A new route was developed for diastereoselective preparation of δ-(α-hydroxyalkyl)-αβ-unsaturated δ-lactones. A single diastereoisomer(14) of the lactone was obtained after oxidation and elimination of (12).
Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and p...Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as bio-blocks.The herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond activation.The synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.展开更多
In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxyg...In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation(HDO).Ethanolamine lactate ionic liquid(LAIL)exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin.Desired mono-condensation and bicondensation products were obtained with yield of 95.2%at 100℃.It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation.The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb_(2)O_(5)catalyst.The density of the obtained HDO products is 0.89 g/cm^(3)and the freezing point is lower than-60℃.These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels.展开更多
文摘A new route was developed for diastereoselective preparation of δ-(α-hydroxyalkyl)-αβ-unsaturated δ-lactones. A single diastereoisomer(14) of the lactone was obtained after oxidation and elimination of (12).
基金supported by National Natural Science Foundation of China(General Program,No.22372060)Shanghai Municipal Science and Technology Commission Project(No.22dz1209300)National Natural Science Youth Fund(No.22205065)。
文摘Ultra-long n-alkanes are highly valuable in both scientific research and as major constituents of specialty high-melting-point waxes.Unlike conventional methods(e.g.,Fischer–Tropsch(FT),ethylene oligomerization,and polyethylene cracking)typically resulting in wide n-alkane distributions,the elaborate design strategy presented herein allows the direct synthesis of pure,long n-alkanes using a modular splicing method with acetone,furfural,and fatty acid anhydrides or acyl chlorides as bio-blocks.The herein approach is based on a simple four-step catalytic reaction scheme involving C–C chain elongation and C–O bond activation.The synthesized pure n-alkanes had a carbon chain length as high as C_(49)(total yield of 49%).The synthesis approach also allows to selectively prepare n-alkanes with even and odd carbon numbers ranging from C15 to C_(49).This process represents a great breakthrough in the synthesis of long-chain pure n-alkanes,surpassing the carbon number limitations reported in previous methodologies.
基金funded by grants from the National Natural Science Foundation of China(No.52236010,51876210)the Fundamental Research Funds for the Central Universities(No.2242022R10058)。
文摘In this work,a“cyclopentanone-vanillin”strategy was proposed for the preparation of jet fuel range cycloalkanes from lignocellulose-derived ketones and lignin-derived aldehydes via aldol condensation and hydrodeoxygenation(HDO).Ethanolamine lactate ionic liquid(LAIL)exhibited excellent catalytic activity in the aldol condensation of cyclopentanone and vanillin.Desired mono-condensation and bicondensation products were obtained with yield of 95.2%at 100℃.It is found that the synergy effects between amino group of ethanolamine and hydroxyl group of lactic acid play a key role in the aldol condensation.The condensation products were converted into cycloalkanes by HDO over 5%Pd/Nb_(2)O_(5)catalyst.The density of the obtained HDO products is 0.89 g/cm^(3)and the freezing point is lower than-60℃.These results suggest that the resulted cycloalkanes can be used as additives to improve the density and low-temperature fluidity of the jet fuels.
