Campus Units

Chemistry

Document Type

Article

Publication Version

Published Version

Publication Date

9-1995

Journal or Book Title

Journal of the American Chemical Society

Volume

117

Issue

36

First Page

9194

Last Page

9199

DOI

10.1021/ja00141a011

Abstract

Iron porphryin complexes are active catalysts for the cyclopropanation of alkenes by ethyl diazoacetate. Fe(TIP) (TIP = meso-tetra-p-tolylporphyrin), an isolated iron(II) porphyrin complex, can be used as the catalyst, or the iron(III) complexes of several porphyrins can be reduced in situ. The reactions produce synthetically useful excesses of the trans cyclopropyl ester products. This stereoselectivity exhibits a modest solvent dependence, with donor solvents giving higher ratios of the trans cyclopropane products. The diastereoselectivity exhibits only a modest dependence on the steric bulk of the porphyrin. The reactions are selective for 1-alkenes and 1, 1-disubstituted alkenes. Conjugated substrates and enol ethers react more rapidly than simple aliphatic alkenes. A mechanistic model for the iron-mediated reactions is proposed which is consistent with the data presented herein.

Comments

Reprinted (adapted) with permission from Journal of the American Chemical Society 117 (1995): 9194, doi:10.1021/ja00141a011. Copyright 1995 American Chemical Society.

Copyright Owner

American Chemical Society

Language

en

File Format

application/pdf

Included in

Chemistry Commons

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