The Synthesis Of Novel Imidazoline Compounds And Their Application In The Asymmetric Suzuki-Miyaura Reaction

In this thesis, six imidazolines compounds with biphenyl backbone and twelve bi(imidazoline) ligands were synthesized and characterized. These chiral bis(im-idazoline) ligands were applied to asymmetric Suzuki-Miyaura reaction. The main research contents were as follows:1. Synthesis and structural characterization of imidazolines compou-nds with biphenyl backboneTwo chiral biphenyl imidazoline compounds4were synthesized from commercially available2,2’-biphenyldicarboxylic acid and amino alcohols in two steps. Then the compounds4were treated with NaOH and refluxed in mixed solvents of THF and MeOH. The compounds6and7were obtained in53-56%and53-56%yeild (Scheme1). All the new compounds4,6and7were characterized by IR, MS, HRMS,1H NMR and13C NMR and specific rotations. The molecular structures of4a,6b and7a were further confirmed by single-crystal X-ray analysis. 2. Synthesis and structural characterization of bi(imidazoline) ligandsThe chiral bi(imidazoline) Compounds8a-81were synthesized from commercially available dimethyl ester of oxalic acid and amino alcohols in five steps (Scheme2). All the new compounds8a-81were characterized by IR, MS, HRMS,1H NMR and13C NMR and specific rotations. The molecular structures of8a was further confirmed by single-crystal X-ray analysis.3. The application of chiral bi(imidazoline) ligands in asymmetric Suzuki-Miyaura reactionThe activity of chiral bi(imidazoline) Compounds8a-81in asymmetric Suzuki-Miyaura reaction of aryl iodines with aryl boronic acid was evaluated with various Pd, base and solvents at different reaction temperatures. The best results were obtain with Pd2(dba)3-8j as the catalyst using K3PO4·3H2O in1,4-dioxane at80℃(Scheme3).