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Dilithio(phenylsulfonyl)trimethylsilylmethane Synthesis 13C1H-NMR Characterization and Lithium-Titanium Exchange.

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Table I . 'H- and " C - N M R data 01 I . 2. and 3
Dilithio(phenylsu1fonyl)trimethylsilylmethane :
Synthesis, I3C/ 'H-NMR Characterization,
and Lithium-Titanium Exchange**
By Jiirgen Voiihardt, Hans-Joachim Gais,* and
Karl L. Lukas
Dilithioalkyl sulfones of the type Li2[C(R')S02R2]are,
as sulfonyl derivatives of n,n-dilithioalkanes,['] of particular interest, on the one hand because of their structure in
solution and in the crystalline state-whereby aggregation,
number of Li atoms bound to the C atom, and its coordination geometry are of paramount importancel2l-and, on
the other, because of their synthetic potential.[31The dilithiation of alkyl(ary1) sulfones with n-butyllithium (nBuLi) has already been repeatedly described,l4' but a direct
spectroscopic proof for the formation of the dilithio derivatives has not, as yet, been reported; the formation of
a,a-disubstituted alkyl sulfones during the deuteration and
alkylation is, according to our findings with a,o- and a,adilithiated ally1 phenyl s ~ l f o n e s , inconclusive.
We have
now been able to synthesize the title compound 3 , the first
crystalline dilithioalkyl sulfone that is soluble in inert solvents. We have also characterized 3 by I3C- and 'H-NMR
spectroscopy, and been able to convert it by lithium-titanium exchange into a novel organotitanium compound suitable for carbonyl ~lefination.'~]
Lithiation of the trimethylsilyl sulfone lC5]
with one
equivalent of nBuLi in tetrahydrofuran (THF) at -70°C
leads quantitatively to the readily soluble lithioalkyl sulfone 2I6l (Scheme l), whose 'H- and I3C-NMR spectra
characteristically differ from those of 1 (Table 1). Proof of
the structure of 2 is provided, inter aha, by the upfield
shift of AS= 1.65 of the 'H-NMR signal of H-7 and that of
A 6 = 14.7 of the I3C-NMR signal of C-7;17]remarkably, the
"C-NMR signal of C-1 is shifted downfield by A & = 10.9.
Further direct lithiation of 2 to the dilithioalkyl sulfone
3 was achieved smoothly with one equivalent of nBuLi in
T H F ( -7OoC+O0C) without prior o-metalation of the
phenyl ring and subsequent t r a n s m e t a I a t i ~ n [ ~(Scheme
1). On cooling the solution, 3 precipitates as pale yellow
crystals of the composition 3(thQ2. It is, e.g., readily soluble in THF, and stable under argon at 25°C. The I3CNMR signal o f C-7 at 6=50.5 (Table 1) is broadened because of dynamic processes[91and the 7Li-'3C coupling;""'
interestingly, it is shifted by A 6 = 16.7 downfield compared
to that of 2. The observed change in the "C chemical shift
on going from the H2- via the H,Li- to the Li2-compound is
found 'qualitatively' in the series methane, lithiomethane,
dilithiomethane.""] Comparison of the I3C- and 'H-NMR
[*] Priv.-Doz. Dr. H.-J. Gais, Dipl.-Ing. J . Vollhardt. Dr. K. L. Lukas
lnstitut fur Organische Chemie und Biochemie
der Technischen Hochschule
Petersenstrasse 22, D-6100 Darmstadt (FRG)
['I Present address: Chemische Werke Hiils AG
Abteilung Biotechnologie
D-4690 Herne (FRG)
This work was supported by the Deutsche Forschungsgemeinschaft and
the Fonds der Chemischen Industrie.
Verlagsgeselhchaft m b H , 0-6940 Weinheim, 1985
' H - N M R [d]
7.85-7.92 (m)
7.94-8.02 (m)
7.70-8.00 (mj
7.48-7.62 (m)
7.18-7.28 (mj
7.00-7.30 (m)
"C-NMR [b]
C- I
145.4 (5)
156.3 (s)
157.5 (s)
129.8, 127.5 (d)
128.0, 126.1 (d)
127.7, 126.3 (d)
133.4 (d)
128.5 (d)
127.6 (d)
2.85 (sj
1.20 (s)
0.22 (s)
-0.05 (s)
-0.30 (s)
48.5 (tj
33.8 (dj
50.5 (bs)
-0.3 (qj
2.8 (4)
4.8 (qj
[a] 300-MHz N M R spectrum in [D,]THF at ~ 2 5 ° Cwith [H,D]THF as internal standard, 6 values. [b] 75.47-MHz N M R spectra in [D8]THF at ~ 3 5 ° C
with [D,]THF as internal standard, 6 values.
spectra of 1 , 2, and 3 also reveals an increasing downfield
shift of the I3C-NMR signal and an increasing upfield shift
of the 'H-NMR signal of the trimethylsilyl group (Table
1). The crystallinity and solubility of 3 should facilitate
further investigations of its structure in the crystal and in
solution, e.g. by low-temperature I3C- and 6Li-NMR spectroscopy"', "I on [6Li2/7-'3C]-3.
Deuteration of 3 with DCl/D,O/THF ( - 30°C) affords
the D2-compound 4a in 95% yield ( 2 9 8 % deuteration),
while alkylation with methyl iodide (THF, -7O'C) leads
to formation of 2-phenylsulfonyl-2-trimethylsilylpropane,
4b (86%), and cycloalkylation with 1,4-dibromobutane
(THF, O O C ) to formation of the cyclopentyl sulfone 4c
(81%) (Scheme 2); 4c is desilyrated with nBu,NF in T H F
to cyclopentylphenyl sulfone (98%). Peterson olefination
of 3 with benzaldehyde (-70°C-0°C) and reaction with
DCI/D20/THF furnishes the styryl sulfone 5a, deuterated
in the 1-position (55%, 95% deuteration); the trimethylsilyl
styryl sulfone 5 b is formed as byproduct (4%, Scheme 2).
4a , R1 = R2 = D
4b, R' = R2 = M e
5a, R = D
5b, R = SiMe,
412, R', R2 = + C H 2 j 4
Schcine 2
The lithium-metal exchange of 3 with halides of the
early transition metals opens u p an entry to novel functionalized organometal compounds."] Thus, 3 can be titanated with one equivalent of diisopropoxytitanium dichloride in T H F (-90°C- -35°C); the organotitanium compound thus formed has hitherto only been generated as a
deep-red THF-solution. In the titanation of (7- I3C]-3, the
Li-Ti exchange manifests itself "C-NMR spectroscopically in the disappearance of the singlet of c - 7 at 6 = 50.5 ;
a new singlet appears at 6 = 173(!).
The titanium species undergoes no further reaction with
methyl iodide.I3l On the other hand, on reaction with benzaldehyde in T H F at -35"C, the product expected to be
05711-083~/85/0808-0696$ 02 50/0
Angew. Chem. I n r . Ed. Engl. 24 (1985J No. 8
formed in a carbonylolefination, the trimethylsilylated styryl sulfone 5b"'' is obtained in 85% yield ( E : 2 = 2 : 1).
However, the spectroscopic and chemical findings are still
inadequate for differentiation between the lithium-titanium compound 6, the alkylidenetitanium compound 7,
and the dimer 8 (Scheme 3).
[C1( i PrO)2TiC( SiMe,)SO,Ph]Li
Synthesis and Structure of the
[Ni38Pt6(C0)48H6-nnJn(n = 5, 4) Ions:
Ni-Pt Clusters as Models for "Cherry" Crystallites
By Alessandro Ceriotti, Francesco Dernartin,
Giuliano Longoni,* Mario Manassero,*
Mario Marchionna, Gianluigi Piva, and Mirella Sansoni
We report the synthesis and structural characterization
of the series of clusters l a - d having the general formula
[Ni38Pt,(C0)48Ho-n]"-. These four compounds have all
been isolated in a crystalline state and the structures of
two, l b and l c , have been determined by X-ray diffraction
studies. They constitute the highest nuclearity carbonyl
clusters that have presently been fully characterized by Xray analysis, and preliminary measurements suggest an
unusual magnetic behavior.
(i P r O ) Z T i \/r / T\ i ( O i Pr)2
In spite of their molecular complexity, the synthesis of
the cluster ions 1 is rather straightforward. Variable mixtures of l b and l c are obtained by reaction of the nickel
cluster 2 in acetonitrile with either PtC12 or K2PtCI, in a
ca. 1 : 1 molar ratio; their formation probably conforms to
the stoichiometry of Equation (1).
Scheme 3 .
Received: April 1 I , 1985;
revised: May 17, 1985 [ Z 1264 IE]
German version: Angew. Chem. 97 (1985) 695
CAS Registry numbers:
1, 17872-92-3; 2, 97351-61-2; 3, 97351-68-3; 4a, 97351-69-4; 4b, 91787-39-2;
4c, 97351-71-8; 5a, 97351-70-7; (€)-5b, 74632-96-5; (Z)-5b, 74632-95-4; (i-
PrO)iTiC12, 762-99-2; PhCHO, 100-52-7; cyclopentylphenylsulfone, 1463346-6.
[ I ] a) K. Ziegler, K. Nagel, M. Patheiger, Z . Anorg. ANg. Chem. 282 (1955)
345; b) J. A. Gurak, J. W. Chinn, Jr., R. J. Lagow, H. Steinfink, C. S.
Yannoni, Inorg. Chem. 23 (1984) 3717 (solid-state "C-NMR spectra of
CHiLi and CH2Li2); c) A. Maercker, M. Theis, Angew. Chem. 96 (1984)
990; Angew. Chem. I n / . Ed. Engl. 23 (1984) 995, and references cited
[2] P. von R. Schleyer, Pure App/. Chem. 56 (1984) 151, and references cited
therein; S. Wolfe, L. A. LdJohn, D. F. Weaver, Tetrahedron Lett. 25
(1984) 2863, and references cited therein.
[3] J . Vollhardt, H.-J. Gais, K. L. Lukas, Angew. Chem. 97 (1985) 607; A n gew. Chem. In/. Ed. Engl. 24 (1985) 610.
[4] E. M. Kaiser, L. E. Solter, R. A. Schwarz, R. D. Beard, C. R. Hauser, J .
Am. Chem. Soc. 93 (1971) 4237; J. B. Evans, G. Marr, J . Chem. Soc. Perkin Tram. I 1972, 2502; K. Kondo, D. Tunemoto, Tetrahedron Lett.
1975. 1397, and references cited therein; A. Roggero, T. Salvatori, A.
Proni, A. Mazzei, J. Organornet. Chem. 177 (1979) 31, and references
cited therein: S. P. J. M. van Nispen, C. Mensink, A. M. van Leusen, Tetrahedron Lert. 21 (1980) 3723; M. C. Mussatto, D. Savoia, C . Trombini,
A. Umani-Ronchi, J . Org. Chem. 45 (1980) 4002, and references cited
(51 G. D. ('ooper, J . Am. Chem. Soc. 76 (1954) 3713; K. L. Lukas, Disrertation. Technische Hochschule Darmstadt 1983.
[6] J. Vollhardt, Diplomarheit, Technische Hochschule Darmstadt 1984: S.
V. Ley, N. S. Simpkins, J . Chem. Soc. Chem. Commun. 1983, 1281.
[7] G. Chasaaing, A. Marquet, Tetrahedron 34 (1978) 1399.
[S] I , which was generated by dilithiation of 4a and subsequent protonation, does not contain deuterium in the o-position of the phenyl ring (cf.
also 3).
[9] Detected by temperature-dependent "C-NMR spectroscopic examination of ["Li2/7-"C]-3; S. Braun, H:J. Gais, J . Vollhardt, unpublished.
[lo] G. Fraenkel, A. M. Fraenkel, M. J. Geckle, F. Schloss. J. Am. Chem. Soc.
101 (1979) 4745.
[ I I ] D. Seebach, J . Gabriel, R. Hassig, Helu. Chim. Acta 67 (1984) 1083, and
references cited therein.
1121 Z-5b: m.p. 85-87°C: 'H-NMR (300 MHz, CDC13): 6=0.44 (s, 9H),
7.08-7.20(m,7H),7.26-7.40(m,3H),7.40(~, IH,H-2).--E-5b:m.p.8082°C; ' H - N M R (300 MHz, CDCI,): 6=0.02 ( s , 9H), 7.26-7.35 (m.2H),
7.36-7.45 (m, 3 HJ. 7.88-7.98 (m, 3 H), 8.42 (s, I H, H-2).
Angens. Chem. I n t . Ed. Engl. 24 (1985) No. 8
Id is successively protonated to l c and l b [Eq. (2)] owing to the intrinsic acidity of the platinum-complex starting
material. The clusters 1 can be cleanly separated from impurities (mainly the carbonyl clusters 3"l and 412' and unreacted starting material 213])owing to the differential solubility of their tetrasubstituted ammonium or phosphonium salts in organic solvents. They are generally obtained
in u p to 80% yield (based on platinum) with the remaining
20% being due to the presence of variable amounts of 3
and 4 as well as some platinum metal. The salts of 1 are
readily soluble in acetonitrile, only moderately soluble in
acetone, and sparingly soluble or insoluble in tetrahydrofuran, alcohols, and nonpolar organic solvents.
Owing to the occurrence in acetonitrile solution of a
rapid protonation-deprotonation equilibria [Eq. ( 2 ) ] , the
mixture of the ions l a - d is easily converted into one of
its components by controlled addition of acid or base. The
derivatives l b and l c have been isolated in a crystalline
state with several tetrasubstituted ammonium or phosphonium counterions by precipitation with diisopropyl
ether from acetonitrile solution.[41Isolation of l a is hampered by ready deprotonation of its salts on dissolution
both in acetone and acetonitrile. All the crystalline sam[*] Prof. Dr. G. Longoni, M. Manassero. A. Ceriotti, F. Demartin,
M. Marchionna, G . Piva, M. Sansoni
Dipartimento di Chimica lnorganica e Metallorganica
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exchanger, titanium, synthesis, nmr, dilithio, trimethylsilylmethyl, 13c1h, characterization, phenylsulfonyl, lithium
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