Transition Metal Acetylide Rearrangement and Coupling Induced by Coordinative Unsaturation

Abstract

The reaction of Ar′Fe(μ-Br)2 (Ar′ = C 6H3-2,6-(C6H3-2,6-iPr 2)2) with LiC=CPh afforded the unusual 1,3-butadiene-1,4-diyl Fe(I)-coupled derivative Fe2Ar′C=C(Ph)- C(Ph)=CAr′ (1), whereas the reaction of Ar′Fe(μ-Br) 2 with LiC≡CtBu yielded the monomeric Fe(II) “ate” complex Ar′Fe(C≡CtBu)2Li(THF) 2 (2). Complexes 1 and 2 were characterized by X-ray crystallography, NMR, and UV-vis spectroscopy and magnetic measurements. In 1 the dimeric structure is a result of Ar′ group transfer to the iron-bound carbon of the acetylide ligand and subsequent dimerization via coupling of the phenyl-substituted carbons. The irons are antiferromagnetically coupled, and the iron-iron separation is 2.5559(3) Å. In 2 the high-spin iron atom has distorted trigonal-planar coordination with a THF-complexed lithium ion associated with the Ar′Fe(C≡CtBu)2 anion via interactions with the tBu-substituted alkyne carbons. © 2009 American Chemical Society.

Department(s)

Chemistry

International Standard Serial Number (ISSN)

0276-7333

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2009 American Chemical Society (ACS), All rights reserved.

Publication Date

01 Jan 2009

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