Construction Of Planar And Axially Chiral Molecules Via C-H Functionalization Strategy

The thesis mainly focuses on the construction of the planar and axially chiral molecules via C-H functionalization strategy,including asymmetric intramolecular C-H functionalization-cyclization of 3-aryl-1-(2-iodobenzyl)-1 H-indole,a BF3·OEt2-promoted cyclization of metallocenyl-enones to form cyclohexanone-fused metallocenes and a transition metal-catalyzed functionalization of 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione,followed by synthesis of new class of V-shape molecules with bi-phenanthridine skeletons.In the first part,by the modification of TADDOL-based phosphoramidite,we realized a palladium catalyzed asymmetric intramolecular C-H functionalization-cyclization of 3-aryl-1-(2-iodobenzyl)-1 H-indole.Indole-aryl axially chiral compounds were achieved with excellent yields(up to 99%)and good to excellent enantioselectivities(up to 91%ee).The reaction performed well with a series of substrates under mild conditions,New kinds of axially chiral skeletons was prepared by oxidation and hydrolysis of the products.In the second part,a BF3 OEt2-promoted cyclization of metallocenyl-enones to form cyclohexanone-fused metallocenes is reported.2,3-Metal locenocyclohexanones were formed exclusively and no normal Nazarov-type cyclopentanone analogue was detected.The reaction possibly proceeded via an unusual cationic 1,2-hydride shift followed by Friedel-Craft alkylative cyclization process.During the studies of alkylation reaction of these keto-esters an unusual and rare facial selectivity was observed.The electrophiles would be attacked from the same face as the second Cp ring.In the last part,an iridium and palladium mediated functionalization of 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione was reported.By the use of the corresponding imine,iridium or palladium complexes were prepared,and they were well characterized by NMR and single crystal X-ray crystallographic analysis.The catalytic activity of these metal complexes was briefly investigated in hydrogenation and 1,2-addition reactions.Finally,the catalytic bromination of 2,3:6,7-dibenzobicyclo[3.3.1]nona-2,6-diene-4,8-dione was realized in the presence of NBS and catalytic Pd(OAc)2.Subsequently a new class of V-shape molecules with bi-phenanthridine skeletons were synthesized.