Modulable and Highly Diastereoselective Carbometalations of Cyclopropenes. Issue 4 (12th December 2013)

• Record Type: Journal Article
• Authors: Didier, Dorian; Delaye, Pierre‐Olivier; Simaan, Marwan; Island, Biana; Eppe, Guillaume; Eijsberg, Hendrik; Kleiner, Amir; Knochel, Paul; Marek, Ilan
• Is Part Of: Chemistry. Volume 20:Issue 4(2014)
• Page Start: 1038
• Page End: 1048
• Publication Date: 2013-12-12
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201303569
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The copper‐catalyzed carbomagnesiation reaction of cyclopropenyl esters <bold>1</bold> leads to various substituted cyclopropanes species <bold>3</bold> in good yields with very high diastereoselectivities. The reaction proceeds through a <italic>syn</italic>‐chelated carbomagnesiation reaction and could be extended to various cyclopropenylmethyl ester derivatives <bold>5</bold>. The potential of this approach was illustrated by the preparation of two consecutive all‐carbon quaternary stereocenters. However, the carbometalation reaction needs to be performed at temperature ranging from −35 to −20 °C to avoid subsequent fragmentation reaction into stereodefined β, γ‐nonconjugated unsaturated esters <bold>4</bold>. Alternatively, the carbocupration reaction with organocopper species could also be performed to leads to configurationally stable cyclopropyl copper species <bold>2[Cu]</bold>. Additionally, when the Lewis acid character of the copper center is decreased (i.e., RCuCNLi), the reaction proceed with an <italic>anti</italic>‐selectivity. The diastereodivergent behavior of these organometallic species is of synthetic interest, since both diastereomers <italic>syn</italic>‐<bold>3</bold> and <italic>anti</italic>‐<bold>3</bold> can be obtained, at will, from the same precursor cyclopropenyl esters <bold>1</bold>.</p> </abstract>