A New Type Of Chiral Sulfinamide-phosphine Ligands PC-phos:Synthesis And Application

Phosphine ligands,as the most widely used ligands,play an important role in the field of transition-metal-catalyzed reactions.During the past two decades,the use of chiral sulfur-phosphine as ligands in asymmetric transition metals catalysis has received much attention.Due to their diversity in the light of electronic properties and steric,and their advantages of special S-stereogenic control,stability and easy synthesis,chiral sulfur ligands are ideally suited as ligands for a widely catalytic applications.The ligands of bite angle has an apparent effect on the reactivity and selectivity in the transition-metal-catalyzed reactions.Therefore,it's still highly valuable to design and synthesize a novel chiral sulfur-phosphine ligands.The main work of this thesis focuses on the design and synthesis of the a new type of chiral sulfinamide-phosphine ligands(PC-Phos)based on xanthene skeleton,as well as their applications in asymmetric transition-metal-catalyzed reactions.The specific research contents include the following four aspects:(1)The design and synthesis of PC-PhosWe developed a new type of chiral sulfonamide-phosphine ligand based on xanthene skeleton,the two diastereomer of PC-Phos ligands,which could be easily made from inexpensive and readily available chiral tert-butyl sulfinamide one-pot strategy.The prominent features of PC-Phos,including their new skeleton,air stability,easy modification and synthesis,render PC-Phos very attractive.(2)Pd catalyzed enantioselective denitrogenative domino cyclization reactionswe have developed the first highly chemo-and enantioselective palladium-catalyzed denitrogenative cyclization reaction of benzotriazoles with allenes or N-allenamides with the use of chiral sulfinamides ligands PC-Phos.A series of optically active 2-substituted or 2,2-disubstituted 3-methyleneindolines bearing a quaternary stereocenter were obtained in high yields with excellent ees.This method can be expected to wide synthetic applications,in view of the high efficiency,operational simplicity,mild reaction conditions,free base,high chemo-and enantioselectivity.Besides,the products can be further functionalized to give a set of functionalized chiral indolines with high efficiency.We anticipate that inspired by this work,more catalytic asymmetric and synthetically usful transformations of benzotriazoles will be developed in near future.(3)Gold(I)/Xiang-Phos-Catalyzed Asymmetric Intramolecular Cyclopropanation of Indenes and Trisubstituted AlkenesWe demonstrated one intramolecular ACP of 1,6-enynes under the catalysis of Xiang-Phos/gold complexes.Chiral [5-3-6] fused-ring compounds with two vicinal all-carbon quaternary stereogenic center were prepared in high yields with excellent enantioselectivities under mild reaction conditions.This method provides an efficient,reliable and atom-economic strategy for the excellent diastereo-and enantioselectivity construction of highly valuable chiral [5-3-6] fused-ring compounds featuring two vicinal all-carbon quaternary stereogenic center.Moreover,the broad substrate scope,ease scale-up,the easily made ligand in large scale make this reaction quite practical and highly attractive.Further studies including synthetic application of this effcient transformation and the employment of the chiral catalyst to other reactions are currently in progress.(4)Synthesis of a Novel Series of Naphtho-Ferrocenes via a Gold(I)-Catalyzed Intramolecular CycloisomerizationA highly efficient and practical methodology has been applied to prepare variously substituted ferrocenyl naphthaquinone derivatives from 1-ferrocenyl-2-(non-terminal-ethynyl)benzene.The salient features of this reaction include a highly effective method for preparation of starting materials,mild conditions,easy to handle,quantitative yield and excellent functional-group tolerance.This work would shine some light on researching the luminescence and electrochemical properties of the PAHs-metallocene based two-dimensional core.