538-43-2Relevant articles and documents
Copper-Catalyzed Decarboxylative Alkylselenation of Propiolic Acids with Se Powder and Epoxides
Yao, Yujing,Wang, Caihong,Ma, Yunfei,Zhang, Jintao,Sun, Dong,Chen, Luya,Huang, Lehao,Wu, Ge
, p. 1930 - 1934 (2021)
A copper-catalyzed decarboxylative alkylselenation of propiolic acids with Se powder and epoxides leading to alkynyl selenides is developed. This protocol not only provides an approach to obtain alkynyl selenides with the formation of double C?Se bonds, but also expands the applicability of alkynyl carboxylic acid. (Figure presented.).
An Amphiphilic (salen)Co Complex – Utilizing Hydrophobic Interactions to Enhance the Efficiency of a Cooperative Catalyst
Solís-Mu?ana, Pablo,Salam, Joanne,Ren, Chloe Z.-J.,Carr, Bronte,Whitten, Andrew E.,Warr, Gregory G.,Chen, Jack L.-Y.
supporting information, p. 3207 - 3213 (2021/06/01)
An amphiphilic (salen)Co(III) complex is presented that accelerates the hydrolytic kinetic resolution (HKR) of epoxides almost 10 times faster than catalysts from commercially available sources. This was achieved by introducing hydrophobic chains that increase the rate of reaction in one of two ways – by enhancing cooperativity under homogeneous conditions, and increasing the interfacial area under biphasic reaction conditions. While numerous strategies have been employed to increase the efficiency of cooperative catalysts, the utilization of hydrophobic interactions is scarce. With the recent upsurge in green chemistry methods that conduct reactions ‘on water’ and at the oil-water interface, the introduction of hydrophobic interactions has potential to become a general strategy for enhancing the catalytic efficiency of cooperative catalytic systems. (Figure presented.).
Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
, p. 2795 - 2803 (2020/09/01)
A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and βR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM?1 s?1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM?1 s?1) for (R)-5a, whereas the kcat/Km (5.16 mM?1 s?1) for (S)-7a was much higher than that (0.09 mM?1 s?1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.
