Synthesis 2023; 55(06): 892-898
DOI: 10.1055/s-0042-1751386
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Lewis Acid Catalysed Asymmetric One-Carbon Ring-Expansion of Prochiral Cyclobutanones

a   Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10–14, 55128 Mainz, Germany
b   Organisch-Chemisches Institut, Westfälische Wilhelms-Universität, Corrensstrasse 36, 48149 Münster, Germany
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a   Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10–14, 55128 Mainz, Germany
› Author Affiliations
Generous financial support from the Johannes Gutenberg-Universität, the Westfälische Wilhelms-Universität, and the Fonds der Chemischen Industrie (Liebig fellowship to J.M.W. & Liebig-Ph.D. fellowship to M.T.) is acknowledged.


Abstract

Enantioselective methylene insertion into prochiral cyclobutanones is described providing access to chiral β-substituted cyclopentanones as important structural motif in synthesis and natural products. Commercially available trimethylsilyl as well as other silyl diazomethanes act as one-carbon synthon and scandium triflate is found to be a potent Lewis acid catalyst. By using bis(oxazoline) ligands, enantioinduction is achieved for a number of β-substituted cyclopentanones including examples bearing all-carbon quaternary stereocentres.

Supporting Information



Publication History

Received: 27 September 2022

Accepted after revision: 21 October 2022

Article published online:
16 November 2022

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