Formation of a bridging planar trimethylenemethane dianion from a neopentyl precursor via sequential beta-alkyl elimination and C-H activation

William J Evans; Jeremy M Perotti; Joseph W Ziller

doi:10.1021/ja044529y

Formation of a bridging planar trimethylenemethane dianion from a neopentyl precursor via sequential beta-alkyl elimination and C-H activation

J Am Chem Soc. 2005 Feb 2;127(4):1068-9. doi: 10.1021/ja044529y.

Authors

William J Evans¹, Jeremy M Perotti, Joseph W Ziller

Affiliation

¹ Department of Chemistry, University of California-Irvine, Irvine, California 92697-2025, USA. [email protected]

PMID: 15669823
DOI: 10.1021/ja044529y

Abstract

The reaction of neopentyllithium, Me3CCH2Li, with [(C5Me5)2Sm][(mu-Ph)2BPh2], 1, was investigated as a route to the unsolvated alkyl, [(C5Me5)2Sm(CH2CMe3)]x, and found to generate the first f element trimethylenemethane dianion complex, [(C5Me5)2Sm]2[mu-eta3:eta3-C(CH2)3], 2. Formation of the [C4H6]2- trimethylenemethane ligand from the [C5H11]1- neopentyl precursor can be explained by a combination of a beta-methyl elimination reaction to form isobutene and [(C5Me5)2SmMe]3, 3, with subsequent C-H activation reactions. This sequence has been modeled in several ways, including the synthesis of 2 from reactions of 3 with CH2=CMe2 and 3 with the 2-methylallyl complex, (C5Me5)2Sm[CH2C(Me)CH2], 4.