cis-2,6-Dimethylpiperidide: a structural mimic for TMP (2,2,6,6-tetramethypiperidide) or DA (diisopropylamide)?

R. Campbell, B. Conway, P. Garcia-Alvarez, A.R. Kennedy, J. Klett, C.T. O'Hara, R.E. Mulvey, G. Robertson, EPSRC (Funder)

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Four novel heterobimetallic ate complexes containing cis-2,6-dimethylpiperidide (cis-DMP) have been prepared and characterised. Two contain one cis-DMP ligand, namely the bisalkyl-amido lithium, and sodium zincates [(TMEDA)·MZn(cis-DMP)(tBu)2] (M = Li for 1, Na for 2). Both 1 and 2 are synthesised by co-complexation of the respective alkali metal amide with di-tert-butylzinc in the presence of a molar equivalent of N,N,N′,N′-tetramethylethylenediamine (TMEDA) in a hydrocarbon medium. The third complex, containing two cis-DMP ligands, is the alkyl-bisamido sodium zincate [(TMEDA)·NaZn(cis-DMP)2(tBu)] 3. Complex 3 is prepared from 2via a disproportionation reaction where the by-product is [(TMEDA)·NaZn(tBu)3]. Another alkyl-diamido sodium zincate, [(TMEDA)·NaZn(DIBA)2(tBu)] 4 is synthesised by utilising diisobutylamine [DIBA(H)]. This reaction emphasises the generality of this disproportionation process. Complex 5 contains three cis-DMP ligands and is a tris-amido sodium magnesiate [(TMEDA)·NaMg(cis-DMP)3]. It is prepared by treating an equimolar mixture of butylsodium and dibutylmagnesium with three and one molar equivalents of cis-DMP(H) and TMEDA respectively, in hydrocarbon solution. By comparison of 1-5 with appropriate complexes from the literature, it has been possible to experimentally determine that the steric bulk of cis-DMP closely resembles that of DA but is considerably less bulky than 2,2,6,6-tetramethylpiperidide (TMP).
Original languageEnglish
Pages (from-to)511-519
Number of pages8
JournalDalton Transactions
Volume39
DOIs
Publication statusPublished - 2010

Keywords

  • heterobimetallic ate complexes
  • cis-DMP
  • diisopropylamide

Fingerprint Dive into the research topics of 'cis-2,6-Dimethylpiperidide: a structural mimic for TMP (2,2,6,6-tetramethypiperidide) or DA (diisopropylamide)?'. Together they form a unique fingerprint.

  • Projects

    Equipment

    x-ray diffractometer

    Alan Kennedy (Manager)

    Pure And Applied Chemistry

    Facility/equipment: Equipment

  • Cite this