Asymmetric Iodoamination of Chalcones and 4-Aryl-4-oxobutenoates Catalyzed by a Complex Based on Scandium(III) and a N,N′-Dioxide Ligand

被引：79

作者：

Cai, Yunfei ^{[1
]}

Liu, Xiaohua ^{[1
]}

Li, Jun ^{[1
]}

Chen, Weiliang ^{[1
]}

Wang, Wentao ^{[1
]}

Lin, Lili ^{[1
]}

Feng, Xiaoming ^{[1
]}

机构：

[1] Sichuan Univ, Coll Chem, Minist Educ, Key Lab Green Chem & Technol, Chengdu 610064, Peoples R China

来源：

CHEMISTRY-A EUROPEAN JOURNAL | 2011年 / 17卷 / 52期

基金：

中国国家自然科学基金;

关键词：

asymmetric catalysis; dioxides; iodoamination; iodonium ions; scandium; STEREOSELECTIVE AMINOBROMINATION; AMINOHALOGENATION REACTION; ELECTROPHILIC DIAMINATION; NITROGEN; OLEFINS; ALKENES; TSNH2; NBS; AMINOCHLORINATION; CHLOROAMINATION;

D O I：

10.1002/chem.201102453

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Highly diastereo- and enantioselective iodoamination of chalcones, 4-aryl-4-oxobutenoates, and a trifluoro-substituted enone has been accomplished in the presence of a chiral N,N'-dioxide/[Sc(OTf)3] complex (0.52 mol%), delivering the desired vicinal anti-alpha-iodo-beta-amino carbonyl compounds regioselectively in high yields (up to 97%) and with excellent diastereoselectivities (>99:1 d.r.) and enantioselectivities (up to 99% ee). Enantiopure syn-alpha-iodo-beta-amino products could also be obtained from the isomerization of particular iodo compounds. TsNHX species (X=Cl, Br, I), generated from the reactions between the halo sources and TsNH2, were further confirmed as the active species in the haloamination reactions involved in the formation of the key halonium ion intermediates. A typical haloamination dependency was observed, with reactivity decreasing in the order NBS>NIS >> NCS.

引用

页码：14916 / 14921

页数：6

共 51 条

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