Design And Synthesis Axially Chiral Phosphiamines Ligand By Using A Stereocontrol System

Homogeneous asymmetric catalytic hydrogenation is a kind of method which would obtaine chiral compound in high efficiency. The ligand with axially chiral is very important in this area. Herein, the design and synthesis of chiral ligand is an important subject in this research area.In this paper we design and synthesis an axially chiral phosphiamines ligand by using a stereo-control system.The detail is following: with 2,4-pentanedione as the starting material, with Ru-(S)-BINAP complexes as catalyst for homogeneous asymmetric catalytic hydrogenation, obtained of chiral compound (4-1) (2S, 4S) -2,4-pentanediol with two chiral centers. And then compound (4-1) and p-toluenesulfonic acid derivative reaction carried out to prepare chiral skeleton compound (4-2) (2S, 4S) -2,4 - pentanediol di-p-tosylate.With 2 - iodo -3 - nitro-phenol as the starting material, and reaction with mercury acetate obtained metal organic compounds (4-3) 2 - acetoxy-mercury -3 - nitro-phenol; again in potassium iodide solution, the presence of KI 3 ,the reaction carried out to obtaine (4-4) 2 - iodo -3 - nitro-phenol. Then reaction with the central chiral compounds (4-2) (2S, 4S) -2,4 - pentanediol di-p-tosylate obtained compound (4-5) (2R, 4R) -2,4 - bis [(2 - iodo -3 - nitro)-phenoxy]– pentane. In the copper-catalyzed intramolecular Ullmann coupling reaction, induced with axial chiral compound (4-6) (S) - (6,6 '- [(2R, 4R) -2,4– pentanedioloxy]) - (2,2 ') - dinitro - (1,1') - biphenyl; then reduced to amino-nitro-obtained compound (4-7) (S) - (6,6 '-- [(2R, 4R) -2,4– pentanedioloxy]) - (2,2 ') - diamino-- (1,1') - biphenyl. Then by (2-7), preparation of compound (4-8) (S) - (6,6 '- [(2R, 4R) -2,4– pentanedioloxy]) - (2, 2')– di-2-phenyl-phosphine amino - (1, 1 ') - biphenyl, as well as compound (4-9) (S) - (6,6' - [(2R, 4R) -2,4 - pentanedioloxy]) - (2,2 ') - diamino-- (3,5,3', 5 ') - -tetrakis-bromo - (1,1') - biphenyl.Characterized the major intermediates and target products in the synthesis route by 1HNMR and 13CNMR.