Studies On The Synthesis And Catalytic Properties Of Poss Supported C₂-symmetric Bisprolinamide Chiral Catalysts

C₂-symmetric bisprolinamide is a kind of effective chiral catalysts,are widely used in catalytic asymmetric Aldol reaction,Diels-Alder reactions,and achieved good catalytic effect.In order to facilitate the separation and purification,and to give branched supported carrying catalyst,to obtain a good catalytic performance.polyhedral oligomeric silsesquioxane（POSS）is a novel organic-inorganic hybrid materials with nanoscale dimensions,and good thermal stability and good solubility versatility and carrying capacity and support.It as a soluble carrier,supported catalyst to catalyst reaction under homogeneous conditions,and to obtain good supported results.Based the structure Features of C₂-symmetric bisprolinamide and POSS,the C₂-symmetric bisprolinamide as the soluble support to supported C₂-symmetric bisprolinamide chiral catalysts to catalytic asymmetric Aldol addition reaction.Firstly,phenyltrimethoxysilane as a raw material obtained by hydrolysis condensation containing seven uncapped phenyl POSS sodium salt,sodium salt and then POSS 3-bromopropyl trichlorosilane "apex-cap" to give a single functional groups POSS-Br,single angle POSS-Br reacted with NaN3 single angle POSS-N3,yield 37%.Phenyltrimethoxysilane containing material obtained by hydrolysis condensation of eight uncapped ends phenyl POSS sodium salt,sodium salt and then POSS methyldichlorosilane a "cap" bifunctional POSS obtained,yield 32%Secondly,Boc-L-hydroxyproline as starting material,is reacted with 3-bromo-propyne,the introduction of an acetylenic bond in the molecular structure,and then with 1,2-phenylene diamine amidation reaction,to give a little prolinamide molecule,and finally took off Boc protected amino role in TFA to give small molecule C₂-symmetrical bisprolinamide chiral catalysts.Third,the C₂-symmetric prolinamide small molecule catalysts with a single horn POSS-N3 alkyne-containing double bonds were reacted to obtain a single horn Click POSS-supported C₂-symmetric bisprolinamide chiral catalysts,yield 78-80%;containing Boc of C₂-symmetric bisprolinamide small molecule with two horns POSS hydrosilylation polymer obtained by hydrosilylation reaction,TFA off at the role of Boc protected amino,to give bis double-prolinamide polymer chiral catalysts,yield angle POSS supported C₂-symmetric 90-92%.POSS-supported C₂-symmetric bisprolinamide chiral catalyst in methylene chloride,chloroform,tetrahydrofuran,N,N-dimethylformamide,soluble in a solvent,while in petroleum ether,diethyl ether,methyl t butyl ether solvent insoluble to facilitate separation and purification after the catalytic reaction based on differences in solubility of the catalyst.Fourth,tin trifluoromethanesulfonate additive,in an amount of 5 mol%,and water as the solvent in DMF 1 mL（9/1）,the reaction temperature is 25℃,with 5 mol%of one-hand corner POSS-supported of C₂-symmetric double-prolinamide catalyst,heterogeneous catalytic asymmetric ketones and aromatic aldehydes Aldol reaction 20 h,at a yield of 5-85%,dr value 52:48-95:5,ee value of 59.5-97.9%.Methyl tert-butyl ether by weight crystallized achieve recovery of the catalyst,the recovery is around 90%recycled five times,three-dimensional product selectivity and yield no significant decline.Formic acid as an additive,in an amount of 150 mol%.the reaction temperature is 0 ℃,with 15 mol C₂-symmetrical double-prolinamide%polymer horns POSS-supported,heterogeneous catalytic asymmetric ketone ketone esters and a-Aldol reaction 18 h,at a yield of 35-83%,ee value of 83.8-85.5%.Methyl tert-butyl ether by weight crystallized achieve recovery of the catalyst,the recovery is around 90%recycled four times,three-dimensional product selectivity and yield no significant decline.Fifth,we use the IR,^H NMR,¹³C NMR,²⁹Si NMR to analysis the structure of these compounds,and the resulting data is consistent with the structure.In this article,was successfully prepared soluble single POSS supported C₂-symmetric bisprolinamide chiral catalysts and C₂-symmetric bisprolinamide polymer chiral catalysts,to catalytic asymmetric Aldol reaction and acpuire good effect supported and catalytic effects.