry.Aromatic amines,heteroaryl amines and their derivatives containing C-N bonds have important applications in many chemical-related fields,including agricultural chemicals,pharmaceuticals,electronic materials,organic dyes,et al.The transition metal-catalyzed C-N cross-coupling reaction is an important tool to form the C-N bonds.C-N cross-coupling reaction is widely used for synthesis of natural products,nitrogen-containing ligands,drug molecules and organic functional materials,due to its unique advantages including simple operation,mild reaction conditions,good substrate applicability and easy purification.But the application of aryl chlorides in C-N cross-coupling reactions are relatively less so far,in addition,the C-N coupling reaction at the solvent-free condition or in the aqueous phase are rare.In the transition metal-catalyzed C-N cross-coupling reaction,the ligand plays an very important role.The application of chiral P,N ligands in asymmetric catalysis is an integral part of organometallic chemistry and it is important in industrial applications and theoretical studies.Therefore,the syntheses of chiral P,N ligands have attracted much attention.It’s well-known that 2-bromo-indene is a cheap and readily available raw material,in which electron transfer can occur because of its conjugated character,and indene ring can form delocalized anion species,which further increases its coordination ability with metals associated with an increase of its electron density.Herein,an integrated catalytic system of a ligand L1 prepared by our laboratory and Pd(dba)2 was used to study its activity in the amination reactions occurred between(hetero)aryl chlorides and nitrogen-containing nucleophiles in the solvent-free condition or in the aqueous phase.The syntheses and structural characterizations of a novel P,N ligand 4 and six chiral P,N ligands(5,6,7,8,9,10)have been conducted.The related details of the presented work are described as follows:1.A catalytic system integrated a ligand L1 synthesized by our group with Pd(dba)2 was used to study its activity in the amination reactions occurred between(hetero)aryl chlorides and nitrogen-containing nucleophiles in the solvent-free condition or in the aqueous phase.2.A novel indenyl phosphine ligand(4)was designed and synthesized based on the cheap and readily available 2-bromoindene.And six chiral P,N ligands(5,6,7,8,9,10)were designed and prepared from the R(+)-α-methylbenzylamine.The structures of the above compounds were characterized by 1H NMR,13C NMR,31P NMR and high resolution mass spectrometry.The structures of borane protected ligands 4b and chiral P,N ligand 8 were confirmed by X-ray diffraction techniques.