Stereochemical Aspects of Enantiopure and Racemic Organolithium Aggregates Li 4 Ar 4 {Ar = C 6 H 4 [CH(Me)NMe 2 ]‐2}
Abstract The compounds ( R )‐ and rac ‐[1‐(dimethylamino)ethyl]benzene, ( R )‐ 1 and rac ‐ 1 , respectively, react quantitatively with t BuLi in a 1:1 molar ratio in pentane to give the corresponding ( R )‐ and rac ‐[Li 4 {C 6 H 4 [CH(Me)NMe 2 ]‐2} 4 ], ( R )‐ 2 and rac ‐ 2 , respectively. The same...
Saved in:
Published in | European journal of organic chemistry Vol. 2004; no. 1; pp. 153 - 159 |
---|---|
Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
01.01.2004
|
Online Access | Get full text |
Cover
Loading…
Summary: | Abstract
The compounds (
R
)‐ and
rac
‐[1‐(dimethylamino)ethyl]benzene, (
R
)‐
1
and
rac
‐
1
, respectively, react quantitatively with
t
BuLi in a 1:1 molar ratio in pentane to give the corresponding (
R
)‐ and
rac
‐[Li
4
{C
6
H
4
[CH(Me)NMe
2
]‐2}
4
], (
R
)‐
2
and
rac
‐
2
, respectively. The same reaction with
n
BuLi afforded a 1:1:1 aggregate of
n
BuLi,
2
, and
1
according to the results of quench experiments with H
2
O and D
2
O. The
1
H,
13
C, and
7
Li NMR spectra, as well as the single‐crystal X‐ray structure, reveal that (
R
)‐
2
has a unique self‐assembled tetranuclear structure of two diastereoisomeric dimeric units both in solution, in non‐coordinating hydrocarbon solvents, and in the solid state. Detailed information about
rac
‐
2
, which, in contrast to the high solubility of (
R
)‐
2
, is essentially insoluble in hydrocarbon solvents, was provided by
13
C CP/MAS NMR spectra. We conclude that
rac
‐
2
is a self‐assembled tetranuclear aggregate comprising a combination of two dimeric units, but in this case they are derived from the (
R
)‐ and (
S
)‐enantiomers, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) |
---|---|
ISSN: | 1434-193X 1099-0690 |
DOI: | 10.1002/ejoc.200300550 |