The Synthesis Of Chiral Bis(Imidazoline) Ligands And Their Application In The Asymmetric Friedel-Crafts Reactions

In this thesis, seven glutaronitrile derived and two benzylidene bis(imidazoline) ligands were synthesized and characterized. These bis(imidazoline) ligands were applied to asymmetric Friedel-Crafts reaction. The main results were shown as follows:1. Synthesis and characterization of glutaronitrile derived bis(imidazoline) ligandsCompound3was prepared from glutaronitrile1in two steps, and then condensation with benzene sulfonic chloride and substituted benzene sulfonic chloride furnished corresponding glutaronitrile derived bis(imidazoline) ligands3a-h(Scheme1). All of3b-h are new compounds and characterized by*H NMR,13C NMR, IR, MS and HRMS.3c and3h were confirmed by single-crystal X-ray analysis.2. Synthesis and characterization of benzylidene bis(imidazoline) ligands. Compound6was prepared from dicarboxylic acid4in two steps, as illustrated in Scheme2. The dicarboxylic acid4was treated with oxalyl chloride in CH2CI2to yield the diacyl chloride and directed react with1.8equiv. of amino alcohol to obtain the corresponding chiral amido alcohols5. The catalytic amount of DMF was critical for the conversion. SOCl2was added to amido alcohols5and refluxed for10h, then SOCl2was removed under reduced pressure, which was directly treated with amine and stirred for24h, then10%NaOH was added to afford the ligand6. All of6a-b are new compounds and characterized by1H NMR,13C NMR, IR, MS and HRMS.3. The application of glutaronitrile derived bis(imidazoline) complexes in the asymmetric Friedel-Crafts reactionThe reaction of indole with nitrostyrene was under researched (Scheme3). The optimal reaction conditions are as follows:under Ar atmosphere,12mol%3e and10mol%Zn(OTf)2as the catalyst, indole and nitrostyrene5:1reacted in toluene with10mol%Et3N at10℃for48h, getting80%yield and42%enantioselectivity. The scope of the reaction of indole with nitroalkenes was explored, getting a moderate yield and enantioselectivity. 4. The application of benzylidene bis(imidazoline) complexes in the asymmetric Friedel-Crafts reactionThe reaction of indole with nitrostyrenes was under researched (Scheme4).12mol%6a and10mol%Cu(OTf)2as the catalyst, indole and nitrostyrene1:2reacted in toluene at0℃for24h under Ar atmosphere, getting the product with a moderate yield and enantioselectivity.The reaction of indole with benzylidene malonate was olso under researched (Scheme5).12mol%ligand and10mol%Cu(OTf)2as the catalyst, reacted in isobutanol at r.t. for60h under Ar atmosphere, getting the product with a general yield and enantioselectivity.(Scheme5)...