23204-84-4Relevant academic research and scientific papers
Engineering P450 Peroxygenase to Catalyze Highly Enantioselective Epoxidation of cis-β-Methylstyrenes
Zhang, Chun,Liu, Ping-Xian,Huang, Lu-Yi,Wei, Si-Ping,Wang, Li,Yang, Sheng-Yong,Yu, Xiao-Qi,Pu, Lin,Wang, Qin
supporting information, p. 10969 - 10975 (2016/07/27)
P450 119 peroxygenase and its site-directed mutants are discovered to catalyze the enantioselective epoxidation of methyl-substituted styrenes. Two new site-directed P450 119 mutants, namely T213Y and T213M, which were designed to improve the enantioselectivity and activity for the epoxidation of styrene and its methyl substituted derivatives, were studied. The T213M mutant is found to be the first engineered P450 peroxygenase that shows highly enantioselective epoxidation of cis-β-methylstyrenes, with up to 91 % ee. Molecular modeling studies provide insights into the different catalytic activity of the T213M mutant and the T213Y mutant in the epoxidation of cis-β-methylstyrene. The results of the calculations also contribute to a better understanding of the substrate specificity and configuration control for the regio- and stereoselective peroxygenation catalyzed by the T213M mutant.
A tandem Aldol-Grob reaction of ketones with aromatic aldehydes
Kabalka, George W.,Tejedor, David,Li, Nan-Sheng,Malladi, Rama R.,Trotman, Sarah
, p. 15525 - 15532 (2007/10/03)
Aromatic aldehydes react with ketones to produce (E)-1-aryl-1-alkenesvia a tandem Aldol-Grob cleavage reaction sequence. The reaction, initiated by boron trifluoride, also produces a carboxylic acid fragment.
Protonation and Alkykation of 1-Arylpropenyl-lithium
Tanaka, Jiro,Nojima, Masatomo,Kusabayashi, Shigekazu,Nagase, Shigeru
, p. 673 - 678 (2007/10/02)
The protonation and alkylation of 1-arylpropenyl-lithium (1a-c) in ether was undertaken systematically; the regio- and stereo-chemistry being influenced by various factors.The characteristic features are as follows. (a) Protonation occurs predominantly at C-3, whereas the sterically more crowded C-1 is the more favoured site for alkylation, and (b) although 1-arylpropenyl-lithium (1) seems to exist mainly as the E-isomer, in some cases the product (3) or (5) having the Z-configuration is produced from attack at C-3 in a significant amount together with the E-isomer, e.g. protonation by oxygen acids in the presence or absence of tetramethylethylenediamine and methylation of the p-methoxy derivative (1a).
WITTIG-REAKTION VON TRIPHENYLPHOSPHONIO-ALKYLIDEN MIT SUBSTITUIERTEN BENZALDEHYDEN: HAMMETT-BEZIEHUNG UND TEILWEISE REVERSIBILITAT DER ADDUKT-BILDUNG
Piskala, Alois,Rehan, Abdul Hamid,Schlosser, Manfred
, p. 3539 - 3551 (2007/10/02)
Bei Abwesenheit loslicher Lithium-Salze vereinigen sich Triphenylphosphonio-methylid und -ethylid bereits bei -75 deg C mit Aldehyden. Elektronenanziehende Liganden beschleunigen, elektronenspendende Liganden verzogern die Anlagerung der Ylide an die substituierten Benzaldehyde.Die Addukte(Oxaphosphetane) zerfallen erst oberhalb -30 deg C zu Olefin und Triphenylphosphinoxid.Wird vor dem Zerfall ein zweiter Aldehyd oder ein zweites Ylid zugesetzt, so findet ein teilweiser Austausch der Komponenten statt.
