Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

11-2001

Journal or Book Title

Organometallics

Volume

20

Issue

24

First Page

5171

Last Page

5176

DOI

10.1021/om010513u

Abstract

Iron(II) complexes of meso-tetra-p-tolylporphyrin (TTP), tetramethyldibenzotetraaza[14]annulene (tmtaa), and trans-1,2-bis(salicylidene)cyclohexanediamine (saldach) catalyzed the cyclopropanation of styrene with aryldiazomethanes. When p-tolyldiazomethane was used as the carbene source, trans-cyclopropanes were the major products. Trans/cis ratios of up to 17:1 were obtained. However, using mesityldiazomethane resulted in a reversal of stereoselectivity, giving cis-cyclopropanes as the major product (cis/trans ratios of up to 2.9:1). The stereoselectivity of iron(II) porphyrin-catalyzed cyclopropanation reactions was enhanced by performing the reactions at low temperature or by using bulky porphyrin ligands. Using trimethylsilyldiazomethane as the carbene source, trimethylsilylcyclopropanes were produced in excellent yields with (TTP)Fe. On treatment of (TTP)Fe with diazoreagents, carbene complexes were observed spectroscopically. These complexes transferred their carbene ligand to styrene to produce cyclopropanes stoichiometrically.

Comments

Reprinted (adapted) with permission from Organometallics 20 (2001): 5171, doi:10.1021/om010513u. Copyright 2001 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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