The Application Of Chiral Phosphine Ligands Sadphos In Asymmetric Metal Catalysis

Asymmetric metal catalysis has become a hot research field of chemists,because of it is an efficient synthetic method to construct chiral compounds,in which chiral ligand is the key point of stereoselectivity control.Based on the chiral tert-butanesulfinamide,we have prepared a novel type of chiral phosphine ligand Sadphos(Sulfinamide phosphine),which has excellent performance in asymmetric organic catalysis and asymmetric transition-metal catalysis.In view of our “Sadphos” and our previous work,this paper is aimed to extend the utilization of Sadphos.The main work is as the following three parts:1.Axially chiral biaryl monophosphine oxides enabled by palladium/WJ-Phos-catalyzed asymmetric Suzuki-miyaura cross-couplingThe palladium-catalyzed asymmetric Suzuki-Miyaura coupling reaction is one of the most commonly methods for the construction of axially chiral biaryl monophosphonates.However,the classical limitations have included the low substrate scope and the inapplicable to large-scale synthesis.Based on our research on Sadphos ligands,we present a Suzuki-Miyaura coupling reaction of alkoxy/arylphosphine oxybromide with arylboronic acids by using WJ-Phos as a chiral ligand,which could obtained the atropisomers phosphine oxides with up to 98% ee value.This reaction completed 100-g-scale synthesis without erosion of the ee value,which provided the possibility for industrial production.In addition,the obtained axial chiral biaryl monophosphine oxide can be used as a "platform molecule" for different functional group conversion,and the axial chiral biaryl monophosphine ligand obtained by reduction could be used in palladium-catalyzed asymmetric hydrosilylation of olefins.2.Copper-catalyzed cyclization reaction: synthesis of trifluoromethylated indolinyl ketonesOn account of the important value of trifluoromethylated indoline and the pioneering studies which have so far capitalized on the dearomative cycloaddition of the indole molecules.Herein,we report a novel synthetic method via copper-catalyzed cyclization reaction between N-alkylaniline and ?-(trifluoromethyl)-?,?-unsaturated enones,delivering the corresponding C-2 trifluoromethylated indolinyl ketones in high yields with up to > 20:1 dr.The control experiments elucidate that the reaction maybe involve a radical mechanism.Therefore,it is necessary to try new reaction system to realize the asymmetric catalysis.We screened the common monodentate or multidentate chiral phosphine ligands and Sadphos ligands,but did not deliver good results.3.Palladium-catalyzed syn-1,2-carboboration of alkenyl carbonyl compounds1,2-carboboration of alkenyl carbonyl compounds containing 8-aminoquinoline directing group is an effective means of concurrently forming C(sp3)-C and C(sp3)-B bond in a single step.It has been reported that the highly regioselective and diastereoselective carboboration and carbosilylation of alkenyl carbonyl compounds have been realized by the palladium-catalyzed Heck type 1,2-carboboration.But asymmetric catalysis of this reaction has not been realized.Based on the Sadphos,the 1,2-carboboration products of alkenyl carbonyl compounds could be obtained in 59% ee with the catalysis of palladium and Xu-Phos.The result of this reaction is still far from our goal,and we need to work hard to explore this reaction.