The Synthesis And Properties Of The New Axial N-P Ligands Induced By Central Chirality

In this dissertation, six new phenanthryl imidazoline ligands8a1-8e have been synthesized from9-bromophenanthrene. Phenanthryl imidazoline N,P-bidentate ligand9b, and N,S-bidentate ligand10b were prepared based on the ligand8b. The catalytic activity of10b was studied in the Friedel-Crafts alkylation reaction.1. Synthesis o f10-bromophenanthrene-9-carbaldehyde(5)10-Bromophenanthrene-9-carbaldehyde(5) was obatained by four steps starting from9-bromophenanthrene(1).2. Synthesis of phenanthryl imidazoline ligandsSix phenanthryl imidazoline ligands8a1-8e were synthesized by two different methods from10-bromophenanthrene-9-carbaldehyde.Method A:phenanthryl imidazoline ligand8a1was synthesized from10-bromophenanthrene-9-carbaldehyde(5) and (S,S)-diphenyl-ethylenediamine, then treated with4-toluene sulfonyl chloride to afford ligand8a2. The synthetic routes were as follows: Method B:imidazoline ligands8b-8e with phenanthrene backbone were synthesized by three steps reaction after the oxidation of compound5. It was found that a pair of diastereoisomer were obtained with chiral amino alcohols, de value is up to32%. However, using achiral ethanolamine could gain ligand8d, which was a pair of the racemic compounds. It was found that the axial chirality of phenanthryl imidazoline ligands was induced through the chiral amino alcohols. The new compounds8a1-8e were characterized by IR,1H NMR,13C NMR and MS.3. Synthesis of phenanthryl imidazoline N,P-bidentate ligandsPhenanthryl imidazoline N,P-bidentate ligand9b was achieved from PPh2C1and8b. The ligand10b was obtained by the vulcanization of the ligand9b.4. The application of10b in the Friedel-Crafts alkylationThe catalytic activities of ligand10b in the Friedel-Crafts alkylation of indoles with nitroalkenes was investigated. The reaction conditions of the solvent, temperature, reaction time and the metal salt were explored. Under the optimized conditions, the corresponding products could be obtained with up to92.6%yield.