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Multisite Catalysis: A Mechanistic Study of β-Lactone Synthesis from Epoxides and CO—Insights into a Difficult Case of Homogeneous Catalysis by Ferenc Molnar; Gerrit A. Luinstra; Markus Allmendinger; Bernhard Rieger is a Chemistry article available to read on EtoBox.

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## Abstract Carbonylation of epoxides with a combination of Lewis acids and cobalt carbonyls was studied by both theoretical and experimental methods. Only multisite catalysis opens a low‐energy pathway for __trans__ opening of oxirane rings. This ring‐opening reaction is not easily achieved with a single‐site metal catalyst due to structural and thermodynamic constraints. The overall reaction pathway includes epoxide ring opening, which requires both a Lewis acid and a tetracarbonylcobaltate nucleophile, yielding a cobalt alkyl—alkoxy–Lewis acid moiety. After CO insertion into the CoC~alkyl~ bond, lactone formation results from a nucleophilic attack of the alkoxy Lewis acid entity on the acylium carbon atom. A theoretical study indicates a marked influence of the Lewis acid on both ring‐opening and lactone‐formation steps, but not on carbonylation. Strong Lewis acids induce fast ring opening, but slow lactone formation, and visa versa: a good balance of Lewis acidity would give the fastest catalytic cycle as all steps have low barriers. Experimentally, carbonylation of propylene oxide to __β__‐butyrolactone was monitored by online ATR‐IR techniques with a mixture of tetracarbonyl

Who reads Multisite Catalysis: A Mechanistic Study of β-Lactone Synthesis from Epoxides and CO—Insights into a Difficult Case of Homogeneous Catalysis?

Author

Ferenc Molnar; Gerrit A. Luinstra; Markus Allmendinger; Bernhard Rieger

Publisher

John Wiley and Sons; Wiley (John Wiley & Sons); John Wiley & Sons Ltd.; Wiley (ISSN 0947-6539)

Published

2003

Language

EN

Field

Chemistry (Physical Sciences)