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Electron-Reservoir Complexes [FeICp(arene)] as Selective Initiators for a Novel Electron Transfer Chain Catalyzed Reaction General Synthesis of Fulvalene-Bridged Homo- and Heterodinuclear Zwitterions.

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Kumarathasan. O,bounometu//ics1991. 10. 2095; f ) D. H. Pae. M. XMO, M. Y
Chime. P. P. Gasper. J. An?. Cliem. Sue. 1991, 113, 1281. g) alkylidenesiliranes:
H. Saso. W. Ando. K. Ueno. Irtraliedron 1989, 45. 1929; h) bisfalkylidene)clhranes: T. Yamamoto, Y. Kabe. W. Ando. Or,pt?umeru//ics 1993, 12,
1996; I ) silirenes: R. T. Conlin. P. P. Gasper. J. At??.Ctien?.So<. 1976. 98. 3715;
J ) H . Sakurai. Y Kamiyama. Y. Nakadaira, rhid. 1977. 99. 3879: k) K. Hirotsu.
T. Higuchi. M. Ishikawa. H. Sugisawa. M. Kumada. J. Chem. S o l . Chern. Comm r n . 1982. 776; I ) D. Seyferth. D. C. Annarelli. S. C. Vick, J Orgunomel. Chern.
1984. 773. 123; m ) germirenes. A. Krehs. J. Berndt. T e t r u h c 4 ~ ~Letr.
n 1983. 24,
4083; n) M. P. Egorov, S. P. Kolensnikov. Y T. Struchkov. M. Y. Antipin. S. V.
Sereda. 0. M. Nefedov. J. Orgunotnrt. Chern. 1985. 290, C27; 0) stannirenes:
L. R. Sita. R. D Bickerstaff. J. Am. Ckem. Soc. 1988. 110. 5208.
[2] Reviens: a ) W. P. Neamann. Chem. Rev. 1991. 91. 311; b) J. Barrau. J. Escudie.
J. Satge. ;hid. 1990. YO. 283. Germirane intermediates were proposed in the
following reports: c) E. B. Norsoph. B. Coleman, M. Jones. Jr.. J. Am. Chern.
Soc. 1978. 100. 994: d ) D. Seyferth, M. Massol. J. Barrau. S. Monteverdi. J.
Orgunornet.Chcrn. 1980. 185, 307; e) J. Kocher, W. P. Neumann. Orgunumetdlics 1985. 4. 400: f ) M. P. Egorov. S. P. Kolesnikov. 0 . M. Nefedov. A. Krebs,
J. Orxrrtiomef. Ciwni. 1989. 375, C5: g) M. Lazraq. J. Escudie. C. Couret, J.
Satge. M. Soufianoui. rhrd. 1990.397. 1 :h) M. Lazraq. C. Couret. J. P. Declercq.
s
9. 845: i)
A. Dubourg, J. Escudie. M. Rivieve-Baudet, O r ~ u r i o m e t a l l r ~1990,
K.L. Bobbltt. V. M. Maloney, P. P. Gaspar, ihid. 1991. f0,2772.
[3] D. A. Horner, R. S. Grev. H. F. Schaefer 111. J A m . Cliem. So[. 1992, 114,2093.
[4] D. E. Goldheg, P. B. Hitchcock, M. F. Lappert. K. M. Thomas. A. J. Thorne, T.
Fjeldberg. A. Haaland. B. E. R. Schilling. J Chern. Soc. Dulfon Truns. 1986,
2387.
[ S ] 3: Colorless crystals, m.p. llX.5'C. 'H NMR (500 MHz, C,D,): d = 0.10 (s.
2 H ) . 0.32 (s. 36H). 2.04 (s. 6 H ) . 2.16 (s. 6H): I 3 C N M R (125 MHz. C,D,):
d = 3 1 ( q ) . 7.7 (d). 24.9 (4). 28.9 (q), 129.0 (5). 135.7 (s); MS:in;:: 500 ( M + ) .
485 ( M I - Me). - 5: Colorless crystals, m.p. 189.3-189.5 C: 'H N M R
Electron-Reservoir Complexes [Fe'Cp(arene)] as
Selective Initiators for a Novel Electron Transfer
Chain Catalyzed Reaction: General Synthesis of
Fulvalene-Bridged Homo- and Heterodinuclear
Zwitterions"*
David S. Brown, Marie-Hklene Delville-Desbois,
Roland Boese, K. Peter C. Vollhardt,*
and Didier Astruc*
Dedicated to Professor Henri Bouas-Laurmt
on the occaJion of his 60th birthday
Many non-redox reactions proceed by the electron-transfer
chain (ETC) mechanism.['.21 We now report ETC catalysis of a
redox reaction, the intramolecular disproportionation of dinuclear fulvalene carbonyl complexes in the presence of PR,
(R = Me, OMe).[31The result is the cleavage of the metalmetal bond, replacement of one CO by two PR, ligands at a
single metal center, and intramolecular electron transfer
[Eq. (a); R' = H, Me in the Fe catalyst]. The starting materials
and products are listed in Table 1.
(400MHz.C,,D,):6=-0.01(s.2H).0.24(~,36H).1.97(s.12H).7.04(t,1H).
7.1X It. 7 H ) . 7.80 (d. 2H): 13CNMR (100 MHz. C,D,): 6 = 3.4 (4). 14.1 (d),
25.3 ( q ) . 63.9 (s). 125.9 (d). 127.5 (d). 128.8 (d), 132.7 (sj. 135.3 (s), 157.5 (s):
MS: i d ; : 675 ( M I ) . 660 (M' - Me). - 6:Colorless oil: ' H N M R (500 MHz,
C,D,): 6 = 0 . 3 0 ( ~2, H ) . 0.35(s, 18H). 0.41 (s. 18H), 0 . 6 0 ( ~1. H). 1.55(d. 3 H ) ,
1.64 (d, 3 H ) . 1.79 (d, 3 H ) . 1.98 (d. 3 H ) . 6.00 (d, 1 H); ' , C N M R (125MHz.
C,D,). 3 = 3.8 (9). 4.3 (q), 11.6 (d), 20.7 (9). 23.7 (qj, 25.7 (q). 26.4 (4). 126.9
(d). 134.0 (s), 138.1 (s). 141.7 (s); MS: mi:: 518 ( M ' ) . 503 ( M t - Me);
HRMS: calcd. for C,,H,,0Si,74Ge 518.2307. found 518.2308. In the COLOC
spectra of 6 olefinic CH and the neighboring quaternary carbons (6 = 126.9 and
6 = 134.0. respectively) show cross peaks to two CH, protons (6 =1.55, 1.79),
while the other olefinic quaternary carbons (6 =138.1. 141.7) correlated with
two other CH, protons (6 =1.64, 1.98). - 8 : Colorless crystals; decomp.
10X.7 C ; ' H N M R (400 MHz. C,D,): 6 = - 0.03(s. 1 H), 0.07 (s, 1 H). 0.15 (s,
IXH). 0.24 (s. 18H), 2.70 (d. 2 H ) , 7.05 (t. 1 H ) . 7.27 (t, 2 H ) . 7.8 (d. 2 H ) ;
I 3 C N M R ( 1 0 0 MHz, C,D,): 6 = 3.1 (q), 3.5 (q), 3.7 (d). 7.1 (d). 29.4(d). 126.3
(d). 127.3 (d), 128.3 (s). 128.8 (d). 173.9 (s): MS: ni/z: 565 (hi'+),550
( M i - Me). 9 . Colorless powder: ' H N M R (400 MHz. C,D,): 6 = 0.02 (s.
Table 1. Summary of the starting materials and products for reaction (a)
Starting
material
Product
I
3
2
5
5
9
6
8
10
13
11
4
M'
M2
n
tn
R
Mo
W
Fe
Fe
Ru
Ru
Mo
W
W
W
Mo
W
3
3
2
2
2
2
3
3
3
3
3
3
Me
Me
OMe
Me
Me
Me
1H~.0.14(s.9H).0.22(s.YH),0.26(s,YH),0.36(s.YH).0.45(s,lH),2.32(s.
1 H). 2.72 (dd. 1 H. JAR=10.1 Hz, JHc=17.7 Hz),2.81 (dd, 1 H. JAR=10.1 Hz,
J,,=4.90H~).2.93(dd,IH.J,,=4.90Hz,J,=17.7Hz).7.05(t,1H).7.22
( t . 2 H ) . 7 . 5 3 ( d , ? H ) ; l 3 C N M R ( 1 0 0 M H z , C 6 D 6 ) : 6 = 3.3(q).3.5(q), 3.6(q),
3.8 (q). 9.5 (dj. 11.6 (d). 32.3 (t), 34.9 (d), 126.5 (d). 128.2 (d), 128.9 (d). 133.0
(s). 175 O(s).17X.6(s);MS:m/;:583(Mt).568(Mt - Me);HRMS:calcd.for
C,,H,,O,NSi,"Ge
583.1844, found 583.1844. In the C-H COSY spectra of 9
the sienal for the CH, carbon (6 = 32.3) shows cross peaks to H" (6 = 2.72) and
H' ( h = 2.93). The J values of HA (2.81 Hz). HB, and HCestablish the proton
connectivities and the fruns relationship between HA and H'. The four Me,Si
signals in the 'H and
N M R spectra of 9 are assigned to the two
diastereotopic (Me,Si),CH groups, since the carbon attached to germyl substituent is chiral and each Me,Si group is also diastereotopic due to the unsymmetrically substituted germanium.
M , = 499.6, triclinic with u = 9.217(6), h =
I61 Crystal data: 3: C,,H,,GeSi,.
ll.3X4(8j. c =15.861(9) A, 1 =76.60(4), b = 87.33(4). 7 =72.78(5)'. V =
1545.9A.'. s p a c e g r o u p P - l . Z = 2 , ~ ( M o , , ) = 1 1 . 4 c m ~ ' . ~ , , , , , = l . l S g c ~ n - ~ .
5: C,,,H,,GeSi,N,O,,
M , = 674.73. orthorhombic with u =15.157(1), h =
15.546(1).c' =16.059(1j A. V = 3784.1
space group Phcn, Z = 4, p(MoK,)
= 9.5cm-l.
= 1.189 cm-'. 8: C,,H,,NO,Si,Ge,
M , = 624.62. triclinic
with (1 = 9.454(1). h =15.905(3), c = 21.086(4),&, a = 87.50(2). fl =79.04(1),
~ = 8 8 9 0 ( 1 ) . . V = 3 1 0 9 . 8 , & 3 . spacegroup P-1,Z = 4 , p(MoK,)=11.Scm-',
e,,,,, = 1 . 3 3 gem-'. The2175(3). 1411 (5),and2637(8)independent reflections
[2N 5 50 : lE2l > 3ulF,2I]weremeasuredonanEnraf-NoniusCAD4diffractometer using Mo,, irradiation and w-20 scan. An empirical absorption correction based on a series of Y-scans were applied t o the data (0.82/1.00 for 3;
0.92'1 .OO for 5 : 0.863/0.999 for 8). The structures were solved by direct methods,
and all non-hydrogen atoms were refined anisotropically to R = 0.065
( R , = 0.076), R = 0.066 ( R , = 0.077) and R = 0.066 ( R , = 0.081) for 3,5. and
8. respectively. Further details of the crystal structure investigation may be
obtained from the Fachinformationszentrum Karlsruhe, D-76344 EggensteinLeopoldshafen (FRG), on quoting the depository number CSD-57793. the
names of the authors. and the journal citation.
A',
Angew. Clicwi. lnr. Ed. Engl. 1994, 33, Nu. 6
8 VCH
Electron-reservoir complexes [Fe'Cp(C,R,)] ,141 the most electron-rich, stable neutral compounds known (based on ionization potential valuesr5b1),
are ideal mediators allowing reduction
at very negative potentials (Eo = - 1.3 to - 1.9 V vs. SCE).['I
They can be used in precise amounts, and their redox potentials
[*I
Prof. K. P. C. Vollhardt, Dr. D. S. Brown
Department of Chemistry, University of California
and
Chemical Sciences Division, Lawrence Berkeley Laboratory
Berkeley CA 94720 (USA)
Teiefax: Int. code + (510)643-5208
Prof. D . Astruc, Dr. M.-H. Delville-Desbois
Lahoratoire de Chimie Organique et Organomitallique
U R A CNRS no 35, Universite Bordeaux I
351 Cours de la Liberation, F-33405 Tdence Cedex (France)
Telefax: Int. code 56846646
Priv.-Doz. R. Boese
Institut fur Anorganische Chemie der Universitit-Gesamthochschule Essen
Universitatsstrasse 3- 5, D-45117 Essen (FRG)
TeleFax: Lnt. code (201)183-2535
[**I This work was supported by the University of California at Berkeley and the
Universite Bordeaux I, the Centre National de la Recherche Scientifique
(CNRS). the Region Aquitaine, the National Science Foundation (NSF),
NATO (CRG 900479). and the Director of the Oftice of Energy Research,
Office of Basic Energy Sciences, Materials Science Division of the U S Department of Energy (DE-AC-03 76SF00098).
Verlugsgesellschufi mhH, 0-69451 Weinhrim,1994
+
+
0570-~1833/94/0606-061
B 10.00
+ .25!0
661
COMMUNICATIONS
E:eI,FeIL
can be adjusted by the choice of the ring substituents,
which provides selectivity, as will be shown here."]
With these Fe' initiators, the ETC-catalyzed synthesis of fulvalene-bridged homo- and heterobimetallic zwitterions proceeds very smoothly (20 "C, a few minutes) in good yields. The
ready synthesis of organometallic zwitterions bridged by a ligand with a delocalized x-electron system has potential, for instance, for the preparation of materials with nonlinear optical
properties.[61Some of the zwitterions could be synthesized thermally, but the reactions needed heating for days, gave low
yields, and required decomplexation of one metal center."]
The respective prototypical homodinuclear M o and W fulvalene carbonyl complexes 1 and 31s1react with excess PMe, in
T H F in the presence of 0.1 -0.2 equiv [Fe'Cp(C,Me,)] (14)
( E o = - 1.55 V vs. SCE, in dimethylformamide (DMF)) to give
the zwitterions 2 ( 6 0 % ) and 4 (70%), respectively. in a few
minutes at 20 'C. Monophosphane zwitterions are not detected.
For the heterobimetallic F e w complex 5,[*l we know that
reduction differentiates the two metal centers (recognition),
since two distinct one-electron waves were found (W reduction
at -1.05 V vs. SCE, Fe reduction at -1.6 V vs. SCE. in
T H F ) .l9I Thus, single-electron reduction of 5 provides the radical anion Fe'W-. and the ligand-exchange reactions with PR,
(R = Me, OMe) proceed at the radical iron center in the chain
propagation step. ETC catalysis can be initiated by either 14 or
[Fe'Cp(C,H,)] (15) ( E o = - 1.30 V vs. SCE, in D M F ) . owing
to an exergonic electron transfer in the initiation step
(AGO < -24 kJmol-' with 15). Not unexpectedly, cobaltocene
proved an inefficient initiator. since its E o value (- 0.9 V vs.
SCE) is too low.['o1Complex 7 undergoes (like 5) ETC reaction
initiated with 14 to give zwitterions 6 and 8 [Eq. (b); R' = H. Me
in the Fe catalyst]. Only the bis-PMe, complex 8 forms upon
reaction with PMe,, which indicates that PMe, displaces
P(OMe), during the ETC reaction.
F-F
Fe-
L'
'co o& \'co
co
-
cat :0.1 0.2 equiv
+ ZPMe,
[ Fe'Cp (Cp; ) 1
- L
THF, 20 "C, 5 rnin
oc,
co
I
.co
q&
(b)
Me, P / F \ e l C o
P Me,
8
5, L = C O
7 , L = P (OMe),
79%
75%
Of particular interest is the RuW complex 1 1 , since differentiation between the two metal centers is not observed by cyclic
voltammetry; instead an irreversible two-electron reduction to
the dianion [Fv[W(CO);)(Ru(CO), ) ] occurs.[91The ETC reaction. however, does differentiate between the two metal centers,
since two PMe, ligands are bound regiospecifically at the Ru
center [Eq. (a)]. ETC-catalyzed syntheses provide either the
monophosphane zwitterion 12 (the only one in the series) or the
diphosphane zwitterion 13, depending on the reductive power of
the electron-reservoir complex. Using 14 as the initiator specifically leads to 12. whereas the use of [Fe'(C,Me,)(C,Me,)] (16)
( E o = - 1.85 V vs. SCE in D M F ) provides only 13. Accordingly, it is also possible to synthesize 13 from 12 when 16 is used as
the ETC initiator (Scheme 1).
Note that the first reaction (11 4 1 2 ) represents an ETC catalysis of net phosphane addition, a simple but new reaction,
whereas the second (12 -13) is only a classical substitution of
C O by PMe,. Despite the simplicity of ETC-catalyzed substitution reactions, there are very few reports of such a reaction for
662
,I; V C H V~r/up.~pecll.schu/r
mbH, D-694.71 Wcinlieini, 1991
oc.
COco
cat: 0.15 equiv
[Fe'Cp(C,Me,)]
Ru-
14
+PMe,
Me,P/R\U\Co
11
co
Me3P/quk0
PMea
13
Scheme 1 ETC reactions starting with 11.
mononuclear complexes.[2b,"1 This is because of side reactions
of the radical anion involved in the chain propagation step. The
efficiency in the reactions described here is explained by the
effectiveness of the fulvalene ligand as an electron sink, similar
to clusters.[*"% The remarkable selectivity indicates that the
electron transfer between 12 and 14 is too endergonic to occur.L131
Since C p permethylation (14 -16) shifts the E o value of
the initiator negatively by 300mV, reduction of 11 by 16 is
exergonic, thus very efficient.
The molecular structure of the zwitterions was proven by
elemental analysis, high-resolution H,13C,and 31PN M R spectroscopy, and mass ~pectrometry."~'In the case of 8, the X-ray
crystal structure" 51 shows
the unti conformation of
the two metal complex
0
I
fragments (Fig. I ) , which
is most probably common
to all the zwitterions re02
ported here. Cyclic voltammetry was used to monic11
C
tor the ETC-catalyzed pro2
^.^
cess by following the disappearance of the starting
complexes and appearance
'18
of the zwitterions. (Details
'4
will be provided in a full
paper.)
In conclusion. we have
carried out a series of
Fig. 1 Crystal structure of 8 (ORTEP).
'
ETC-catalyzed reactions
providing fulvalene-bridged homo- and heteronuclear zwitterions. The selectivity, generality, and efficiency of this reaction,
as well as the role of three Fe' electron-reservoir ETC initiators,
was demonstrated.
Experimental Procedure
Under inert gas a Schlenk tube was charged with the fulvalene dimetal carbonyl
complex (0.1 mrnol) and T H F (10 mL): PR, (100 pL, 1 mmol) was added by syringe. followed by a solution of Fe'complex (0.01 mmol) in dimethoxyethane. After
5 min analysis by thin-layer chromatography (silica gel. 1;l THFjhexane) indicated
that no starting material remained. The solvent was removed in vacuo The residue
was dissolved in MeCN and filtered through a plug of Celite (1 x 4 cm). The solvent
was removed in vacuo and the residue recrystallized from acetone/ether at -78 'C
or - 3 0 ' C .
Received: October 6, 1993 [Z 6400 IE]
German version: Angew. Ciiem. 1994, 106, 715
[l] a) The first ETC-catalyzed reaction: H. Taube, R. L. Rich, .
I
Am. Chrm. SCJC.
1954, 76,2608; b) comparative review, of ETC catalysis in molecular chemistry:
M Chanon, A < < , .Ckwi Res. 1980, 13, 23; c) L. Eberson, Elecrron Tranfer
0570-0833;94;0606-0662S 10 OO+ . 3 : 0
AnRew. Ch em Ini. Ed. Eng/. 1994, 33, ivo. 6
COMMUNICATIONS
Rrui,rions ill Organic Cheniistrv, Springer. Berlin, 1987: d ) J.-M. Saveant. Acc.
Ckerri. Res. 1980. 13, 323: e) J. K. Kochi, J. Orgunonwt. Chem. 1986. 300. 139.
[2] a) D Astruc. Angeu. Chem. 1988, 100,666; Angew. Chein. I n r . Ed. Engl. 1988.
27. 643: Con?mcnts Inorg. Chem. 1987, 6, 61; Acc. Ckem. Res. 1991, 24. 36; b)
W, Kaiin. J Orgmioiiier. Chem. Libr. 1980, 22, 173; c) J. Heinze. Angeu,. Chem.
1984. 96. 823: Angen. Chem. I n t . Ed. Engl. 1984. 23. 831.
[3] For the photochemically initiated disproportionation of metal carhonyls. see:
a ) D R . Tyler. Prog. InorR. Chern. 1988.36, 125; h) D R. Tyler, F. Mao, Coord.
Chon. Rev. 1985. 97. 199.
[4] Besides ETC initiation, the two major functions of electron-reservoir complexes are: 1 ) stoichiometric electron transfer for the activation of molecules
and in material science. and 2) redox catalysis: D. Astruc. Acc. Clieni. Res.
1986, 1 Y . 377: New J Chem. 1992. 16. 305.
[5] a ) J -R. Hamon. D. Astruc. P. Michaud, J. A m . Chern. Soc. 1981, 103, 758; h)
J. Green, M. R Kelly. M. P. Payne. E. A. Seddon, D. Astruc. P. Michaud.
Orgnrior?ictu/iiis 1983. 2. 21 1 : c) for the preparation of the Fe' complexes, see
ref [5a] and D. Astruc, J.-R. Hamon, M. Lacoste, M.-H. Deshois. A. M.
Madonik. E . Romlin in Organometu/lic Synthecis, Voi. 4 (Ed.: R. B. King),
Elszvier. Amsterdam. 1988. pp. 172-187.
[6] a ) R. W. Boyd. Nonlinear Optics, Academic Press, New York, 1992. h) S. R .
Marder, D. N. Beratan, L. T. Cheng. Science 1991.252. 103: c ) W. M. Laidlaw,
R G . Denning. Naturi, 1993, 363. 58.
[7] a ) For instance. the non-ETC-catalyzed synthesis of 10 required heating
[ R U ~ ( F V ) ( C O(Fv
) ~ ]= fulvalene) with PMe, for 2d to give [Ru(Fv)(CO)(PMe,)J. which was then metalated with [Mo(CO),(MeCN),]: M. A. Huffman, D. A Newman, M . Tilset. W. B. Tolman. K. P. C. Vollhardt, Organom o r i l l i c s 1986. 5. 1926: h) M. Tilset. K. P. C . Vollhardt, rbrd. 1985. 4, 2230.
[XI K . P. C. Vollhardt. T. W. Weidman, Organonietullic.~1984, 3, 82.
[9] a ) M - H Delville-Desbois. D. Brown. K. P. C. Vollhardt. D. Astruc, J. Chrni
So< ('hem. Comrnun. 1991, 1355: b) D. Brown, M.-H. Delville-Deshois,
K . P. c'. Vollhardt, D. Astruc, Nevi J Chem. 1992, 16. 899.
[lo] a) W E. Geiger, J A m . Cheni. Soc. 1974. 96, 2632: for the electrochemistry of
di- and polynuclear organometallic complexes see: h) W. E. Geiger, Prog. Ino,x. C h r m 1985. 33. 275; c) W. E. Geiger, N. G . Connelly. Adr. Organonw't.
Chcni. 1985. 24. X7: d ) P. Lemoine, Cuom. Chem. R C P 1982, 38, 55: i l d . 1988.
64. 169.
[I I ] a ) P Lahuerta. M. Latorre. H. Sanau. H. Kisch, J Orgonoinel. Cheni. 1985,
280. C27: b ) B. Olhrich-Deussner, R. Gross, W. Kaim, h i d . 1989, 366, 155.
.[12] For a comprehensive example of study of ETC exchange of CO by phosphdnes
i n clusters see: K . Hinkelmann. J. Heinze. H. T. Schacht. T. S Field, H .
Vahrmkamp. J. Am. Chem. Soc. 1989. lil. 5078.
[13] a ) R. A. Marcus. J Chenz. Phvs. 1956. 24. 966: h) R . A. Marcus. N. Sutin,
B i o < ~ / i iB
~ii~. p h ? . \Actu 1985, X11. 265.
[I41 2: See ref. [7h]. -4: M . Tilset, Dissertation. University of California at Berkeley, 1986. 6: M.p. 128-129 'C: ' H N M R (400 MHz, CD,CN): 6 = 5.63 (t.
J=2.4Hr,2Hj,5.14(t.J=2.4Hr,2H),5.12(m,2H).4.96(t,
5=1.9H~.
2 H ) . 3.68 (m. 18H): "C('HJ N M R (100 MHz, CD,CN)- 6 = 225.86,215.06,
106 61. 90.75. 86.55, 86.32, 83.92. 79.48, 54.45 (t. J(P,C) = 3.7 Hz); " P ( ' H / N M R (121.5 MHz. CD,CN). 6 =167.97, IR(CH,CN): i=19X5. 1895.
:
( M i - CO). 672 (26.2) ( M i ZCO),
1783 cni- I ( C O ) .MS: ndz ( Y O )700(10)
616 (36.8) ( M i 4CO). 520 (18.1) ( M + P(OMe), - 3CO), 492 (34.4)
( M ' - P(OMe), - 4CO): satisfactory C,H analysis. - 8: M.p. >250 -C (decamp without melting), ' H NMR (400 MHz. CD,CN). 6 = 5.57 (t.
J = 2 . 3 H z . 2 H ) , 5 . 1 2 ( t , J = 2 . 3 H z . 2 H ) . 4 . 8 7 ( t , J = 2 . 0 H z , 2 H ) . 4 . 8 1 (t.
J = 2 3 Hr. 2 H j , 1.48 (m, 18 H): '.'C{'H} N M R (100 MHz, CD,CN):
6 = 226.20. 217.32. 105.08. 92.93, 86.26. 85.87. 84.93, 78.27, 21.28 (t,
J(P,C) =16.2 Hz): "P{'H) N M R (121.5 MHz. CD,CN): d = 25.33;
IR(CH,CN): i =1958. 1895, 1785 cm-I (CO); FAB-MS (nitrobenzylalcohol): 1 7 1 : : 632 ( M ' ) : satisfactory C,H analysis. 10, 13: see ref. [7a]. - 12:
M.p. 1 3 0 0 C (decomp.); 'H N M R (400 MHz. CD,CN): 6 = 5.69 (t,
J = 2.1 HL 2 H), 5.62 (t. J = 2.4 Hz. 2 H), 5.57 (t, J = 2.1 Hz, 2H). 5.14 (t.
J = ~ . ~ H 2L H, ) . 1.68 (d. J = I l . S H z , 9 H ) ; "Cl'H) N M R (100MHz.
CD,CN): 6 = 245.82. 225.54. 110.44, 89.13. 86.84. 86.24, X5.63, 81.61, 20.76
(d. ./(P.C) = 36.7 Hz). " P l ' H ) N M R (121.5 MHz, CD,CN): 6 = 6.62.
IR(CH,CN): F = 2003, 1899, 1796. 1789 cm-' (CO); high-resolution MS
(FAB): M H ' calcd for C,,H,,0,P9'Ru'82W 625.9433; found 625.9431.
[I 51 X-r;iv structure determination of 8: A crystal with the approximate dimensions
of 0.39 x 0.31 x 0.23 mm3 was measured on a Nicolet R3mjV diffrdctoineter
with Mo,, radiation at room temperature. Cell dimensions, refined from the
diffractometer angles of 50 centered reflection% are (1 = 9.766(1).
h =10.973(1), c =12.536(2)A. 1 =77.60(1), fl =73.43(1), ;'= 81.13(1)'.
I' = 1242.5(3) A' with Z = 2,
=1.720 gem-'. p = 5.33 mm-' in space
group Pi. R = 0.0393 and R , = 0.0426 for 8250 reflections with F 2 4u(F).
Further details of the crystal structure investigation are available on request
from the Fachinformationszentrum Karlsruhe, D-76344 Eggenstein-Leopoldsh a h . on quoting the following number CSD-5723X, the names of the authors.
and the journ:il citation.
3-Phosphonio-l,2-diphosphaindenidesand the
Electrophilic Substitution of C-Phenyl-Substituted
Ylides**
Georg Jochem, Alfred Schmidpeter,"
M a r t h a Thomann, and Heinrich Noth
A C-phenyl-substituted phosphonium ylide R,P=CR-C,H,
can also be regarded as an ylide-substituted benzene. Although
textbooks d o not include ylides in the list of substituents affecting electrophilic aromatic substitution. indubitably they should
belong to the class of rate-increasing, op-directing substi tuents.
Indeed, C N D O calculations on compounds of this type indicate
a strong perturbation of the benzene n-electron system by an ylide
substituent, which is in agreement with their photoelectron spectra. In addition, upfield shifts of the ' 3C N M R signals relative to
the benzene resonance confirm the calculated charge transfer
from the ylide carbon atom to the carbon atoms in the orrho and
para positions."] To our surprise we could not find any examples
of electrophilic substitution reactions at the C-phenyl ring of an
ylide. During the preparation of C-chlorophosphino- and Cbromophosphino-ylideslZ1 we recently encountered an unexpected side reaction, which comprises this type of substitution.
Further examples were found during model reactions to determine the reaction pathway.
The reaction of benzyltriphenylphosphonium bromide ( 1 ) with
phosphorus trichloride or tribromide and triethylamine leads to
the C-dihalophosphino-C-phenylylides 2.['] In addition, in both
cases the formation of a further product, which presents a conspicuous ABC spin system in its 3'P(1H} N M R spectrum. is
observed and was identified as 1,2-dihalo-3-triphenyIphosphordnediyl-l,2-diphosphaindane3 (Table 1) .I3]Its yield increases
+
Ph,P-CH,-Ph
Br-
1
2a
X=CI
3a
2b
X=Br
3b
~
~
~
Tdhle 1. " P N M R data for the 1.2-diphosphaindanes 3 and 5, and the 1,2-diphi)suhaindenes 6 in CH,CI,. CouDline constants J in H7.
~
3a
3 C [d]
3d [a]
3b
3e [a1
3f [a1
5
6a
6b [a]
6c la1
(1'
78.7
78.9
75.8
61.0
61.8
57.6
6.9
229.4
229.1
218.8
1X.6
JX 3
18.5
17.7
17.2
17.4
17.3
14.9
14.0
14.4
249.7
248.6
256.3
236.5
235.8
242.7
262.5
480.2
476.1
477.6
96.7
97.6
96.1
91.4
91.5
9.0
3.8
3.0
30
4.5
6.1
6.1
6.9
X6.2
87.5
87.0
87.0
4.5
[a] The assignment as the 5-methyl and 7-methyl isomers is preliminary
[*I
Prof. Dr. A. Schmidpeter. DipLChem. G Jochem, Dr. M. Thomann,
Prof. Di-. H. Noth
Institut fur Anorganische Chemie'der Universitdt
Meiserstrasse 1 , D-80333 Munchen (FRG)
Telefdx: Int. code (X9j5902-578
This work was supported by the Deutsche Forschungsgemeinschaft and the
Fonds der Chemischen Industrie. We wish to thank Dr. Karaghiosoff for
obtaining the 2 D N M R spectra. which were essential for the structural elucidation of lob.
+
[**I
Angen . ('hem. l n r . Ed. Engl. 1994, 33, N o . 6
132.4
134 3
330.8
3 54.2
156.8
155.8
178.6
317.1
314.7
309.2
VCH Verlug.~gesellschuftrnhI1, 0-69453 Wr.mlieim, 1994
0j70-0H33:94i0606-0663
B 10.00 + .2.5;0
663
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feicp, initiator, homo, reaction, chains, zwitterion, general, bridge, selective, reservoir, electro, complexes, heterodinuclear, catalyzed, synthesis, arena, transfer, novem, fulvalene
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