874948-60-4Relevant articles and documents
Hypercrosslinking chiral Br?nsted acids into porous organic polymers for efficient heterogeneous asymmetric organosynthesis
Jia, Ji,Liu, Xiaoming,Ma, Si,Xia, Hong,Zhang, Yuwei,Zhang, Zhenwei
supporting information, p. 25369 - 25373 (2021/12/07)
Here, we developed a construction strategy for directly immobilizing the axially chiral phosphoric acid into hypercrosslinked polymers by a one-pot Friedel-Crafts alkylation reaction. The obtained chiral polymers have high porosity, excellent stability and tailorable catalytic centers, and display excellent activity, enantioselectivity and recyclability for asymmetric transfer hydrogenation.
Biomimetic asymmetric 1,3-dioplar cycloaddition: Amino acid precursors in biosynthesis serve as latent azomethine ylides
Guo, Chang,Song, Jin,Gong, Liu-Zhu
supporting information, p. 2676 - 2679 (2013/07/19)
The first asymmetric catalytic biomimetic three-component 1,3-dipolar cycloaddition of α-keto esters and benzylamine with electron-deficient olefins, inspired by the transamination of α-keto acids involving pyridoxal phosphate (PLP)-dependent enzymes in biological systems, giving several families of structurally diverse pyrrolidine derivatives in high yields and excellent enantioselectivities (up to 99% ee) under mild conditions is described.
Facile and efficient enantioselective strecker reaction of ketimines by chiral sodium phosphate
Shen, Ke,Liu, Xiaohua,Cai, Yunfei,Lin, Lili,Feng, Xiaoming
supporting information; scheme or table, p. 6008 - 6014 (2010/02/28)
A facile and efficient enantioselective Strecker reaction of ketimines catalyzed by a chiral alkali-metal salt has been developed. When 10 mol% BNPNa (BNP=1,1'-binaphthyl-2,2'-diylphosphate) prepared in situ and 10 mol% para-tert-butylortho-adamantylphenol (PBAP) were introduced into the reaction, up to 96% yield and up to 95% ee (ee=enantiomeric excess) were obtained. Both aliphatic and aromatic ketimines, especially sterically bulky cyclic ketimines derived from β-acetonaphthone, α-indanone, and α-tetralone were found suitable for this reaction. On the basis of the experimental results and previous reports, trimethylsilyl cyanide (TMSCN) was indicated to be the real reactive nucleophile despite the existence of PBAP, and a possible working model was proposed to explain the origin of the asymmetric induction. The facile availability of 1,1'-binaphthyl-2,2'-diylphosphoric acid (BNPH) and the simplicity of the procedure are beneficial for practical applications.