𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Bis(oxazoline)·copper(I)-catalyzed enantioselective cyclopropanation of cinnamate esters with diazomethane

✍ Scribed by André B. Charette; Marc K. Janes; Hélène Lebel

Publisher
Elsevier Science
Year
2003
Tongue
English
Weight
252 KB
Volume
14
Category
Article
ISSN
0957-4166

No coin nor oath required. For personal study only.

✦ Synopsis

Chiral bis(oxazoline)-copper(I) complexes were found to be effective catalysts for the enantioselective cyclopropanation reaction of trans-cinnamate esters exploiting an argon flow mediated diazomethane addition method. After optimization of the catalyst structure, good yields and enantiomeric excesses were obtained with electron-poor methyl cinnamate derivatives. Sterically demanding esters gave lower yields and enantioselectivities. The correlation between the product enantiopurities and the s + values of the aromatic para-substituents was shown to be linear in a Hammet-type plot.

📜 SIMILAR VOLUMES

C1-Symmetric Versus C2-Symmetric Ligands
C1-Symmetric Versus C2-Symmetric Ligands in Enantioselective Copper–Bis(oxazoline)-Catalyzed Cyclopropanation Reactions
✍ José M Fraile; José I. García; Anja Gissibl; José A. Mayoral; Elísabet Pires; Ol 📂 Article 📅 2007 🏛 John Wiley and Sons 🌐 English ⚖ 496 KB 👁 1 views

## Abstract A thorough experimental and theoretical study of the enantioselective cyclopropanation of alkenes catalyzed by chiral bis(oxazoline)– and azabis(oxazoline)–copper complexes, which comprise a new family of ligands that lack __C__~2~ symmetry, has been conducted. Surprisingly high enantio

Enantioselective Cyclopropanation of Sty
Enantioselective Cyclopropanation of Styrene Catalysed by Copper(I) Complexes with Chiral Oxazolines
✍ Giorgio Chelucci; Maria G. Sanna; Serafino Gladiali 📂 Article 📅 2000 🏛 Elsevier Science 🌐 French ⚖ 140 KB

AbstractÐA large set of copper complexes, prepared in situ from copper(I)-tri¯ate and a variety enantiopure oxazoline ligands, was assessed as chiral catalysts in the enantioselective cyclopropanation of styrene by ethyl diazoacetate. Enantioselectivities up to 60% and up to 52%, respectively, for t