1885-07-0Relevant articles and documents
Enhanced enantioselectivity in heterogeneous manganese-catalyzed asymmetric epoxidation with nanosheets modified amino acid Schiff bases as ligands by modulating the orientation and the arrangement order
An, Zhe,Han, Hongbo,He, Jing,Jiang, Yitao,Ping, Qi,Shu, Xin,Song, Hongyan,Tang, Yuanzhong,Wang, Wenlong,Xiang, Xu,Zhu, Yanru
, p. 22 - 36 (2021/08/25)
Catalytic enantioselective epoxidation of olefins plays an important role in the production of optically-active epoxy. Transition-metal complexes prove efficient for the catalytic epoxidation of un-functionalized olefins by employing privileged chiral lig
Enantiocomplementary Epoxidation Reactions Catalyzed by an Engineered Cofactor-Independent Non-natural Peroxygenase
Crotti, Michele,Kataja, Kim M.,Poelarends, Gerrit J.,Saravanan, Thangavelu,Xu, Guangcai
, p. 10374 - 10378 (2020/04/23)
Peroxygenases are heme-dependent enzymes that use peroxide-borne oxygen to catalyze a wide range of oxyfunctionalization reactions. Herein, we report the engineering of an unusual cofactor-independent peroxygenase based on a promiscuous tautomerase that accepts different hydroperoxides (t-BuOOH and H2O2) to accomplish enantiocomplementary epoxidations of various α,β-unsaturated aldehydes (citral and substituted cinnamaldehydes), providing access to both enantiomers of the corresponding α,β-epoxy-aldehydes. High conversions (up to 98 %), high enantioselectivity (up to 98 % ee), and good product yields (50–80 %) were achieved. The reactions likely proceed via a reactive enzyme-bound iminium ion intermediate, allowing tweaking of the enzyme's activity and selectivity by protein engineering. Our results underscore the potential of catalytic promiscuity for the engineering of new cofactor-independent oxidative enzymes.
A highly stereoselective synthesis of glycidic amides based on a new class of chiral sulfonium salts: Applications in asymmetric synthesis
Sarabia, Francisco,Vivar-García, Carlos,García-Castro, Miguel,García-Ruiz, Cristina,Martín-Gálvez, Francisca,Sánchez-Ruiz, Antonio,Chammaa, Samy
supporting information, p. 15190 - 15201 (2013/01/15)
A new type of chiral sulfonium salts that are characterized by a bicyclic system has been designed and synthesized from α-amino acids. Their corresponding ylides, which were prepared by basic treatment of the sulfonium salts, reacted smoothly with a broad array of simple and chiral aldehydes to provide trans-epoxy amides in reasonable to very good yields and excellent stereoselectivities (>98 %). The obtained epoxy amides were found to be useful as synthetic building blocks. Thus, they were reduced into their corresponding epoxy alcohols and subjected to oxirane-ring-opening reactions with different types of nucleophiles.
