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Lithium-Coordinated -Sulfonimidoyl Carbanions Crystal Study of [(S)-(N-Methyl-S-phenylsulfonimidoyl)methyllithium]4. 2(tmeda) and Configurative Stability of [(N-Methyl-S-phenylsulfonimidoyl)isopropyllithium]

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Lithium-Coordinated aSulfonimidoyl Carbanions:
Crystal Study of
[(S)-(N-Methyl-S- phenylsulfonimidoy1)methyllithium],-2(tmeda) and Configurative Stability of
By Hans-Joachirn Gais,* Irene Erdelrneier,
Hans J . Lindner, and Jurgen Vollhardt
Lithioalkylsulfoximides such as 1 have become firmly
established as analogues of lithioalkylsulfones such as 2,
with an optically stable center of chirality at the S atom, in
the arsenal of methods used in asymmetric synthesis."] In
contrast to 2,12' almost no information is available on the
structure of 1 .[2h.c1 This fact, along with investigations on
lb, R1:R2=Me
2b, R = Ph
2C, R=CH=CH,
the asymmetric induction in the elimination reactions of
B-siloxylithioalkylsulfoximides," prompted us to determine
the crystal structure of [(S)-(N-methyl-S-phenylsulfonimidoyl)methyllithium], .2(tmeda) 3 (tmeda = tetramethylethylenediamine) and the configurative stability of l b at the
a - C atom. Compound 3 was prepared by metalation of
with n-butyllithium
(nBuLi) in TMEDA.14] The single-crystal X-ray structure
analysis of 315](Fig. 1) revealed a tetramer of l a with approximate C z symmetry and having two pairs each of differently coordinated lithium ions and (S)-(N-methyl-Sphenylsulfonimidoyl)methyl anions. The coordination of
two lithium ions by TMEDA and two oxygen atoms of two
anions [average Li . . . N 2.1 O(5) A, Li . . .O 1 1.90(5) corresponds to that found for 2a and 2b.[*"]The two other
lithium -ions in close proximity to each other [Li- . .Li
2.78(5) A] are each coordinated by three nitroge? atoms of
the sulfoximide groups [average Li. . . N 2.09(5) A] and-in
contrast to 2a-c[*''I-by one carbon atom of-each of the
methylene groups [average Li.. . C 2.49(5) A]: S1, N11,
Li3, and C71 as well as S3, N13, Li4, and C73 each form
four-membered chelate rings. Each of the two other methylene carbon atoms, C72 and C74, has contact to the two
central lithium ions Li3 and Li4 [average L i . . . C
3.24(4) A]. The S-Cmerhyleneabonds
[average 1.64(2) A], like
the bond in 2af2"][1.608(3) A], are significantly shorter than
that ip S-methylsulfoximides (average of nine compounds:
1.74 A"]), thus pointing to the double-bond character of
this bond. The methylene carbon, the sulfur, the nitrogen,
and the methyl carbon atoms lie nearly in the same plane
[average of the C7-S-NI-CS dihedral angles 177(6)"].
Information about the structure of 1 in solution-especially about the nature of the bond between the anionic C
atom and the sulfonimidoyl group-was expected to be
obtained from the determination of the energy barrier for
diastereotopomerization[81(AG;,) of the methyl groups in
l b . The diastereotopomerization is effected by rotation
around the C-S bond for a planar configuration of the
carbanionic center and by rotation and inversion for a
pyramidal configuration.
The 75.5-MHz I3C-NMR spectrum of [I3C-9,'3C-10]-1b
(degree of labeling 99%) in [D8]THF[91is temperature dependent."" At room temperature, an averaged signal at
6 = 20.5, which is due to the rapid exchange of the diastereotopic methyl groups, is found for 1b. Coalescence is observed at - 70°C; at - 103"C, separated signals are found
at 6 = 19.4 and 22.4. From the line separation of the signals
of 220 Hz, AG& was calculated to be 9.2k0.2 kcal/mol
for l b at the coalescence point. This reveals that the
carbanions of 1 with R ' # R' are not configurationally
stable at the anionic C atom, even at low temperatures.["]
Received: May 26, 1986;
revised: July 10, 1986 [Z 1789 IE]
German version: Angew. Chem. 98 (1986) 914
CAS Registry numbers:
la, 71098-63-0; Ib, 104091-59-0; 3, 104091-60-3
Fig. 1. Stereoview of the crystal structure of 3
(H atoms omitted). Selected distances
angles ["I: C l I-SI 1.83(3), C12-S2 1.89(2), C13S3 1.82(2), C14-S4 1.86(2), C71-SI 1.67(2),
C72-S2 1.56(2), C73-S3 1.66(2), C74-S4 1.70(2),
C71-Li3 2.53(5), C72-Li3 3.03(5), C72-Li4
3.24(5), C73-Li4 2.44(4), C74-Li3 3.34(5), C74Li4 3.37(5), NlI-Li3 2.01(4), N12-Li3 2.28(4),
N12-Li4 2.06(5), Nl3-Li4 1.97(5), N14-Li3
2.05(4), N14-Li4 2.21(4), Li3-Li4 2.78(5); C71S l - N l bC81 175(6), C72-S2-N12-C82 - 180(6),
C73-S3-N 13-C83 173(6), C74-S4-N14-C84
['I, DipLlng. I. Erdelmeier [+I,
Prof. Dr. H. J. Lindner, DipLIng. I. Vollhardt ['I
lnstitut fur Organische Chemie und Biochemie der Technischen Hochschule
Petersenstrasse 22, D-6100 Darmstadt (FRG)
[*] Prof. Dr. H.-J. Gais
Present address:
lnstitut fur Organische Chemie und Biochemie der Universitat
Albertstrasse 2 I, D-7800 Freiburg (FRG)
This work was supported by the Fonds der Chemischen Industrie and
the Deutsche Forschungsgemeinschaft. I. E. thanks the Stiftung Stipendienfonds des Verbandes der Chemischen lndustrie for a fellowship. We
thank Dr. S . Braun for the NMR spectra.
0 VCH Verlagsgesellschaft mbH. 0-6940 Weinheirn. 1986
[l] C. R. Johnson, J. R. Zeller, Tetrahedron 40 (1984) 1225, and references
cited therein; C. R. Johnson, Aldrichim. Acta 18 (1985) 3, and references
cited therein.
[2] a) Crystal structure analysis: H.-J. Gais, H. J. Lindner, J. Vollhardt, Angew. Chem. 97 (1985) 865; Angew Chem. In?. Ed. Engl. 24 (1985) 859,
and references cited therein (2a): G. Boche, M. Marsch, K. Harms, G.
M. Sheldrick, ibid. 97 (1985) 577 and 24 (1985) 573 (2b); H.-J. Gais, J.
Vollhardt, H. J. Lindner, ibid. 98 (1986) 916 and 25 (1986) 939 ( 2 c ) ;b)
NMR investigations: G. Chassaing, A. Marquet, Tetrahedron 34 (1978)
1399; c) C-H-acidity measurements: F. G. Bordwell, I. C. Branca, C. R.
Johnson, N. R. Vanier, J . Org. Chem. 45 (1980) 3884; d) reactions at the
anionic C atom: J. N. Roitman, D. J. Cram, J. Am. Chem. SOC.93 (1971)
0570-0833/86/1010-0938 $! 02.50/0
Angew. Chem. Int. Ed. Engl. 25 11986) No. 10
2225. E. J. Corey, T. H. Lowry, Tetrahedron Lett. 1975, 193; e) a b initio
calculdtions: I). A. Bors, A. Streitwieser, Jr., J. Am. Chem. SOC. 108
(1986) 1397; S. Woife. L. A. LaJohn, D. F. Weaver, Tetrahedron Lefr. 25
(1984) 2863.
[3] I. Erdelmeier, H.-J. Gais, H.-J. Lindner, Angew. Chem. 98 (1986) 912:
Angen. Chem. Int. Ed. Engl. 25 (1986) 935.
[4] Expemnenml
(240 mg. 1.42 mmol) was dissolved in 3 mL of anhydrous TMEDA and
then treated with a solution of nBuLi (1.41 mmol) in n-hexane (0.9 mL)
at 0' C'. The resulting clear solution was concentrated to ca. 2 mL at
room temperature and lo-' torr. Precipitated 3 was redissolved by
warmtng the solution to ca. 40°C. Upon cooling of the solution to room
temperature, 3 crystallized out in the form of colorless rods or as rhomhic platelets. The crystals were collected by filtration under N1, washed
with n-hexane, and dried (ca 2 min at 25°C/10-' torr).
[ 5 ] A single crystal was mounted in a glass capillary under argon.
u=73.073(2), h=9.731(2), ~=28.300(3)A, @= 119.88(6)O, V=5509.3 A',
1.125 g - c m -', p(MoK.)= 1.7 c m - ' , intensity measurement at
room temperature, Siemens four-circle diffractoineter, MoKo radiation,
graphite monochromator, 4708 reflections (1.5" 5 8 5 2 2 . 5 " ) measured,
2763 bymmetry-independent reflections with I F l t 4 o ( F ) [6l, SHELX, direct methods, H atoms with the exception of those on C71, C72, C73,
C74, and the methylene groups of the TMEDA molecules positioned on
the basis of geometric arguments. 621 parameters, R=O.I 14. Further details of the crystal structure investigation may be obtained from the
Fachinformationszentrum Energie, Physik. Mathematik GmbH, D-75 14
Eggenstein-Leopoldshafen2 (FRG), on quoting the depository number
CSD-52078, the names of the authors, and the journal citation.
[6] We thank Dr. H Paulus. lnstitut fur Physikalische Chemie, for this
[7] D. R. Band, T. A. Modro, L. R. Nassimbeni, J. Wieczorkowski, Phophorus Sulfur 22 (1985) 59; S. Neidle, D. Rogers, J . Chem. Soc. B 1970, 694:
M. D. Cabezuelo, C. Foces-Foces, F. H. Cano, S. Garcia-Blanco, Actn
Crystulloyr. 8 3 3 (1977) 391 I .
[XI G. Biiisch, E. 1. Eliel, H. Kessler, Angew Chem. 83 (1971) 618; Angew.
Cheni. In!. Ed. Engl. I0 (I97 I ) 570.
191 [Me"'(MeY)C'-S(0)(NMeH)Ph'-"]Li
Ib, 75.5-MHz "C-NMR data
[[D,]THF, 25"C, [Dx]THF (6=25.3) int.] of Ib. Values in curly brackets:
75.5-MHz '.'C-NMR data (CDCI,, 25°C. TMS int.) of N-methyl-S-isopropyl-S-phenylsulfoximide.6=20.5 (C-9, C-10) 115.6, 16.31, 30.4 (C-8)
129.5). 38.2 ['J("C,"C)=38.3 Hz] (C-7) 155.7 ['J("C,''C)=34.8 Hz},
142.0 (C-I) 1135.71, 128.5, 127.8 (C-2, C-3, C-5, (z-6) 1129.3, 130.31, 127.9
(C-4) 1132.7).
[lo] Line-broadening but not coalescence was observed in the 300-MHz ' H NMR spectrum of la and of Ib in [D,]THF down to - 100°C.
[ I l l The determination of the rate-limiting step in the topomerization of l b
having a nonplanar configuration of the anionic C atom-rotation o r
inversion-is not possible o n the basis of these results. However, o n account of the reduced pyramidalization and the R delocalization of the
carbanion. AGZ, should be smaller than AGE,, [2, 121.
[ 121 J. Kaneti. P. von R. Schleyer, T. Clark, A. J. Kos, G. W. Spitznagel, J. G.
Andrdde. J. B. Moffat, J . A m . Chem. Soc 108 (1986) 1481.
Solid-state and Solution Structure of
By Hans-Joachim Gais,* Jiirgen Vollhardt, and
Hans J . Lindner
Monometalated allylsulfones play an important role as
reactive intermediates in organic synthesis,"' for example,
in the preparation of specifically functionalized diquinanes,'Ih1in the synthesis of dilithiated (phenylsulfony1)allyl compounds,"h1 and in asymmetric C C bond formation
in the presence of chiral amines.["l In contrast, the question of their structure, which is not only important for the
[*] Prof. Dr. H.-J. Gais ['I, Dipl.-lng. J. Vollhardt [+I,
Prof. Dr. H. J. Lindner
lnstitut fur Organische Chemie und Biochemie der Technischen Hochschule
Petersenstrasse 22, D-6100 Darmstadt (FRG)
['I Present address:
lnstitut fur Organische Chemie und Biochemie der Universitat
Albertstrdsse 21, D-7800 Freiburg (FRG)
[**I This work was supported by the Fonds der Chemischen Industrie. We
thdnk Dr. S. Braun for the NMR spectra and Dr. H. Paulus, Institut fur
Phy\ikalische Chemie, for the unit cell parameters.
Angew Chem. In1 Ed. Engl. 25 11986) No. 10
interpretation of stereochemical results, has not yet been
answered; thus, no X-ray structure analyses or N M R in.
vestigations are available.[*'
H. L
2 , R = P h , L = trneda
3, R = CH=CH2. L = diglyrne
The crystal structures of two lithiated aZkykulfones[(phenylsulfonyl)methyllithium.(tmeda)], 1 and [a-(phenylsulfonyl)benzyllithium~(tmeda)], 2[3h1(tmeda = tetramethylethylenediamine) - as well as of several allyllithi~m'~
not containing sulfonyl groups, such
as 4 y 1have been reported. Whereas the former display no
C-Li contacts, but only 0-Li contacts and short C-S
bonds, q'-complexation of the lithium ion and bond equalization in the anion is observed for the latter-with one
Which type of bonding dominates for the a-(sulfony1)allyllithium compounds, that with C-Li or that with 0-Li
We report here on the crystal structure of [a-(phenylsulfonyl)allyllithium .( d i g l ~ m e ) ]3~ (diglyme = diethyleneglycol dimethyl ether), an allyllithium compound with an acceptor substituent that is important for synthesis,lcl and on
the N M R investigations of the structure of a-(phenylsulfonyl)allyllithium 5at6]in solution.
Compound 3 was prepared by metalation of allylphenylsulfone with n-butyllithium ( n B u d ) in diglyme."' The
X-ray structure analysis of 3Ix1reveals dimers with a crystallographic center of inversion (Fig. I), such as are also
found in 1 and 2 , despite the change in the chelate ligand.
The arrangement of the diglyme molecules results in a distorted trigonal-bipyramidal pentacoordination of the Li
atoms by the 0 atoms; C-1 to C-3 of the ally1 group
bonded to the S atom lie outside the coordination sphere of
Li. An interaction of the q3-x-allyl type is not observed.
The anionic C-1 exhibits clear pyramidalization. H- 1
and C-2 are displaced toward the phenyl ring, as revealed
by the dihedral angle around the SI-CI bond (Fig. 2). Similar results were found for the anionic C atom of 1 (Fig.
2)-although in that case more pronounced flattening was
observed. The configuration corresponds to a nearly middle position between sp' and sp2 hybridization.[" However, one might have expected further flattening at C- 1 in going from 1 to 3 on account of the additional conjugation
of the sulfonyl carbanion with the double bond.12.7h'('l The
SI-Cl bond (1.668(8) A) is longer than that in 1 and approximately the same length as that in 2, but considerably
shorter than in s~lfones.['~
Together with the length of the
bond between C-1 and C-2, that between C-2 and C-3, and
the dihedral angle around the CILC2 bond (Fig. I), this
indicates the presence of a conjugated n-electron system.
Interestingly, the Cl-C2-C3 angle is widened, as is the
in contrast to
case in allyllithium c o m p o ~ n d s , although,
such compounds, 3 exhibits no C-Li contacts.
0 VCH Verlagsgesellschaji mhH. 0-6940 Weinheim. 1986
0570-0833/86/1010-0939 $ 02.50/0
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crystals, methyl, methyllithium, stud, coordinated, tmeda, configuration, carbanion, phenylsulfonimidoyl, lithium, sulfonimidoyl, stability, isopropyllithium
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