Reactivity Studies of Donor-Acceptor Cyclopropanes: Is there a Relation to Structural and Electronic Properties?

Kreft, Alexander; Lücht, Alexander; Grunenberg, Jörg; Jones, Peter G; Werz, Daniel B ORCID

The kinetics of (3+2) cycloaddition reactions of 18 different donor-acceptor cyclopropanes with the same aldehyde were studied by in situ NMR spectroscopy. Increasing the electron density of the donor residue accelerates the reaction by a factor of up to 50 compared to the standard system (donor group=phenyl), whereas electron-withdrawing substituents slow down the reaction by a factor up to 660. This behavior is in agreement with the Hammett substituent parameter σ. The obtained rate constants from the (3+2) cycloadditions correlate well with data from additionally studied (3+n) cycloadditions with a nitrone (n=3) and an isobenzofuran (n=4). A comparison of the kinetic data with the bond lengths in the cyclopropane (obtained by X-ray diffraction and computation), or the 1 H and 13 C NMR shifts, revealed no correlation. However, the computed relaxed force constants of donor-acceptor cyclopropanes proved to be a good indicator for the reactivity of the three-membered ring.

Preview

Cite

Citation style:

Kreft, Alexander / Lücht, Alexander / Grunenberg, Jörg / et al: Reactivity Studies of Donor-Acceptor Cyclopropanes: Is there a Relation to Structural and Electronic Properties?. 2019. Wiley.

Access Statistic

Total:
Downloads:
Abtractviews:
Last 12 Month:
Downloads:
Abtractviews:

show details

Rights

License Holder: This is the peer reviewed version of the following article: Kinetic Studies of Donor–Acceptor Cyclopropanes: The Influence of Structural and Electronic Properties on the Reactivity, which has been published in final form at https://doi.org/10.1002/anie.201812880. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.

Use and reproduction:
All rights reserved

Export