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Direct Synthesis and Separation of Asymmetric Phosphane-Manganese Complexes.

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Genera/ procedure:
The linear depsipeptide is dissolved together with 2 equiv.
of o-phenylene chlorophosphite in diethyl phosphite and
heated under nitrogen at a bath temperature of 100-C.
For cyclization a solution of 3 equiv. of triethylamine
dissolved in 10 ml of diethyl phosphite is added dropwise
to the reaction mixture with vigorous stirring. The reaction
mixture is stirred for 30 min at the above temperature,
then cooled and evaporated under oil-pump vacuum. The
oily residue is dissolved in methylene dichloride, extracted
with 10% NaHC03 solution, and then with water. After
evaporation, the residue is chromatographed on Sephadex
LH 20 (eluant : methanol); the oligomeric cyclodepsipeptides are obtained from the fractionated eluates.
Received: September 28, 1973 [Z 936 IE]
German version: Angew. Chem. 8S, 1103 (1973)
[CH,C,H,Mn(CO),NO]+PF;
(KBr: vco 2150 and 2100
cm- ; vNo 1860 cm- I). There results a diastereoisomeric
pair ( 2 a ) / ( 2 b )which can be resolved owing to solubility
differences. The optical purity of the fractions obtained
in the individual separation steps can be established by
NMR spectroscopy since the two diastereoisomers differ
in their ‘H-NMR spectra.
( 2 a ) and ( 2 b ) display identical IR spectra (KBr): vco
2060 cm-’; vNo 1795 cm-’. Their specific rotations and
H-NMR parameters are listed in Table 1.
Like
the
enantiomers
(+)and
(-)[C,H,Mn(CO)(NO)P(C,H,),] +PF;, the optically active
diastereoisomers ( 2 a ) and ( 2b ) are configurationally
stable”’. The rotations of their solutions remain constant
for a long period in the absence of light and oxygen.
Preparation of
( S ) - ( ) -(C, H,)
Direct Synthesis and Separation of Asymmetric
Phosphane-Manganese Complexes“I
+
By Hmri B ~ L M Jand
I C ~W~lfytrrzy
~
rum bold^*]
The following optically active compounds have so far found
application in the preparation of diastereoisomeric organometallic compounds of the transition elements : the
mentholate
ion
OC 10Hly12’31; the
isocyanide
C~NCH(CH,)(C,H5)[3J;the
amine H2NCH(CH,)(C,H,)141;
and the chelate Schiff bases of 2-pyridinaldehyde and of the
2-pyrrolaldehyde anion with a-phenylethylamine131.Since
phosphanes are excellent ligands in transition metal complexes of lower oxidation states, optically active phosphanes
should be universally applicable for the direct introduction
of diastereoisomerism.
J” ( C H , ) C H ( C H , )
(C, H , ) ( 1 )
(S)-(-)-a-Phenylethylamine is at first formylated with
HCOOC,H, and then reduced with LiAIH, to give
(S)-(-)-(CH,)NHCH(CH3)(C,H,)[S1: [ a ] g= - 82” (neat,
d Z 5=0.92 gcm-3). A solution of freshly distilled
diphenylchlorophosphane (1 8.4 g, 0.08 mol) in ether (50 ml)
is added dropwise to this amine (30g, 0.22mol) in diethyl
ether (200ml) at &5‘C over 2 h with exclusion of air
and moisture. The reaction mixture is refluxed for 4h,
the solvent drawn off (after filtration to remove the amine
hydrochloride), and the residue extracted with three 30-ml
portions of pentane. After concentration of the pentane
extract to 20 ml, residual hydrochloride is removed first at
- 20°C and the solvent and excess amine are then removed
\
+
-C O
PFF
A
The reaction of the secondary amine (S)-(-)(CH3)HNCH(CH3)(C6H5)[’1[obtainable from (S)-(-)H2NCH(CH,)(C,H,)]
with diphenylchlorophosphane
does not involve the center of asymmetry; the conveniently
accessible potential ligand ( 1 ) is therefore optically pure.
Reaction of [C5H5Mn(C0)2NO]+PF; with P(C6H5)3
affords
the
monosubstitution
product
[CSHSM~(CO)(NO)P(C~HS)~]+PF;[~’.
Correspondingly,
( 1 ) displaces one of the enantiotopic CO groups in
[*] Prof. Dr. H. Brunner and Dip1.-Chem. W. Rambold
Fachbereich Chemie der Universitat
84 Regensburg, Universitatsstrasse 31 (Germany)
Angrw. Chrm. intrmat. Edit. J Vol. 12 ( 1 9 7 3 ) /
NO.12
4
in a high vacuum. Yield of ( I ) 93%; mass spectrum:
molecular ion m/e 319, rel. int. 12% (based on m/e 262,
rel. int. 10%).
Preparation of the diastereoisomeric complex salts ( 2 a )
and ( 2 b )
[CH3C5H4Mn(CO),(NO)]+PF; (1.57 g, 4.3 mmol) in acetone (50 ml) is united with ( I ) (1.38g, 4.3 mmol) in acetone
(20 ml) at room temperature with exclusion of air (vigorous
liberation of CO). After 4 h the sofution is filtered and
the solvent drawn off. The residue is chromatographed
in CHzClz(5ml) over Sephadex LH 20/CHzC12.Removal
of the CH2Cl2leaves an oily residue which can be converted
into powder form by prolonged stirring in pentane. Only
1013
Table I . Specific rotations and 'H-NMR data of (I), (2u), and (26).
-
specific
rotations
(1)
(2 a )
( 2 bl
(ca. 15 mg/ml, CH,CI,)
(CQ.
4 mg/ml. CH'C1,;
100% opt. pure)
+ 256
+ 307
495
-1470
(en. 4 mg!ml, CH,Cl,;
[a]:i9= +
57
[a]::9=
64
[a]::,=+
72
[a]::,=
+I56
[a]::,=
+340
+
+
+
I
(c,cI,; ~ 6 0 )
[a]
assignment
C-CH,
'8.47(3); 8 [b]
'7.82(3); 3 [d]
N-CH,
"S.40(1); 8 [b]
C-H
C-C,H,
m2.77(15 ) ;
P(C,H,),
'H-NMR
70% opt. pure)
- 162
- 208
-315
806
{
([D,]acetone; XL100)
[a]
assignment
'8.36(3); 7 [b]
C-CH,
"'7.90(3); [c]
CSH4-CH3
'7.46(3);9 [d]
N-CH,
mS.17(1);
C-H
"'5.01
"'4.70 (4);
C5H4
"'4.37
C-C,H,
'2.64( 5 ) ;
"2.31(10);
P(C,H,),
)
([D,] acetone; XL 100)
[a]
assignment
28.40(3);7[b]
C-CH,
"'7.90(3); [c]
CSH,-CH3
'7.48(3); 9 [d]
N-CH,
"5.17(1);
C-H
:';](4);
m4.37
'2.6q5);
m2.31(10);
C5H4
C-C,H,
P(C,HJz
[a] r-values (rel. int.) TMS internal standard; coupllng constants [Hz] - multiplicities: superscripts preceding the
r-values.
[b] J C H - C H )[cl
. Beneath acetone signal. [d] JPNCH?
part of the yellow salt dissolves in a 30-ml portion of
methanol. The more sparingly soluble fraction is dissolved
in acetone and cooled to -20°C with addition of ether
(until crystallization starts). This separating operation is
repeated with the resulting recrystallized product to give
the less soluble (+)-rotatory diastereoisomer ( 2 a ) in optically pure ('H-NMR) form; yield CU. 10%; dec. 145°C.
The methanolic solution obtained in the first fractionation
is evaporated down to a volume of 3ml and allowed
to crystallize at -20°C. After repetition of this separating
step the residual solution contains the more readily soluble
(-)-rotatory diastereoisomer ( 2 b), contaminated, according to the 'H-NMR spectrum, with about 15% of ( 2 a ) ;
yield ca. 15%,dec. 130 C.
K L. .L .L I \ C ~ l ~ l ! 26. IY72
[Z922 IF]
German \erston: Angew. Chem. 85. 1 1 18 (1973)
~- ...
with our studies on nucleophilic aminoalkylation with
rnetalated nitro~amines[~'
such as ( I ) we have sought
other "activating" groups and checked the possibility
of preparing the lithium derivative (2) from dimethylthi~formamide'~].
Much to our surprise a yellow solution
of dimethylthiocarbamoyllithium ( 3 ) [51 is formed in
almost quantitative yield (according to deuterolysis) on
adding thioformamide to the T H F solution of lithium
diisopropylamide at - 100°C. Addition of benzophenone
leads to the adduct ( 4 a ) in 85% yield (see experimental
section and Table 1).
HsC,
,CHpLi@
H3C,
NI
,CHpLi@
NI
0
H
F*S
-
[ I ] Optically Active Transition Metal Complexes, Part 23. Thrs work
was supported by the Deutsche Forschungsgemeinschaft and the Fonds
der Chemischen 1ndustrie.-Part 22: H . Brunner and W A . Hrrrmnnn.
2. Naturforsch. in press.
~F.
C iic~ii.\ i . 174 I 1Y71 I. Aiigcw. C hcm Inlcrnat.
[2] ti B F I $ I I I I\iisc\\.
Edit. 10. 24Y IIY711
[3] H . Brunner and W A. Herrmann, Z. Naturforsch. in press; and
prci 1oi1\ C ' O ~ ~ ~ I ~ ~ L I I ~ I C ~ I I111
O I ~[hi\
\
scrics.
[4] A. Dul-rson and D. L. Regrr, J. Amer. Chem. SOC.Y4, 9231 (1972).
[5] 0. Crrcinku, E . Kroupoca, and 0. Brloaskg, Z. Chem. 8, 24 (1968).
[6] H . Brunnrr and H . - D . Sckmdler, J. Organometal. Cbem. 19, 135
(1969): R . B. King and A. Efraty, Inorg. Chem. 8, 2374 (1969); 71 A.
James and J . A. McCleaerty, J. Chem. SOC.A 1970, 850.
[ 7 ] H. Brunner and H . - D . Schindlrr, J. Organometal. Chem. 24, C 7
(1970).
Nucleophilic Thioacylation with
Dimethylthiocarbamoyllithium[**I
Solutions
of
By Dieter Enders and Dieter Seeback[*]
Methods for nucleophilic acylation[ll have recently found
increasing application in organic synthesisf21.In connection
['I
DipLChem D. Enders and Prof. Dr. D. Seebach
lnstitut fur Organische Chemie. Fachbereich Chemie der Universitat
63 Giessen, Ludwigstr. 21 (Germany)
[**] This work was supported by the Deutsche Forschungsgemeinschaft
and by the Fonds der Chemischen Industrie. D. E. thanks the Studienstiflung des Deutschen Volkes for a stipendium.
1014
If the reaction mixture is allowed to warm to -78°C
within 15 min after the metalation and then stirred for
a further 15 min period at this temperature, only 20%
of ( 4 a ) is obtained. As shown in Table 1 other aliphatic
and aromatic aldehydes and ketones can be converted
into a-hydroxythioamides in good yields. Reaction with
methyl iodide leads to ( 4 h ) , and with methyl benzoate to
(49) (Table 1).
Experimental:
N,N-Dimethyl-2-hydroxy-2,2-diphenylthioacetamide
(4a )
To a stirred solution of lithium diisopropylamide (10mmol)
in THF/hexane (5:l) is added a solution of N,N-dimethylthioformamide (0.88 g, 10 mmol) in THF (2 ml) over 1 min
at - 100°C. After 3min the resultant yellow solution is
treated with a solution of benzophenone (1.82 g, l0mmol)
in T H F (7ml). The bath temperature is allowed to rise
to -70°C over a period of 1 h and the reaction mixture
then neutralized with glacial acetic acid (0.6ml). Work-up
Aiigew. Chem. iiirernat. Edit.
/ Vol. 12 (1973) No. I 2
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asymmetric, separating, synthesis, phosphane, direct, complexes, manganese
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