1,2-Oxazine N-Oxides as Catalyst Resting States in Michael Additions of Aldehydes to Nitro Olefins Organocatalyzed by α,α-Diphenylprolinol Trimethylsilyl Ether

被引：51

作者：

Seebach, Dieter ^{[1
]}

Sun, Xiaoyu ^{[1
]}

Sparr, Christof ^{[1
]}

Ebert, Marc-Olivier ^{[1
]}

Schweizer, W. Bernd ^{[1
]}

Beck, Albert K. ^{[1
]}

机构：

[1] ETH, Organ Chem Lab, Dept Chem & Angew Biowissensch, Honggerberg HCI, CH-8093 Zurich, Switzerland

来源：

HELVETICA CHIMICA ACTA | 2012年 / 95卷 / 07期

关键词：

1; 2-Oxazine N-oxides; Enamines; Nitro olefins; Organocatalysis; Hayashi catalyst; Catalysis; Michael addition; X-Ray crystallography; X-RAY-CRYSTAL; CONJUGATE ADDITION; ENOL ETHERS; ENANTIOSELECTIVE ALKYLATIONS; METHYL-ETHER; NMR-SOLUTION; ENAMINES; CYCLOADDITIONS; EQUILIBRIUM; ESTERS;

D O I：

10.1002/hlca.201200283

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

By combining enamines, derived from aldehydes and diphenylprolinol trimethylsilyl ether (the Hayashi catalyst), with nitroethenes ((D6)benzene, 4-angstrom molecular sieves, room temperature) intermediates of the corresponding catalytic Michael-addition cycles were formed and characterized (IR, NMR, X-ray analysis; Schemes 36 and Fig. 13). Besides cyclobutanes 2, 1,2-oxazine N-oxide derivatives 36 and 8 have been identified for the first time, some of which are very stable compounds. It may not be a lack of reactivity (between the intermediate enamines and nitro olefins) that leads to failure of the catalytic reactions (Schemes 35) but the high stability of catalyst resting states. The central role zwitterions play in these processes is discussed (Schemes 1 and 2).

引用

页码：1064 / 1078

页数：15

共 39 条

[1] ASYMMETRIC MICHAEL-ADDITIONS - PRACTICALLY COMPLETELY DIASTEREOSELECTIVE AND ENANTIOSELECTIVE ALKYLATIONS OF THE ENAMINE FROM CYCLOHEXANONE AND PROLINYL METHYL-ETHER BY OMEGA-NITROSTYRENES TO GIVE U- 2-(1'-ARYL-2'-NITROETHYL)CYCLOHEXANONES [J].