Epoxidation and Hydroxylation with Peracids

[Rhodium]

Epoxidation and Hydroxylation of Alkenes with Organic Peracids
Daniel Swern

Organic Reactions, Vol. 7, Ch. 7, pp 378-433 (1953)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/peracid.oxidation.or7.pdf)

Contents

Introduction
Scope
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Epoxidation
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Hydroxylation
Stereochemistry and Mechanism
Selection of Experimental Conditions
Experimental Procedures
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Analysis of Peracids
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Preparation of Peracids
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Perbenzoic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Monoperphtalic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Peracetic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_oxgw.gif" title="View this image">Performic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Epoxidation with Perbenzoic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Epoxidation with Monoperphtalic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Hydroxylation with Hydrogen Peroxide-Acetic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Hydroxylation with Hydrogen Peroxide-Formic Acid
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">Hydroxylation with Performic Acid
Table I: Alkenes Oxidized with Organic Peracids
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">A. Hydrocarbons
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">B. Steroids
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">C. Acids
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">D. Alcohols
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">E. Esters
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">F. Aldehydes and Ketones
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">G. Ethers
https://www.thevespiary.org/rhodium/Rhodium/hive/hiveboard/picproxie_docs/000481655-file_fdlo.gif" title="View this image">H. Miscellaneous
References

[Rhodium]

Mechanism of Acid-Catalyzed Epoxidation of Alkenes with Peroxy Acids
Robert D. Bach, Carlo Canepa, Julia E. Winter and Paul E. Blanchette

J. Org. Chem. 62, 5191-5197 (1997)

(https://www.thevespiary.org/rhodium/Rhodium/pdf/peracid.epoxidation.mechanism.pdf)

Abstract
A 6.8 fold increase in the rate of epoxidation of (Z)-cyclooctene with m-chloroperbenzoic acid is observed upon addition of the catalyst trifluoroacetic acid. Kinetic and theoretical studies suggest that this increase in rate is due to complexation of the peroxy acid with the undissociated acid catalyst (HA) rather then protonation of the peroxy acid. The transition structure for oxidation of ethylene with protonated peroxyformic acid exhibits a spiro orientation of the electrophilic oxygen at the QCISD/6-31G(d) level and the complexed peroxy acid (HCO₃H·HA) transition state is also essentially spiro at the ab initio and density functional levels. At the B3LYP/6-311G(d,p) level the protonated transition structure exhibits a more planar approach where the O₃-H₉ of the peroxy acid lies in the plane of the ?-system of ethylene, and the barrier for formation of protonated oxirane is only 4.4 kcal·mol^-1. Epoxidation with neutral and complexed peroxyformic acid also involves a symmetrical spiro orientation affording an epoxide, and the barriers for formation of oxirane at the same level are 14.9 kcal·mol^-1 and 11.5 kcal·mol^-1, respectively. The free energy of activation for the epoxidation of ethylene by peroxyformic acid is lowered by about 3 kcal·mol^-1 upon complexation with the catalyst.