Exploratory Research Of Novel Chiral Diphosphine Ligand And Syntheses Of Carbazole Ligands

This paper is composed of two parts: the exploratory research of novel diphosphine ligand and the syntheses of chiral biphosphine ligands.Asymmetric catalysis is one of the most actively pursued research areas in chemistry. The demand for new ligands with unique structural features and physical properties continues to grow in order to meet the requirements of a wide range of reactions and substrates. From both academic and practical standpoints, it is highly desirable to design and synthesize new chiral ligands and to test their application in the asymmetric catalytic reactions。Herein we attempted a synthetic route of novel diphosphine ligands through diphenyl with C2 axial in the 2,2'-position introducing 1H-1,3-benzazaphosphole。From o-Nitroaniline we prepared diethyl (2-aminophenyl)phosphonate. the intermediate compound 10 was synthesized from 3-methoxyacetophenone via nitration, diazotation/iodinaton, reduction, Ullmann coupling and oxidation. 2-aminophenyl phosphonate react with biphenyl chloride to form new compound diethyl (biphenyl) phenylphosphonate. The new compound has been characterized by 1H NMR and MS.In this paper, two novel carbazole ligands were designed. The intermediate compound 9H-(4'-iodobenzyl)-3,6-diiodocarbazole (19) was synthesized from carbazole. 19 reacted with CuCN to form 9H-(4'-cyanobenzyl)-3,6-dicyanocarbazole(20). dichlorobis -(triphenyl- phosphine)palladium(II) as the catalytic agent, 19 reacted with diethyl phosphite to form 9H-(4'-diethylphosphobenzyl)-3,6-bis(diethylphospho)carbazole(22). 9H-(4'-diphosphobenz -yl)-3,6-bis(diphospho)carbazole 23 was prepared by hydrolysising the compound 22. The new compounds 20, 22 and 23 have been characterized by 1H NMR, 13C NMR and 31P NMR.