Cp<sub>2</sub>TiCl<sub>2</sub>-catalyzed hydrocarboxylation of alkynes with CO<sub>2</sub>: formation of α,β-unsaturated carboxylic acids
作者:Peng Shao、Sheng Wang、Gaixia Du、Chanjuan Xi
DOI:10.1039/c6ra25003c
日期:——
Cp2TiCl2-catalyzed hydrocarboxylation of alkynes with CO2 (atmospheric pressure) has been reported. A range of alkynes were transformed to the corresponding α,β-unsaturatedcarboxylicacids in high yields with high regioselectivity. The reaction proceeded with hydrotitanation, transmetalation, and subsequently carboxylation with CO2.
The synergistic copper/ppm Pd-catalyzed hydrocarboxylation of alkynes with formic acid as a CO surrogate as well as a hydrogen source: an alternative indirect utilization of CO<sub>2</sub>
作者:Shu-Mei Xia、Zhi-Wen Yang、Xiang-Yang Yao、Kai-Hong Chen、Li-Qi Qiu、Liang-Nian He
DOI:10.1039/d1gc02735b
日期:——
An unprecedented strategy has been developed involving the earth-abundant Cu-catalyzed hydrocarboxylation of alkynes with HCOOH to (E)-acrylic derivatives with high regio- and stereoselectivity via synergistic effects with ppm levels of a Pd catalyst. Both symmetrical and unsymmetrical alkynes bearing various functional groups were successfully hydrocarboxylated with HCOOH, and the modification of
已经开发了一种前所未有的策略,涉及通过与 Pd 催化剂的 ppm 水平的协同效应,用 HCOOH 将地球上丰富的 Cu 催化的炔烃加氢羧化为具有高区域和立体选择性的( E )-丙烯酸衍生物。带有各种官能团的对称和不对称炔烃均成功地被 HCOOH 烃基化,药物分子的修饰体现了该过程的实用性。该协议采用 HCOOH 作为 CO 替代物和氢供体,具有 100% 的原子经济性,可以将其视为间接 CO 2使用的替代方法。机理研究表明 Cu/ppm Pd 协同催化机制通过烯基铜物种作为潜在的中间体,由铜氢化物活性催化物种形成,HCOOH 作为氢源。这种包含廉价 Cu 和痕量 Pd 的双金属系统提供了一种可靠且有效的加氢羧化方法,以 HCOOH 作为氢源获得工业上有用的丙烯酸衍生物,并为优化其他与 Cu-H 相关的助催化系统提供了新的线索。
Up to 96% Enantioselectivities in the Hydrogenation of Fluorine Substituted (E)-2,3-Diphenylpropenoic Acids over Cinchonidine-Modified Palladium Catalyst
High enantioselectivities, up to 96%, were obtained in the hydrogenation of some disubstituted derivatives, unprecedented in the hydrogenation of prochiral unsaturated carboxylicacidsovermodified heterogeneous catalyst. The best optical purities were reached in the hydrogenation of derivates bearing a para-substituent on the β phenyl and an ortho-substituent on the α phenyl ring, respectively. The
Efficient hydrocarboxylation of alkynes based on carbodiimide-regulated in situ CO generation from HCOOH: An alternative indirect utilization of CO2
作者:Shu-Mei Xia、Zhi-Wen Yang、Kai-Hong Chen、Ning Wang、Liang-Nian He
DOI:10.1016/s1872-2067(21)63848-2
日期:2022.7
operating toxic CO and circumventing sensitivity issue to the CO amount. On the basis of the attractive features of formic acid including easy preparation through CO2 hydrogenation and efficient liberation of CO, this protocol using formic acid as bridging reagent between CO2 and CO can be perceived as an indirect utilization of CO2, offering an alternative method for preparing acrylic acid analogues.
Asymmetric transfer hydrogenation of 2,3-diphenylpropenoic acids over heterogeneous palladium catalysts modified by cinchona alkaloids
作者:György Szőllősi、Vivien Erzsébet Resch、Vanessza Judit Kolcsár
DOI:10.1016/j.jcat.2024.115290
日期:2024.1
supported palladium catalysts modified by dihydrocinchonidine carried out in ordinary laboratory glassware using easily available, cheap hydrogen donor, potassium formate. High conversions and good enantioselectivities were obtained in transfer hydrogenations of various acids substituted on phenyl rings. Results obtained with various acid derivatives and with few cinchona alkaloid modifiers indicated that