Abstract
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.
| Language | English |
|---|---|
| Pages | 85-95 |
| Number of pages | 11 |
| Journal | Journal of Organometallic Chemistry |
| Volume | 518 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 12 Jul 1996 |
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Keywords
- lithium
- sodium
- amide
- crystal structure
- lithium diisopropylamide
- ladder
- solid state
- hexamethylphosphoric triamide
- enolate formation
- ring
Cite this
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X-ray crystallographic studies and comparative reactivity studies of a sodium diisopropylamide (NDA) complex and related hindered amides. / Andrews, Philip C.; Barnett, N.D.R.; Mulvey, Robert; Clegg, W.; O'Neil, P.A.; Barr, Donald; Cowton, Lucy; Dawson, Andrea J.; Wakefield, Basil J.
In: Journal of Organometallic Chemistry, Vol. 518, No. 1-2, 12.07.1996, p. 85-95.Research output: Contribution to journal › Article
TY - JOUR
T1 - X-ray crystallographic studies and comparative reactivity studies of a sodium diisopropylamide (NDA) complex and related hindered amides
AU - Andrews, Philip C.
AU - Barnett, N.D.R.
AU - Mulvey, Robert
AU - Clegg, W.
AU - O'Neil, P.A.
AU - Barr, Donald
AU - Cowton, Lucy
AU - Dawson, Andrea J.
AU - Wakefield, Basil J.
PY - 1996/7/12
Y1 - 1996/7/12
N2 - 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.
AB - 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.
KW - lithium
KW - sodium
KW - amide
KW - crystal structure
KW - lithium diisopropylamide
KW - ladder
KW - solid state
KW - hexamethylphosphoric triamide
KW - enolate formation
KW - ring
U2 - 10.1016/0022-328X(96)06203-1
DO - 10.1016/0022-328X(96)06203-1
M3 - Article
VL - 518
SP - 85
EP - 95
JO - Journal of Organometallic Chemistry
T2 - Journal of Organometallic Chemistry
JF - Journal of Organometallic Chemistry
SN - 0022-328X
IS - 1-2
ER -