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Bis(tricarbonyliron)-para-quinodimethanes Preparation and Molecular Structure.

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ranediyl-protective groups formed therefrom in the presence of ethyldiboranes(6) can readily be removed with met h a n ~ l / g l y c o l . The
[ ~ ~ per-0-acetyl derivatives[8"' l l b to 20b
are prepared from the product mixture and can be separated chromatographically and characterized spectroscopically (MS, NMR).Iah1
The 0-glycopyranosides la to 10a react with varying
rates on reduction with ethyldiboranes(6); 4a and 9a are
reduced especially slowly. By increasing the amount of
MSBNN (cf. Table 1, footnote [a]), the formation of pyranosylalditols in the product mixture can be avoided. The
composition of the polyhydroxyether mixtures is influenced by the anomeric configuration of the D-glUCOpyranosides 1 to 4 and the D-galactopyranosides 6 to 10. The
methyl [3-pyranosides 2a and 7a and the phenyl fl-D-galactopyrdnoside 8a afford highly selectively, via endocyclic
C - 0 hydroboration, 1-0-methyl-D-alditols (11, 16 with
80% selectivity) and 1-0-phenyl-D-galactitol (17, 98%), respectively. Octakis-0-(diethy1boryl)cellobiose 4a and octakis-0-(diethy1boryl)lactose 9a preferentially yield the 1-0aldityIalditol~[~~
12 (52%) and 18 and 18' (72%), respectively. In contrast, octakis-0-(diethylbory1)maltose 3a affords 12 and 13 practically non-selectively, while octakis0-(diethy1boryl)melibiose 10a gives only 20% 19, and
mainly 1,5-anhydro-~-galactitol
20 and D-glUCit01 14, both
of which are formed as a result of exocyclic C - 0 bond
cleavage (cf. Scheme 1 and Table 1).
The "trehalose" moiety of the octakis-0-(diethylbory1)sucrose 5a is not reduced at the endocyclic acetal
bonds. The quantitative reduction of 5a, however, takes
place regioselectively (88%), showing preference for the
exocyclic C - 0 bond of the furanoside ring. In each case,
44% glucitol 14 and a ca. 1 : 6 mixture of the 2,s-anhydroalditols 15 and 15' formed via an oxycarbenium intermediate are obtained. Reductive pyranoside-cleavage of
5a affords a further 6% of D-glucitol 14 and 6% of 1,5-anhydro-n-glucitol 13 (cf. Scheme 1).
Experimental
Penta-O-acetyl-I-O-phenyl-D-glucitol
17b: MSBBN [3] (0.1g, 0.38 mmol)
was added under protective gas at ii20°C to 1.94 g (3.67 mmol) 8a [prepared
from 1 g (3.9 mmol) of phenyl fi-D-galactopyranoside 8 and 4 m L
(28.4 mmolj of activated triethylborane [4]] and 1.27 g ethyldiboranes(6) [5a]
( I 1.86Oh H", i.e. 15.1 mmol >BH-borane) and the mixture stirred for 4 h at
120°C. After evaporation of the colorless solution in vacua (lo-' torr; bath:
70-80°C) the residue was treated with ii7 mL methanol/l,2-ethanediol
( ~ :2)5 and all volatile components were removed in vacua (lo-' torrj. The
procedure was repeated. The boron-free residue was then treated at 20°C
with 5 mL of acetic anhydride in 5 mL pyridine and, after stirring for 1 hour,
the mixture was evaporated t o dryness. The solid residue was washed with a
little ethanol, then with diethyl ether. The colorless, solid product (m.p.
129-131 " C ) was recrystallized from 20 m L diethyl ether/5 mL ethanol:
1.6g (93%) pure 17b: m.p. 133°C; [a]Z,"=20 ( c = 0 . 3 , CHCI,); H Z (Hydridzahl= hydride number) [8b, 10]=9.9.
I-O-Phenyl-~-galactitol17: A mixture of 17b (404.4 mg, 0.86 mmol) and
ethyldibordnes(6) (952.9 mg, 11.96 mmol >BH-borane) was heated for 2 h at
i
i 120°C. The excess >BH-borane
was destroyed by addition of 20 mL of
methanol (>BH-borane consumed: 8.53 mmol). After removal of volatile
components by distillation in vacua the residue was treated with a further
20 m L of methanol and the resulting solution evaporated to dryness, giving
225 mg (= 100%) 17: m.p. 2 0 2 T ; [alg=7.2 (c=0.4, (H;C),SO).
Received: January 18, 1985 [Z 1139 IE]
German version: Angew. Chem. 97 (1985) 508
CAS Registry numbers'
la, 61553-54-6; 2a, 96532-66-0; 3a, 83823-00-1; 4a, 96613-28-4; Sa, 50612.505: 6a, 96532-67-1; 7a, 96532-68-2; 8a, 96532-69-3; 9a, 96532-70-6; IOa,
96532-71-7. llb, 5139-25-3; 12b, 96532-72-8; 13b, 13137-69-4; 13'b, 5390578-5; 14b, 7208-47-1 ; 15b,65729-88-6; 15'b, 65729-86-4; 16b, 25678-3 1-3; 17,
96532-73-9; 17b, 96532-74-0; 18b, 96614-03-8; W b , 96532-78-4; 19b, 9653275-1; 20b, 13121-62-5.
Angen. Chrm Inr. Ed. Engl. 24 (1985) No. 6
~
[ I ] R. Koster, W. Schussler, unpublished.
[2] Cf. W. V. Dahlhoff, S. Penades-Ullate, R. Koster, 2nd European Symp.
on Carbohydrates and Glycoconjugates, Budapest, August 1983, Abstract S. A-32.
[3] Cf. Houben-Weyl: Methoden der orguni.fchen Chemie, 4th edit., Val.
X111/3a, Thieme, Stuttgart 1982, p. 590.
[4] R. Koster, K.-L. Amen, W. V. Dahlhoff, Liebigs Ann. Chem. 1975. 752.
(51 a) Ethyldiboranes(6) is a collective expression for mixtures of variously
highly ethylated boranes and diboranes(6); R. Koster, P. Binger, Inorg.
Svnth. 15 (1974) 141 : b j here, "0-ethylboron-protected" signifies the
presence of Et,B- and EtB< groups; for clarity, only the EtZBgroups
are shown in the formulas.
[6] Ethyldiboranes(6)-catalyzed reduction of tbe per-0-methyl-0-glycopyranosides of 1 and 2 leads predominantly (290%) to per-0-methylI,5-anhydro-~-glucitolof 13 with R = C H , (cf. Scheme I).
[7] R. Koster, P. Idelmann, W. V. Dahlhoff, Synthesis 1982. 650.
[S] a) Elemental analyses and spectroscopic data (MS, 'H-NMR, " C NMR) of per-0-acetyl derivatives llb to 20b are consistent with the calculated compositions and proposed structures. b) The polyhydroxy ethers 11 to 13 and 15-20, free of protective groups, are obtained from
llb to 13b and 15b to 2Ob by reaction with alkyldiboranes(6) at
2 1 0 0 ° C [cf. W. V. Dahlhoff, R. Koster, J . Org. Chem. 42 (1977) 31511 or
by Zemplen saponification.
[9] In analogy to the trivial names of the I-0-glycosidalditols (e.g. maltitol,
cellobiitol), for the new I-0-alditylalditols we propose the abbreviations
maltdiitol = cellobidiitol, lactdiitol, melibidiitol etc., which are formed
by adding the syllables "diitol" to the parent names.
[lo] R. Koster, L. Synoradzki, Chem. Ber. 117 (1984) 2850.
[ I I] Cf. H. Zinner, R. Kleeschatzky, R. Neels, Chem. Ber. 98 (1965) 1492.
[I21 G. Schomburg, F. Sagheh, unpublished work 1983/1984.
Bis(tricarbony1iron)-para-quinodimethanes :
Preparation and Molecular Structure
By Ali R . Koray, Claus Krieger, and Heinz A . Staab*
The stabilization of highly unstable organic molecules as
tricarbonyliron complexes is well-known in several cases
including cyclobutadiene, trimethylenemethane, and orrhoquinodimethane."] Other highly unstable molecules are
para-quinodimethanes like 1 and 2 which have attracted a
great deal of interest as intermediates in chemical reactions[21 and have been studied spectroscopically at low
temperature^.^^] In this paper we would like to report on
bis(tricarbony1iron) complexes of 1 and 2 , which, to our
knowledge, are the first examples of para-quinodimethanes stabilized as ligands in transition metal complexes.
l : R = H
3:R=H
2: R = CH,
4 : R = CH,
3 and 4 were obtained by rapid dropwise addition of solutions of 1,4-bis(bromomethyl)benzene and 1,4-bis(bromomethyl)-2,5-dimethylbenzene, respectively, in benzene
( = 0.01 mo1/250 mL) into a suspension of Fe,(CO), in benzene ( = 0.05 mo1/250 mL) at 40-45 " C .Evaporation of the
solution, rapid chromatography (silica/cyclohexane), sublimation and recrystallization from hexane yielded 314'
(orange microcrystals, dec. > 150"; 1.1% yield) and 4141
[*] Prof. Dr. H. A. Staab, Dr. A. R. Koray, C. Krieger
Abteilung Organische Chemie
Max-Planck-Institut fur medizinische Forschung
Jahnstrasse 29, D-6900 Heidelberg 1 (FRG)
0 VCH Verlugsgesellschafi mbH. 0-6940 Weinheim. 1985
0570-0833/8S/0606-0521 $ 02.50/0
52 1
(red crystals, dec. > 160°C; 3.4% yield). All spectroscopic
data of 3 and 4 agree well with the assumption of bis(tricarbonyliron) complexes of 1 and 2, respectively.[41
With regard to the bonding sites of the two tricarbonyliron units the molecular structure obtained for 4 by X-ray
analysis was of special interest. Figure l a shows a sideview of the C, structure of the complex, from which the positions of the tricarbonyliron groups above and below the
para-quinodimethane unit and the deformation from planarity of the latter can be seen. The complex consists of
two trimethylenemethane-like sections with short distances
between Fe and C(1), C(4), C(3i) and C(2) [195.2(1),
209.7(1), 220.5(1) and 230.8(1) pm, resp.]. This type of
bonding is also supported by the carbon-carbon bondlengths of the quinodimethane moiety which shows equal
distances for C( 1 ) . . .C(4), C( 1). . .C(2) and C( 1 ) . . . C(3i)
(Fig. lb). Furthermore, the subdivision into two trimethylenemethane parts is impressively demonstrated by the long
bond length of 146.2(1) pm found for the bonds
C(2)...C(3) which are the formal double bonds of the
para-quinodimethane ligand. Theoretical calculations
(EHT-MO) agree well with the complex structure
found.161
As was to be expected on the basis of structures 3 and 4
both compounds react readily with bromine (tetrachloromethane, OOC) to yield 1,4-bis(bromomethyl)benzene
(67%) and
1,4-bis(bromomethyl)-2,5-dimethylbenzene
(63%), respectively. Further reactions which can be rationalized as 'in-situ' generation of the para-quinodimethanes
from bis(tricarbony1iron) complexes are under investigation.
Received: February 1 I , 1985 [Z 1163 IE]
German version: Angew Chem. 97 (1985) 513
CAS Registry numbers:
3, 96453-09-7: 4, 96453-10.0; 1,4-b1s(bromomethyl)henzene, 623-24-5; 1,4-
b1s(bromomethyl)-2,5-dimethylbenzene.
[ I ] Cf. J. M. Landesherg in E. A. Koerner von Gustorf, F.-W. Grevels, 1.
Fischler (Eds.): n?e Organic Chemisrry of Iron. Vol. 1. Academic Press,
London 1978, p. 627.
(21 L. A. Errede, M. Szwarc, Q. Reo. Chem. SOC. 12 (1958) 301: H. E. Winberg, F. S. Fawcett, W. E. Mochel, C. W. Theobald, J . A m . Chem. SOC.82
(1960) 1428; L. A. Errede, R. S. Gregorian, J. M. Hoyt, ibid. 8 2 (1960)
5218: J. H. Golden, J. Chem. Soc. 1961. 3741; D. J. Cram, C. K. Dalton,
G. R. Knox, J . Am. Chem. SOC.85 (1963) 1088; W. F. Gorham, J . Po!yrn.
Sci. A - I , 4 (1966) 3027: J. W. Lown, A. S. K. Aidoo, Can. J . G e m . 44
(1966) 2507; G. W. Brown, F. Sondheimer, J . Am. Chem. Sur. 8 9 (1967)
7116; Y . lto, S. Miyata, M. Nakatsuka, T. Saegusa, J. Org. Chem. 46
(1981) 1043, and references cited therein.
[3] D. J. Williams, J. M. Pearson, M. Levy. J . Am. Chem. SOC.92 (1970) 1436:
J . M. Pearson, H. A. Six, D. J. Williams, M. Levy, ihid. 93 (1971) 5034.
[4] Correct elemental analyses (C, H, Fe) were obtained for 3 and 4 . - 3 : IR
(hexane): v(CO)= 1984, 2040 c m - ' ; 'H-NMR (80 MHz, CDzClz):
6 = 1.76 (s, 4 H ) . 4.27 (s, 4H): "C-NMR (90.5 MHz, CDICI2): 6=38.76,
80.31, 103.47, 211.03; MS: m/z=384 (30?:a, M+).356 (7), 328 (40), 300
(16),272(40), 244(100),216(80), 160(37), 112(21), l04(18),56(l3)[5].4 : IR (hexane): v(CO)= 1980,2038 cm - ' ; ' H - N M R (360 MHz, CDzC12):
6 = 1.75 (s, 6H). 1.79 (d, J = 1.6 Hz, 2H), 2.16 (d, J = 1.6 Hz, 2H), 3.74 (9,
2H): "C-NMR (90.5 MHz, CDlCI?): 6= 19.44, 37.43, 78.39, 102.88,
102.94, 211.34; MS: m/r=412 (3246, M*),384 (X), 356 (37), 328 (16), 300
(37). 272 (100). 244 (73), 216 (3). 188 (72), 160 (20), 132 (54). I12 (24), 56
(35) 151.
[ 5 ] Details about the mass spectrometric fragmentation of 3 and 4 : M. Rentzea, A. R. Koray, H. A. Staab, Tefrahedron Letr. 26 (1985) 2563.
[6] H. Vogler, unpublished results.
Chelate-Stabilized Diphosphene and Diphosphorus
Complexes of Nickel**
By Hans Schafer,* Dieter Binder, and Dieter Fenske
Diphosphenes R-P=P-R have two lone pairs of electrons and a double bond and can therefore coordinate in
different ways to transition metals."] We are interested in
complexes of the q2-type in which only the double bond is
formally bonded to a metal center.'21 This coordination
pattern corresponds to the bonding of olefins to transition
metals.
../ R
.P
A
L,M(\
'I;..\
Fig. I . Side-view (a) and top-view (b) of 4 with bond lengths (pm] and bond
angles ["I. a=643.6(1), h=746.6(1), c=919.6(1) pm, n= 103.31(2),
/1=108.77(2), y=91.42(2)": space group Pi, Z = 1: number o f reflections
measured 2061, number of reflections with 1 > 1 . 9 6 ~ ( 1 )1827: R=0.021. Further details of the X-ray structure analysis of 4 are available on request from
the Fachinformationszentrum Energie Physik Mathematik, D-7514 Eggenstein-Leopoldshafen 2, o n quoting the registry number C S D 51246, the
names of the authors, and the full citation of this journal.
522
0 VCH Verlagsgesellrchaft mbH, 0-6940 Weinheim, 1985
I*]
[**I
R
-
p/ R
L,M+
j/
B
P
.-\
R
Prof. Dr. H. SchBfer, Dip1.-Chem. D. Binder, Prof. Dr. D. Fenske
Institut fur Anorganische Chemie der Universitat
Engesserstrasse, Geb. Nr. 30.45, D-7500 Karlsruhe (FRG)
Transition-Metal Phosphido Complexes, Part 10. This work was supported by the Deutsche Forschungsgemeinschaft and the Fonds der
Chemischen Industrie. The crystal data were collected at the Institut fur
Kristallographie der Universitat.-Part 9: H. Schafer, J. Zipfel, B. Gutekunst, U. Lemmert, Z . Anorg. A& Chem., in press.
0570-0833/85/0606-0522 $ 02.50/0
Angew. Chem. In,. Ed. Engl. 24 (1985) No. 6
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