Stereodivergent Synthesis of α,α-Disubstituted α-Amino Acids via Synergistic Cu/Ir Catalysis
作者:Liang Wei、Qiao Zhu、Shi-Ming Xu、Xin Chang、Chun-Jiang Wang
DOI:10.1021/jacs.7b12174
日期:2018.1.31
Cu/Ir dualcatalysis has been developed for the stereodivergent α-allylation of aldimine esters. The method enables the preparation of a series of nonproteinogenic α-amino acids (α-AAs) bearing two contiguous stereogenic centers in high yield with excellent stereoselectivity. All four product stereoisomers could be obtained from the same set of starting materials via pairwise combination of two chiral
Synergistic Cu/Pd‐Catalyzed Asymmetric Allenylic Alkylation of Azomethine Ylides for the Construction of α‐Allene‐Substituted Nonproteinogenic α‐Amino Acids
作者:Hua‐Chao Liu、Yuan‐Zheng Hu、Zuo‐Fei Wang、Hai‐Yan Tao、Chun‐Jiang Wang
DOI:10.1002/chem.201901046
日期:——
This dual catalytic system possesses good substrate compatibility, delivering a diverse array of nonproteinogenic α‐allenylic α‐mono‐ or α,α‐disubstituted α‐aminoacids (α‐AAs) with high yields and generally excellent enantioselectivities. Furthermore, the scalability and practicability of the current synthetic protocol were proven by performing gram‐scale reactions and by the first catalytic asymmetric
Copper(II)salen catalysed, asymmetric synthesis of α,α-disubstituted amino acids
作者:Yuri N Belokon、Devayani Bhave、Daniela D'Addario、Elisabetta Groaz、Michael North、Valeria Tagliazucca
DOI:10.1016/j.tet.2003.12.031
日期:2004.2
Cu(salen) complex 1 was found to be a versatile catalyst for the asymmetric alkylation of a range of enolates derived from α-amino acids, leading to α,α-disubstituted amino acids. The enantioselectivity of the process decreases as the size of the amino acid sidechain increases, but functionalized amino acids such as allylglycine and aspartic acid are substrates for the process. Benzylic bromides are
The 1,3-dipolar cycloaddition of 2-aryl-3-nitrochromenes with various azomethine ylides has been investigated. The structure and stereochemistry of cycloadducts were studied in detail by NMR spectroscopic methods.
Catalytic, asymmetric synthesis of α,α-disubstituted amino acids
作者:Yuri N. Belokon’、Devayani Bhave、Daniela D'Addario、Elizabetta Groaz、Viktor Maleev、Michael North、Armine Pertrosyan
DOI:10.1016/s0040-4039(03)00170-9
日期:2003.3
Copper(salen) complex 1 has been found to catalyse the asymmetric alkylation of enolates derived from a variety of aminoacids. There is a clear relationship between the size of the side chain in the substrate and the enantioselectivity of the process, so that the enantioselectivity decreases in the order alanine>aminobutyric acid>allylglycine>leucine>phenylalanine>valine. A transition state model