Ruthenium- and Rhodium-catalyzed Carbenoid Reactions of Diazoesters in Hexaalkylguanidinium-based Ionic Liquids

被引：5

作者：

Large, Torsten ^{[1
]}

Mueller, Tobias ^{[1
]}

Kunkel, Helene ^{[1
]}

Buck, Stefan ^{[1
]}

Maas, Gerhard ^{[1
]}

机构：

[1] Univ Ulm, Inst Organ Chem 1, D-89081 Ulm, Germany

来源：

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B-A JOURNAL OF CHEMICAL SCIENCES | 2012年 / 67卷 / 04期

关键词：

Diazoacetates; Cyclopropanation; C-H Insertion; Ionic Liquids; Rhodium; Ruthenium; C-H INSERTION; CYCLOPROPANATION REACTIONS; DIAZO-COMPOUNDS; EFFICIENT; SYSTEM; 2-NITROCYCLOHEXANONE; IMMOBILIZATION; COMPLEXES; ACETATE; ALKENES;

D O I：

10.5560/ZNB.2012.67b0347

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

Hexaalkylguanidinium-based room-temperature ionic liquids were investigated as solvents for the cyclopropanation of styrene with diazoacetates catalyzed by Rh-2(OAc)(4) or [Ru-2(mu-OAc)(2)(CO)(4)](n). While the yields of the formed cyclopropanes are much lower compared to the reactions performed in dichloromethane, the diastereomeric ratio is not significantly affected by the change of the reaction medium. Immobilization of the catalysts is only partially successful. In contrast to this intermolecular reaction, the Ru-catalyzed formation of a beta-lactam by an intramolecular carbenoid C-H insertion of an alpha-methoxycarbonyl-alpha-diazoacetamide occurs in high yield, similar to the Rh-2(OAc)(4)-catalyzed reaction. The cis -> trans isomerization of the resulting 1-terf-butyl-3-methoxycarbonyl-4-phenylazetidin-2-one is accelerated in the ionic liquid N,N-dibutyl-N',N'-diethyl-N '',N ''-dihexylguanidinium triflate.

引用

页码：347 / 353

页数：7

共 43 条

[1] TRANSITION-METAL-CATALYZED REACTIONS OF DIAZO-COMPOUNDS .1. CYCLOPROPANATION OF DOUBLE-BONDS [J].