Preparation of Polyfunctional Biaryl Derivatives by Cyclolanthanation of 2-Bromobiaryls and Heterocyclic Analogues Using nBu2 LaCl⋅4 LiCl

Baosheng Wei; Dongchao Zhang; Yi-Hung Chen; Aiwen Lei; Paul Knochel

doi:10.1002/anie.201908046

Preparation of Polyfunctional Biaryl Derivatives by Cyclolanthanation of 2-Bromobiaryls and Heterocyclic Analogues Using nBu₂ LaCl⋅4 LiCl

Angew Chem Int Ed Engl. 2019 Oct 28;58(44):15631-15635. doi: 10.1002/anie.201908046. Epub 2019 Sep 19.

Authors

Baosheng Wei¹, Dongchao Zhang², Yi-Hung Chen², Aiwen Lei², Paul Knochel¹

Affiliations

¹ Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377, München, Germany.
² Institute for Advanced Studies (IAS), College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, 430072, Hubei, P. R. China.

Abstract

Various aryl- and heteroaryl-substituted 2-bromobiaryls are converted to cyclometalated lanthanum intermediates by reaction with nBu₂ LaCl⋅4 LiCl. These resulting lanthanum heterocycles are key intermediates for the facile preparation of functionalized 2,2'-diiodobiaryls, silafluorenes, fluoren-9-ones, phenanthrenes, and their related heterocyclic analogues. X-ray absorption fine structure (XAFS) spectroscopy was used to rationalize the proposed structures of the involved organolanthanum species.

Keywords: XAFS; condensed aromatics; functionalized organometallics; halogen-lanthanum exchange; lanthanides.