Andrews, Philip C. and Barnett, N.D.R. and Mulvey, Robert and Clegg, W. and O'Neil, P.A. and Barr, Donald and Cowton, Lucy and Dawson, Andrea J. and Wakefield, Basil J. (1996) X-ray crystallographic studies and comparative reactivity studies of a sodium diisopropylamide (NDA) complex and related hindered amides. Journal of Organometallic Chemistry, 518 (1-2). pp. 85-95. ISSN 0022-328XFull text not available in this repository. (Request a copy from the Strathclyde author)
Two related sodium amide complexes derived from secondary amines with bulky organic substituents have been synthesised and crystallographically characterised. Both [(Pr-i)(2)NNa(TMEDA)](2) and [Cy(Pr-i)NNa(TMEDA)](2) adopt dimeric crystal structures with a central, planar (nitrogen-metal)(2) azametallocycle, a now familiar feature in both lithium amide and sodium amide chemistry. TMEDA ligands chelate in their usual bidentate manner making the Na+ cations four-coordinate with a distorted tetrahedral geometry. In the latter complex, the amido substituents are disposed in a trans conformation with respect to the (NNa)(2) ring plane. The deprotonating ability of the former complex has been tested against that of the parent amide [(Pr-i)(2)NNa](infinity) and the lithium congener [(Pr-i)(2)NLi](infinity) (LDA) in a series of simple organic reactions: selective enolate formation from 2-octanone and 2-methylcyclohexanone; synthesis of diphenylacetic acid via diphenylmethane. In general, the performance of the sodium reagents compares favourably with that of the lithium reagent.
|Keywords:||lithium, sodium, amide, crystal structure, lithium diisopropylamide, ladder, solid state, hexamethylphosphoric triamide, enolate formation, ring, Chemistry, Materials Chemistry, Biochemistry, Organic Chemistry, Physical and Theoretical Chemistry, Inorganic Chemistry|
|Subjects:||Science > Chemistry|
|Department:||Faculty of Science > Pure and Applied Chemistry|
|Depositing user:||Pure Administrator|
|Date Deposited:||05 Mar 2012 16:44|
|Last modified:||09 Dec 2016 10:29|