Synthesis of Densely Substituted Conjugated Dienes by Transition-Metal-Free Reductive Coupling of Allenylboronic Acids and Tosylhydrazones

Dong Wang; Martin J M de Wit; Kálmán J Szabó

doi:10.1021/acs.joc.8b01104

Synthesis of Densely Substituted Conjugated Dienes by Transition-Metal-Free Reductive Coupling of Allenylboronic Acids and Tosylhydrazones

J Org Chem. 2018 Aug 3;83(15):8786-8792. doi: 10.1021/acs.joc.8b01104. Epub 2018 Jun 7.

Authors

Dong Wang¹, Martin J M de Wit¹, Kálmán J Szabó¹

Affiliation

¹ Department of Organic Chemistry, Arrhenius Laboratory , Stockholm University , SE-10691 Stockholm , Sweden.

PMID: 29792434
DOI: 10.1021/acs.joc.8b01104

Abstract

Tosylhydrazones and allenylboronic acids underwent a transition-metal-free reductive coupling reaction. This process is suitable for synthesis of tetra- and pentasubstituted conjugated dienes. The corresponding allenyl-Bpin substrate showed a very poor reactivity. The reaction is suggested to involve coupling of the in situ formed diazo compound and allenylboronic acid. The intermediate formed in this coupling undergoes allenyl migration followed by protodeboronation to furnish a conjugated diene as major product.

Publication types

Research Support, Non-U.S. Gov't