摘要:
A method that manufacturers an optically active carboxylic acid ester at high yield and high enantioselectivity is provided. An optically active carboxylic acid ester is manufactured at high yield and high enantioselectivity by reacting a racemic carboxylic acid and a specific alcohol or phenol derivatives in a polar solvent having a dipole moment of 3.0 or higher in the presence of an acid anhydride and an asymmetric catalyst, esterifying one enantiomer of the racemic carboxylic acid at high selectivity, and increasing the amount of esterified carboxylic acid by racemizing the optically active carboxylic acid which is the other enantiomer not used in esterification.
摘要:
A method for synthesizing of thioesters by using a compound as a catalyst is disclosed. The compound is represented by formula I below: In formula I, R5 represents H, a substituted or unsubstituted alkyl, a substituted or unsubstituted aryl, or a substituted or unsubstituted heteroaryl; X and Y each independently represents one of H, C1-10 alkyl, C5-10 aryl, C1-10 alkyl alcohol, thiohydroxy, carbonyl, sulfonyl, sulfamoyl, carbamoyl, C1-10 alkoxycarbonyl, C1-10 alkoxycarbamoyl, C1-10 alkylamino, C1-10 alkylsulfonyl, C1-10 haloalkylsulfonyl, ureido, amido, and C1-10 alkoxylcarbamoyl; and n is 0, 1, 2, 3, 4 or 5.
摘要:
Methods are provided for modifying hydrogenation catalysts having silica supports (or other non-alumina supports) with additional alumina, and using such catalysts to achieve unexpectedly superior hydrogenation of feedstocks. The modified hydrogenation catalysts can have a relatively low cracking activity while providing an increased activity for hydrogenation.
摘要:
A method that manufacturers an optically active carboxylic acid ester at high yield and high enantioselectivity is provided. An optically active carboxylic acid ester is manufactured at high yield and high enantioselectivity by reacting a racemic carboxylic acid and a specific alcohol or phenol derivatives in a polar solvent having a dipole moment of 3.0 or higher in the presence of an acid anhydride and an asymmetric catalyst, esterifying one enantiomer of the racemic carboxylic acid at high selectivity, and increasing the amount of esterified carboxylic acid by racemizing the optically active carboxylic acid which is the other enantiomer not used in esterification.
摘要:
The present invention provides a bifunctional catalyst of the formula (1): wherein: each R1 is independently selected from an optionally substituted alkyl group, an optionally substituted cycloalkyl group, an optionally substituted aryl group, an optionally substituted heteroaryl group, an optionally substituted aralkyl group and an optionally substituted alkaryl group; Z represents a divalent organic linking moiety optionally containing one or more stereocentres; and EWG represents an electron-withdrawing group. (R1)3P═N—Z—NH-EWG (1)
摘要:
A method of preparing an oligomeric or polymeric compound in a liquid solution is disclosed which consists of reacting a Michael donor compound with a Michael acceptor compound in the presence of a first catalyst and a Group IA and/or Group IIA metal ion catalyst.
摘要:
The present invention provides a novel catalyst system which can be preferably used in the trimerization, oligomerization reaction or polymerization reaction of an olefin, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system. A catalyst system obtained by contacting the following components (A) to (C):(A) a chromium compound,(B) an imine compound, and(C) a metal alkyl compound, and a method for the trimerization, oligomerization or polymerization reaction of an olefin, which comprises using the catalyst system are disclosed.
摘要:
This invention relates to the manufacture of such valuable chemicals as polyhydric alcohols, their ether and ester derivatives, oligomers of such alcohols and monohydric alcohols and their ether and ester derivatives by reacting oxides of carbon and hydrogen in the presence of a bis(triorgano phosphine)iminium cation and a rhodium carbonyl complex provided to the reaction as a rhodium carbonyl cluster anion which possesses an infrared spectrum which exhibits three intense wavelength bands between about plus and minus 10 cm.sup.-.sup.1 of about 1868 cm.sup.-.sup.1, about 1838 cm.sup.-.sup.1, and about 1785 cm.sup.-.sup.1 at a pressure of at least about 500 pounds per square inch absolute.
摘要翻译:本发明涉及在双(三有机膦)存在下,通过使碳和氢的氧化物反应来制造这种有价值的化学物质,如多元醇,它们的醚和酯衍生物,这些醇和一元醇的低聚物及其醚和酯衍生物, 亚胺鎓阳离子和铑羰基络合物,其作为具有红外光谱的铑羰基簇阴离子提供给反应,该红外光谱在约1868cm -1的约+ 10cm -1之间呈现出三个强的波长带,约1838cm -1 cm -1至约1785cm -1,压力为至少约500磅/平方英寸绝对压力。
摘要:
The present invention relates to a hybrid nanostructured photocatalyst, comprising a first nanoparticle comprising silver halide (AgX); a second nanoparticle, which is formed on an outer surface of the first nanoparticle and comprises Ag; and a polymer formed on any one outer surface of the first nanoparticle and the second nanoparticle, and a preparation method thereof. Specifically, the present invention provides a hybrid nanostructured photocatalyst having a high photocatalytic activity in a visible light region and a preparation method thereof.
摘要:
Methods are provided for modifying hydrogenation catalysts having silica supports (or other non-alumina supports) with additional alumina, and using such catalysts to achieve unexpectedly superior hydrogenation of feedstocks. The modified hydrogenation catalysts can have a relatively low cracking activity while providing an increased activity for hydrogenation.