通过逐步延伸法制备用于具有确定聚合度的查耳酮的 Julia-Colonna 不对称环氧化反应的催化剂低聚-L-亮氨酸。环氧化反应的产率和对映选择性随着催化剂聚合度的增加而增加。N-末端未保护的胺部分的存在证明对于高不对称诱导是必不可少的。催化剂的 IR 特征吸收带(酰胺 I 区)表明催化剂中的螺旋结构与不对称诱导有关。
Mechanism study on the Oligomerization of Amino Acids into Peptides by Phosphorus Trichloride
作者:Wenjie Zhao、Dongxin Zhao、Kui Lu
DOI:10.1080/10426500701807467
日期:2008.1.14
As treated by phosphorustrichloride, amino acids could oligomerize into polypeptides. Based on the results obtained by 31P-NMR and ESI-MS/MS, a possible reaction mechanism was proposed. The mechanism might undergo a penta-coordinated phosphorus intermediat. The activated amino acid was a five-membered cyclic penta-coordinated phosphorus intermediate. The nucleophilic attack of the amino group from
The Juliá-Colonna Asymmetric Epoxidation Reaction of Chalcone Catalyzed by Length Defined Oligo-<b>L</b>-leucine: Importance of the<b><i>N</i></b>-Terminal Functional Group and Helical Structure of the Catalyst in the Asymmetric Induction
oligo-L-leucine, for the Julia-Colonnaasymmetricepoxidation of chalcone with defined degrees of polymerization were prepared by a stepwise elongation method. The yield and enantioselectivity in the epoxidation increased with the degree of polymerization of the catalyst. The presence of an unprotected amine moiety at the N-terminus proved to be essential for high asymmetric induction. The IR characteristic
通过逐步延伸法制备用于具有确定聚合度的查耳酮的 Julia-Colonna 不对称环氧化反应的催化剂低聚-L-亮氨酸。环氧化反应的产率和对映选择性随着催化剂聚合度的增加而增加。N-末端未保护的胺部分的存在证明对于高不对称诱导是必不可少的。催化剂的 IR 特征吸收带(酰胺 I 区)表明催化剂中的螺旋结构与不对称诱导有关。