Study On Green Synthesis Of Organic Borate And Cobalt-catalyzed Phosphorus(Ⅲ) Directed C-H Activation

Organoboron compounds are an important class of synthetic intermediates,and they are one of the basic synthetic units of drug molecules and new materials.Among them,the synthesis of alkyl boron compounds is challenging.This work,based on the 1,2-boron migration strategy,is the first application of methylating reagent—MTT in the synthesis of benzyl boron compounds,the reaction starts from commercial boric acid esters,only using potassium tert-butoxide as a base,and dichloromethane and toluene as a mixed solvent.The reaction system is simple to operate and mild in conditions.Finally,we have completed the synthesis of a series of benzyl boronic esters with different electrical and sterically hindered substituents.Incorporating deuterium atoms into organic molecules to adjust the stability of drugs and improve the pharmacokinetic properties has become one of the research hotspots in medicinal chemistry.In addition,given that alkyl boron compounds are a class of important synthetic intermediates,the incorporation of deuterium atoms into borides is of great significance.At present,the synthesis of alkyl boron compounds containing deuterium atoms has not been reported.Based on the previous work,we used the deuterated methylation reagent DMTT,for the first time to achieve the D2-benzylic boronates.On the other hand,the operation is simple and the product has broad application value,At the same time,a series of derivatization studies were carried out for the deuterated products,and the conversion was excellentC-H bond activation functionalization catalyzed by transition metals has been one of the hotspots in the field of inert bond activation.O and N-chelation assisted unsaturated bonds hydroarylation have been the appropriate choice of the directing group.However,as a variant of that,catalytic PⅢ-chelated hydroarylation of alkenes remains a challenge.This work uses trivalent phosphine guide group,under the catalysis of cheap metal cobalt,with the catalytic amount of NHC ligand,LiOtBu as base,TMSCH2MgCl as reducing agent,to achieve the hydroarylation of commercial monphosphine ligands(2-diphenylphosphine-biphenyl)and styrene compounds.We synthesized a series of linear alkylation products with different electrical and steric resistance,which greatly enriched the phosphine ligand library.The reaction system has a low cost,excellent yield and good functional group tolerance.