Exploring the Scope of an α/β-Aminomutase for the Amination of Cinnamate Epoxides to Arylserines and Arylisoserines
作者:Prakash K. Shee、Nishanka Dilini Ratnayake、Tyler Walter、Olivia Goethe、Edith Ndubuaku Onyeozili、Kevin D. Walker
DOI:10.1021/acscatal.9b01557
日期:2019.8.2
signals confirmed the diastereomeric ratios and relative stereochemistries. Application of a (2S)-threonine aldolase from E. coli further established the absolute stereochemistry of the chiral derivatives of the diastereomeric enzymatically derived products. The 2R:2S ratio for the biocatalyzed anti-isomers was highest (88:12) for 3′-NO2-phenylserine and lowest (66:34) for 4′-F-phenylserine. This showed
Gold(I)-catalyzed asymmetric aldol reactions of isocyanoacetic acid derivatives with fluoroaryl aldehydes
作者:Vadim A. Soloshonok、Alexey D. Kacharov、Tamio Hayashi
DOI:10.1016/0040-4020(95)00893-d
日期:1996.1
enantiomeric excess (up to 63% of cis with 86–90% ee). In contrast to this, aldolreactions of isocyanoacetamide with fluoro-benzaldehydes provide dominant formation of trans-oxazolines (77–92% of trans with 80–94% ee) in all cases studied. The observed unusual stereodifferentiation in the reaction of methylisocyanoacetate with polyfluorobenzaldehydes is rationalized on the basis of an electron donor—acceptor
Gold(I)-catalyzed asymmetric aldol reaction of methyl isocyanoacetate with fluorinated benzaldehydes
作者:Vadim A. Soloshonok、Tamio Hayashi
DOI:10.1016/s0040-4039(00)77013-4
日期:1994.4
In the title reaction, successive substitution of hydrogen atoms in the phenyl ring of benzaldehyde by fluorine atoms brought about gradual alteration of both diastereo- and enantioselectivities in the corresponding oxazolines formation. The highest values for the unusual selectivity (up to 63% cis with 86–90% ee) were observed in the reaction of tetrafluoro- and pentafluorobenzaldehydes.
Improving and Inverting C<sub>β</sub>-Stereoselectivity of Threonine Aldolase via Substrate-Binding-Guided Mutagenesis and a Stepwise Visual Screening
作者:Qijia Chen、Xi Chen、Jinhui Feng、Qiaqing Wu、Dunming Zhu、Yanhe Ma
DOI:10.1021/acscatal.9b00859
日期:2019.5.3
Threoninealdolase (TA)-catalyzed aldol condensation is a powerful tool for C–C bond formation under mild conditions, but the low Cβ-stereoselectivity has hampered its wide application. A stepwise visual screening method was developed to measure the activity and stereoselectivity of threonine aldolase-catalyzed aldol condensation by employing a stereoselective phenylserine dehydratase, enabling direct
Stereoselektive Synthesen der diastereomeren D,L-3-(p-Fluorphenyl)-serine und -isoserine
作者:N. Blažević、F. Zymalkowski
DOI:10.1002/ardp.19753080709
日期:——
Für die Titelverbindungen, die chemotherapeutische Aktivität erwarten lassen, werden gezielte Synthesender jeweiligen threo‐ und erythro‐Formen beschrieben.