Unprecedented Effects of Additives and Ligand-to-Metal Ratio on the Enantiofacial Selection of Copper-Catalyzed Alkynylation of α-Imino Ester with Arylacetylenes
作者:Zhihui Shao、Jun Wang、Kai Ding、Albert S. C. Chan
DOI:10.1002/adsc.200700237
日期:2007.10.8
The first catalytic asymmetric addition of arylacetylenes to α-iminoesters was carried out using chiral copper(I) complexes as catalysts under mild reaction conditions, providing the corresponding alkynylation products in good yields with 67–74 % ee values. Profound effects of the ligand-to-metalratio and additives on the stereofacial selection were observed. Both enantiomers of a given product can
enantioselective synthesis of chiral fluorinated propargylamines was developed through phosphoric acid and ruthenium-catalyzed chemoselective biomimetic hydrogenation of the carbon–nitrogen double bond of fluorinated alkynyl ketimines in the presence of a carbon–carbon triple bond. This reaction features high chemoselectivity and slow background reaction. In addition, selective transformations of the chiral fluorinated
reaction of ethyl glyoxylate, para-anisidine, and aliphatic, aromatic alkynes catalyzed by CuOTf·0.5C6H6/pybox 7 has been developed. The protocol provided the corresponding chiral β,γ-alkynyl α-amino acidderivatives in good yields and 66–74% ee.
已经开发了CuOTf·0.5C 6 H 6 / pybox 7催化的乙醛酸乙酯,对茴香胺和脂肪族,芳族炔烃的第一催化不对称三组分反应。该方案以高收率和66-74%ee提供了相应的手性β,γ-炔基α-氨基酸衍生物。
Copper-Catalyzed Aerobic Enantioselective Cross-Dehydrogenative Coupling of <i>N</i>-Aryl Glycine Esters with Terminal Alkynes
作者:Zhiyu Xie、Xigong Liu、Lei Liu
DOI:10.1021/acs.orglett.6b01328
日期:2016.6.17
A copper-catalyzed enantioselective cross-coupling of a Csp3–H moiety (N-aryl glycine ester) with a Csp–H component (terminal alkyne) using molecular oxygen as the terminal oxidant is described for the first time. The sustainable method provides an efficient and environmentally friendly approach to rapidly prepare a diverse array of optically active non-natural α-amino acids.