The Mechanism of 1,4- and 1,6-Cuprate Additions: The First Determination of Activation Parameters

Johannes Canisius; Andreas Gerold; Norbert Krause

doi:10.1002/(SICI)1521-3773(19990601)38:11<1644::AID-ANIE1644>3.0.CO;2-A

The Mechanism of 1,4- and 1,6-Cuprate Additions: The First Determination of Activation Parameters

Angew Chem Int Ed Engl. 1999 Jun 1;38(11):1644-1646. doi: 10.1002/(SICI)1521-3773(19990601)38:11<1644::AID-ANIE1644>3.0.CO;2-A.

Authors

Johannes Canisius¹, Andreas Gerold¹, Norbert Krause¹

Affiliation

¹ Lehrstuhl für Organische Chemie II der Universität, D-44221 Dortmund (Germany), Fax: (+49) 231-755-3884.

Abstract

With a direct kinetic study, activation parameters for the 1,4-cuprate addition to enones (see the Arrhenius plot,▴) and the 1,6-addition to acceptor-substituted enynes (█) were determined for the first time. Both reactions might involve σ copper(III) species which are formed by oxidative addition of the respective substrate to the cuprate.

Keywords: Cuprates; Kinetics; Michael additions; Reaction mechanisms.