The Synthesis Of Ar-BINMOLs-phos Chiral Ligands And Its Application In Asymmetric Synthesis

In asymmetric organometallic catalysis, chiral ligands generally play a critical role in numerous stereoselective transformations. Thus the design and synthesis of efficient chiral ligands is an area of challenging interest for developing efficient enantioselective metal-catalyzed reactions that provide facile access to optically pure compounds. Fellow this thesis, we have synthesized a series of multifunctional chiral phosphines with multistereogenic centres of axial and sp3-central chirality from a signal chiral source BINOL through a concise synthetic route, and studied the characteristic induction ability of these phosphine ligands in asymmetric organometallic catalysis reactions.Firstly, we have successfully developed an interested family of multifunctional chiral phosphines with multistereogenic centres of axial and sp3-central from a signal chiral source BINOL through a concise synthetic route, in which the enantioselective [1,2]-Wittig rearrangement mediated by neighbouring lithium is the key process in this diastereoselective synthesis of Ar-BINMOLs-Phos ligands. In the subsequent study, we evaluated these ligands in the catalytic alkynylation of aromatic aldehydes with terminal alkynes. The combination of these Ar-BINMOLs-Phos ligands with Zn Me2 afforded predominately the S-configured propargylic alcohols, whereas the additional use of Ca H2 and n-Bu Li along with the same Ar-BINMOLs-Phos ligands gave the R-configured products in high yields and excellent enantioselectivities(up to >99% ee). Thus it was demonstrated that the lithium-induced unexpected reversal of enantioselectivity takes place in this catalytic alkynylation.Recently, we have reported a new type of chiral phosphine ligand, for Copper catalytic asymmetric Huigen [3+2] cycloaddition of azides and alkynes. The desymmetrization of succinimide-derived bis(alkynes) was performed metrization of succinimide-derived bis(alkynes) was performed well in good yields with high enantioselectivities(up to>99% ee). The preliminary study suggested that the multifunctional chiral ligand play a crucial role in the formation of active binuclear or polynuclear catalyst in this asymmetric Cu AAC, in which both phosphine center and diol moiety were indispensable for the achievement of high yields and enantioselectivities.Therefore, present results further indicate the specific inducibility of Ar-BINMOL-Phos with multistereogenic centers in the asymmetric catalysis.