提出了羟基膦酸酯和氨基膦酸酯的绝对构型通过与市售萘普生的双衍生作用的分配。周围的立构碳中心的空间排列和Δδ的符号之间的相关性RS通过简单比较(R)-和(S)-萘普生酯或酰胺衍生物的1 H和31 P NMR光谱,可以确定羟基和氨基膦酸酯的绝对构型。NMR研究对结构多样的萘普生酯和羟基膦酸酯和氨基膦酸酯的酰胺进行了广泛的构象分析(理论计算,低温实验),证明了可以成功使用简化的模型。
Kinetic resolution of hydroxyalkanephosphonates catalyzed by Candida antarctica lipase B in organic media
作者:Yonghui Zhang、Chengye Yuan、Zuyi Li
DOI:10.1016/s0040-4020(02)00229-6
日期:2002.4
A series of hydroxyalkanephosphonates were studied as substrates for CALB catalyzed acetylation with emphasis on enantioselectivity and chemical structure of substrates. Some hydroxyalkanephosphonates could be resolved successfully to give both (R)- and (S)-isomers with high enantiomeric excess.
Novel diphosphines, their complexes with transisition metals and their use in asymmetric synthesis
申请人:——
公开号:US20040260101A1
公开(公告)日:2004-12-23
The invention relates to novel diphosphines, in optically pure or racemic form, of formula (I):
1
in which:
R
1
and R
2
are a (C
5
-C
7
)cycloalkyl group, an optionally substituted phenyl group or a 5-membered heteroaryl group; and
A is (CH
2
—CH
2
) or CF
2
.
The invention further relates to the use of a compound of formula (I) as a ligand for the preparation of a metal complex useful as a chiral catalyst in asymmetric catalysis, and to the chiral metal catalysts comprising at least one ligand of formula (I).
MeO-NAPhePHOS represents the first example of a new series of atropisomeric diphosphines bearing heterotopic biaryl moieties. The key step of its synthesis is the diastereoselective, intramolecular, Cu(I)-promoted coupling of 1-iodonaphthol and 2-iodo-3-methoxyphenol connected by a chiral tether. (R,R)-2,4-Pentanediol is used as the chiral auxiliary in this highly selective reaction that leads to a
Application of cyanobacteria for chiral phosphonate synthesis
作者:M. Górak、E. Żymańczyk-Duda
DOI:10.1039/c5gc01195g
日期:——
This is the first report on morphologically different strains of cyanobacteria: Arthrospira maxima, Nostoc cf-muscorum and Nodularia sphaerocarpa used for enantioselective bioreduction of selected, structurally different diethyl esters of oxophosphonic acids. The efficiency of the asymmetric hydrogen transfer was strongly dependent on the chemical structure of the substrates. Arthrospira maxima was active only toward diethyl (S)-2-oxopropylphosphonate (20% of yield, 99% of ee), whereas the application of Nostoc cf-muscorum as a biocatalyst allowed diethyl (S)-2-hydroxy-2-phenylethylphosphonate with a high enantiomeric excess (99%) and with 26% conversion degree to be obtained. Employing Nodularia sphaerocarpa led to the most spectacular result – diethyl (S)-2-hydroxy-2-phenylethylphosphonate with a degree of conversion of 99% and an optical purity of 92%. Enantioselective bioconversion of oxophosphonate with an aromatic side group located in the immediate vicinity of the carbonyl functionality was achieved for the first time. Additionally, flow cytometry showed excellent resistance of the cells of Nodularia sphaerocarpa against the examined xenobiotic – 2-oxo-2-phenylethylphosphonate, these cells remain viable at the concentration of 10 mM of the bioconversion substrate compared to the 1 mM described previously for a fungal biocatalyst. The effect of cultivation medium, light source and light cycle (light : dark) on the effectiveness of the biotransformation process was examined.
2-oxopropylphosphonate of R and S configuration and of high enantiomeric purity was obtained by stereocontrolled bioreduction using: Rhodotorula rubra, Rhodotorula glutinis, Rhodotorula gracilis and baker’s yeast. The effect of the addition of chemical compounds influencing the stereoselectivity of biotransformation have been investigated.