Indyllithium and the Indyl Anion [InL]- : Heavy Analogues of N-Heterocyclic Carbenes

Ryan J Schwamm; Mathew D Anker; Matthias Lein; Martyn P Coles; Christopher M Fitchett

doi:10.1002/anie.201802444

Indyllithium and the Indyl Anion [InL]^- : Heavy Analogues of N-Heterocyclic Carbenes

Angew Chem Int Ed Engl. 2018 May 14;57(20):5885-5887. doi: 10.1002/anie.201802444. Epub 2018 Apr 14.

Authors

Ryan J Schwamm¹, Mathew D Anker¹, Matthias Lein¹, Martyn P Coles¹, Christopher M Fitchett²

Affiliations

¹ School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6012, New Zealand.
² Department of Chemistry, University of Canterbury, Private Bag 4800, Christchurch, 8041, New Zealand.

PMID: 29575533
DOI: 10.1002/anie.201802444

Abstract

Reduction of the indate complex In(NON^Ar )(μ-Cl)₂ Li(OEt₂ )₂ (NON^Ar =[O(SiMe₂ NAr)₂ ]^2- ; Ar=2,6-iPr₂ C₆ H₃ ) with sodium generates the In^II diindane species [In(NON^Ar )]₂ . Further reduction with a mixture of potassium and [2.2.2]crypt affords the In^I N-heterocyclic indyl anion [In(NON^Ar )]^- , which crystallizes with a non-contacted [K([2.2.2]crypt)]⁺ cation. The indyl anion can also be isolated as the indyllithium compound In(NON^Ar )(Li{THF}₃ ), which contains an In-Li bond. Density functional theory calculations show that the HOMO of the indyl anion is a metal-centred lone pair, and preliminary reactivity studies confirm its nucleophilic behaviour.

Keywords: N-heterocyclic carbenes; diindanes; indium; indyl anions; main-group chemistry.