KINETICALLY ENHANCED METALATION - HOW SUBSTITUENTS DIRECT ORTHO LITHIATION

van Eikema Hommes N, Schleyer P (1992)

Publication Status: Published

Publication Type: Journal article

Publication year: 1992

Journal

Angewandte Chemie International Edition Wiley

Publisher: Wiley-VCH Verlag

Book Volume: 31

Pages Range: 755-758

Journal Issue: 6

Abstract

Not the complexation of the ground state but rather of the transition state explains the directing and activating effect of electronegative ortho substituents in the lithiation of aromatic compounds. Ab initio calculations show that the ground state of a C6H5F-LiH complex for para metalation (complexation by the benzene ring) is energetically more favorable than that for ortho metalation (complexation by F), by -12.8 vs. -12.4 kcal mol-1. In the transition state, however, the tables are turned; the respective activation barriers are +17.9 and +6.5 kcal mol-1. This is in accord with the experimental findings that only ortho-fluorolithiobenzene is formed.

Authors with CRIS profile

Nicolaas van Eikema Hommes Computer-Chemie-Centrum Paul Schleyer Naturwissenschaftliche Fakultät

How to cite

APA:

van Eikema Hommes, N., & Schleyer, P. (1992). KINETICALLY ENHANCED METALATION - HOW SUBSTITUENTS DIRECT ORTHO LITHIATION. Angewandte Chemie International Edition, 31(6), 755-758.

MLA:

van Eikema Hommes, Nico, and Paul Schleyer. "KINETICALLY ENHANCED METALATION - HOW SUBSTITUENTS DIRECT ORTHO LITHIATION." Angewandte Chemie International Edition 31.6 (1992): 755-758.

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