Design And Synthesis Of Chiral Oxamide Complex Catalysts And Their Application In Asymmetric Reactions

In the field of asymmetric catalysis,the development and application of new chiral ligands are crucial.Therefore,it is of significance to develop new chiral ligands with the features of easy synthesis,good chemical stability,as well as low cost.In the paper,the design,synthesis and application of chiral oxalamide ligands based on enantiomerically pure diamine compounds were explored,and the effect of carbonyl coordination of chiral oxalamide ligands was studied.The results showed that carbonyl coordination is significant for the stereocontrol of asymmetric reactions.The research contents of the dissertation were divided into the following three parts:In the first part,fourteen diamine-based chiral bis-oxalamides compounds were prepared in moderate to good yield(42-88%yields)via a one-pot two-step fashion.The chiral bis-oxalamides(CBOA),readily derived from optically pure 1,2diphenylethylenediamine(DPEN),were proven to be a class of efficient C2-symmetric chiral ligands for copper(Ⅱ)catalyzed asymmetric inverse-electron demand oxo-DielsAlder reactions between β,γ-unsaturated α-ketoesters and 2,3-dihydrofuran or 3,4dihydro-2H-pyran.The reactions proceeded smoothly under mild conditions and the corresponding[4+2]cycloadducts were obtained in high yields with excellent enantioselectivities(up to 94%ee)and diastereoselectivities(up to 99:1 dr).DFT calculations demonstrated that carbonyl coordination of chiral ligand to Cu(Ⅱ)was crucial for high stereo-induction.In addition,the chiral bis-oxalamide yttrium(Ⅲ)complex showed good stereocontrol ability in this transformation.These CBOA ligands exhibited high catalytic efficiency in the oxo-Diels-Alder reaction,and also showed some other salient features of structural fine-tunablity,chemical stability,and easy synthesis,which might reach to more practical applications in asymmetric catalytic reactions.In the second part,a class of chiral mono-oxamide-phosphine ligands based on diamine skeleton was designed and examined in the palladium-catalyzed asymmetric allylic amination of vinyl benzoxazinones with alkylamines.The corresponding reactions provided a series of enantiomerically enriched 2-allylanilines derivatives in high yields(up to 92%yield)with high enantioselectivities(up to 94%ee).The catalytic results showed that the oxamide moiety on the ligand can be employed as an effective coordinating site for the stereocontrol.In the third part,sixteen tetra-aryl substituted bis-oxalamide-Pd(Ⅱ)complexes were obtained in good overall yields(58-78%yields)with bis-oxalyl amide modified optically pure diphenylethylenediamine(DPEN)as a substrate.The reaction contained the Pd(Ⅱ)-catalyzed/oxalyl amide directed multi-step C(sp2)-H bond arylations and further intramolecular ligand exchange process.Meanwhile,these palladium complexes displayed highly efficient catalytic activity and broad substrate scope in Suzuki reaction.In addition,the resulted bis-oxalamide[N,O]chelated palladium complexes were endowed with robust steric and electronic adjustability,air-and moisture-stability as well as the single enantiomerical form,thus they might exhibit unique catalytic performance in other asymmetric catalytic reactions.