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Isocyanide Insertion into a Uranium-Carbon Double Bond.

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Table 1. Examples of the kinetics and product ratios [a].
Product ratio
: [R-NO,]
I .2
: [R-CN]
: [R-SCN]
N Me4CIe
k x lo3 [b]
: 1
: 1
: 1
: I
: 1
: I
: I
: 1
: 1
: 1
the ensuing reaction (Fig. 1) can be estimated as being ca.
K,=4.1 L/mol and k,=2.1 x 10-2s-', re~pectively[~].
leads to a value of k,/k, = 30 as a measure of the effectiveness of 1 ("effective concentration'"']) under the conditions mentioned in Table 1. Both the observed acceleration
of the reaction as well as the product control can be interpreted in terms of a "proximity effect'"'] or in terms of an
accumulation of nitrite ions at the positively charged centers of 1 in the complex. This leads to an increase in the
proportion of SN2-reaction and thus to increased attack at
the nitrogen atom instead of the oxygen atom of the ambident anion.
In the case of CN' and SCN' ions the attack at the carbon or sulfur atom, respectively, predominates to such an
extentf6]that 1 no longer effects a change in the product
ratio, though a marked increase in the rate of reaction is
still observed (Table 1).
O n addition of the fluorescence indicator 4, which binds
very strongly to the macrocycle l['a,bl,
the catalyst becomes
inhibited; this also manifests itself in an unchanged product ratio (Table 1).
In contrast to the naphthyl derivative 2, benzyl bromide
3 leads neither to a change in the product ratio nor to a n
increase in the reaction rate, since phenyl derivatives are
far more weakly bound in the cavity of l['a,bl.
This is confirmed by the energies of complexation of 2 and 3 with 1
obtained by N M R spectroscopic measurements (2 :
K,,, = 25, 3 : K,,, = 3.5 L/mol, measured in dioxane/water
(1 : 1) without added salt). The shifts of the 'H-NMR resonances observed only in the complexation of 2 with 1
indicate the formation of the inclusion complex responsible for the catalysis.
The system presented here combines many features typical for an enzyme: Increase in reaction rate, saturation kinetics, substrate specificity, selective control of reaction,
competitive inhibition.
Received: April 9, 1984;
revised: May 28, 1984 [Z 795 IE]
German version: Angew. Chem. 96 (1984) 910
[I] Recent reviews, see references in a) H.-J. Schneider, K. Philippi, J. Pohlmann, Angew. Chem. 96 (1984) 907: Angew. Chem. f n f . Ed. Engl. 23
(1984) 908; b) H.-J. Schneider, W. Miiller, D. Giittes, ibid. 96 (1984) 909
and 23 (1984) 910 as well as c) R. Breslow, Science 218 (1982) 532: d) J.M. Lehn: Biomimetic Cfiemisfry,Kodansha, Tokyo 1983, p. 1, 163; e) I.
0 Verlag Cfiemie GmbH, 0-6940 Weinfieim, 1984
+ 2 A C(comp1ex)
+ Nu --%P(product)
: 1
: 1
[a] I n dioxane/water (1 : I) at 30 "C. Conditions: nucleophile [Nu] 0.43 M ;
substrate [2] or 13) as well as catalyst [ l ] and inhibitor 141 0 . 0 4 3 ~in each
. Rate constant k pseudo-first order [s-'1
case: [5] 0.43 M ; [Me,NCI] 0 . 4 3 ~ [b]
f 10%. Kinetics and product compositions analyzed 'H-NMR spectroscopically.
Tabushi in K. J. Laidler: IUPAC Frontiers oJCfiemistry, Pergamon, Oxford 1982, p. 275; f) E. Weber, Kontakfe 1983, 38, and references cited
PI Open chain polyethylene glycols generally show similar catalytic effects
as the corresponding crown ethers: P. E. Stott, J. S. Bradshow, W. W. Parish, J. Am. Chem. Soc. 102 (1980) 4810.
131 F. P. Schmidtchen, Angew. Chem. 93 (1981) 469; Angew. Chem. I n f . Ed.
Engl. 20 (1981) 466; Chem. Ber. 117 (1984) 725.
[41 K , and k, for the basic reactions
were varied with a computer program (R. Kramer, unpublished) under
the condition [Nu]=const, (excess of Nu, see Table I) until the numerical
integration of the differential equations as well as the measured time-conversion values (linearization according to pseudo-first order possible,
&kcx,,) correctly reproduced the dependence of the k,,, values on the ratio [1]/[2] (see Fig. I).
[5] A. Fersht, Enzyme Sfructure and Mechanism. Freeman, Reading 1977,
p. 42.
[6] a) K. Friederich, K. Wallenfels in Z. Rappoport: The Chemistry of the
Cyano Group, Interscience, London 1970, p. 77; b) R. G. Guy in S. Patai:
"he Chembtry of Cyanates and Their Thio Derivatiues, Wiley, Chichester
1977, p. 823, and references cited therein.
Isocyanide Insertion into a
Uranium-Carbon Double Bond**
By Roger E. Cramer*, K. Punchanatheswaran, and
John W. Gilje*
Carbon monoxide is known to insert into actinoid-carbon double"' and single
However, the chemically similar, but often more reactive, isocyanides have not
been reported13] to undergo similar reactions.
We have previously reported[41that acetonitrile reacts at
the uranium-carbon multiple
of 3 to produce an
imido complex containing a U-N bond with approximately triple-bond character. In related hydrido(organ0)yttrium chemistry, tert-butyl isocyanide inserts into the
Y-H bond of 1 to afford 2[']. The same yttrium hydride
reacts with nitriles to produce dimeric complexes containing bridging alkylideneamido ligands[*I.
[CpzYH(THF)Iz + C N t B u + LCpzY(1)' : p2-HC=NtBu)]z
~ N S 6 ~ 1 1
C p 3 U = C H P P h z M e + CNCeH11 --+ Cp3U
Scheme I . Cp=q'-C5H,, thf=tetrahydrofuran
In view of the affinity of U'" for hard Lewis bases, the
known carbon monoxide chemistry, and related yttrium
chemistry, we investigated the reaction between 3 and cyclohexyl isocyanide. In this reaction C,H,,NC inserts into
the UC double bond in 3 forming a unique uranaazacyclopropene 4 in which both nitrogen and carbon atoms are
[*] Prof. Dr. R. E. Cramer, Prof. Dr. J. W. Gilje,
Dr. K. Panchanatheswaran
Chemistry Department, University of Hawaii
2545 The Mall, Honolulu, HI 96822 (USA)
[**I Uranium-Carbon Multiple Bond Chemistry, Part 6. The support of this
work by the United States National Science Foundation (Grant No.
CHE82-I0244 (J. W. G. and R . E. C . ) ) and by the Petroleum Research
Fund, administered by the American Chemical Society, is gratefully acknowledged.-Part 5: R. E. Cramer, K. T. Higa, J. W. Gilje, unpublished.
0570-0833/84/1111-0912 $ 02.50/0
Angew. Chem. Int. Ed. Engl. 23 (1984) No. 1 1
tightly bonded to uranium. In contrast to metal-carbon single bonds, where CC single bonds form during insertion
reactions, insertion at the U=C double bond leads to a
new unsaturated ligand.
The reaction of 3 and C6HIINC(molar ratio 1 : 1, 1 h) in
ether produces a red solution from which 4 can be isolated
as red crystals in 53% yield after evaporation of the solvent
followed by recrystallization from a 1 : 1 benzene-pentane
mixture. The 'H-NMR spectrum shows paramagnetically
shifted peaks [7], and the IR spectrum is complex, but does
not exhibit a peak at ca. 2136 cm-', a characteristic frequency for C6HIINC["I.
4 can be stored for months in vacuo or under anhydrous
nitrogen, but decomposes within seconds if exposed to the
atmosphere. It is very soluble in aromatic solvents and ethers, but only slightly soluble in aliphatic hydrocarbons.
[3] As this manuscript was being prepared, we learned that C O and
insert into the UC single bond of Cp,U-alkyl complexes: a) D.
G. Sonnenberger, A. E. Mintz,T. J. Marks, J. Am. Chem. SOC.106 (1984)
3484; b) R. D. Fischer and G. Paolucci, personal communication.
[41 R. E. Cramer, K. Panchanatheswaran, J. W. Gilje, J. Am. Chem. SOC.106
(1984) 1853.
151 R. E. Cramer, R. B. Maynard, J. C. Paw, J. W. Gitje, Organometallics 2
(1983) 1336.
[6] R. E. Cramer, R. B. Maynard, J. C . Paw, J. W. Gilje, J . Am. Chem. SOC.
I03 (1981) 3589.
[7] W. J. Evans, J. H. Meadows, W. E. Hunter, J. L. Atwood, Organometallics 2 (1983) 1252.
[8] W. J. Evans, J. H. Meadows, W E. Hunter, J. L. Atwood, J. Am. Chem.
SOC.106 (1984) 1291.
191 'H-NMR (300 MHz, C6D6, 25°C): 6= -13.77 ( I S H , s, Cp3U); 73.13
( I H, d, J (PCH)=27 Hz, HCP); 23.78 (3H, d, J (PCH)=9 Hz, MeP);
15.75, 9.16, 8.67 (4H, 4 H and 2H, each m, PhP); 0.66 (2H, d, J = 4 Hz);
0.50 (1 H, d, J =2.5 Hz); 0. I6 (2 1-1, d, J =4 Hz); - 1.18 (1 H, d, J =4 Hz);
-5.38 (2H, d, J = 4 Hz); -7.68 (2H, br); -11.75 (1 H, s), all C 6 H l l .
[lo] J. Goffart in T. J. Marks and R. D. Fischer: Organometallics of the f Elements, Reidel Publishing, Dordrecht, Holland 1979, p. 482.
[ I l l The structure was solved using Patterson and Fourier methods. The C p
and Ph rings were refined as rigid groups. Isotropic temperature factors
were used for all atoms except U and P, which were refined anisotropjcally. Space group P2,2,2,, a = 13.702(4) A, b = 19.859(3) A,
c = 11.488(3)A, Z = 4 , R,=0.059, Rz=0.067 using 1894 unique reflections with I > 3u(I). Further details of the crystal structure investigations
can be obtained from the director of Cambridge Crystallographic Data
Centre, University Chemical Laboratory, Lensfield Road, Cambridge
CB2 IEW, England. Any request should be accompanied by the full literature citation for this communication.
[12] R. E. Cramer, U. Engelhardt, K. T. Higa, J. W. Gilje, unpublished.
(131 G. Perego, M. Cesari, F. Farina, G. Lugli, Acta Crystallog. Sect. B32
(1976) 3034.
Di-(p-amido)dirhodium Complexes:
Structure of IRhz(p-(NH)znaphth)Iz(CO)z(PPh3)zl
Fig. I. ORTEP representation of 4. Angles ["I: U-N-C2 78(1), U-C2-N 68(1),
N-C2-CI 122(2), C2-N-C3 120(2), P-CI-C2 124(2), N-U-C2 33.8(9), U-N-C3
161(2). For distances, see text.
The X-ray crystal structure of 41111
(Fig. 1) shows that the
molecule contains three Cp rings and an fCN(C6HlI)CHPh2Meligand. The UN distance (2.3 l(2) A)
is not statistically different from that in Cp,UNPh2
(2.29(1)A), where the UN bond otbder is between 1 and
2["l, and the UC2 distance (2.44(3) A) can be compared to
the UC single bond distanceo in Cp3UC4H9(2.43(2) A)"31.
The distance C1C2 (1.33(3) A) is typical of a CC double
bond, the distance PC1 (1.74(2)
is not significantly
shorter than that of P-C single bon$s in phosphonium
ions, and the distance N-C2 (1.39(4) A) is not statistically
different from that of a normal single bond. In contrast,
the length of the CN double bond in 2 is 1.275(6) A[']. The
best description of the bonding is shown in Scheme 1.
Organoactinoid complexes tend to be sterically shielded,
but electronically unsaturatedr4].The formation of 4 demonstrates the tendency of U'" to partially relieve its electron deficiency by interaction with multielectron donor ligands.
By Luis A . Ore*, Maria J. Fernandez, Javier Modrego,
Concha Foces-Foces, and Felix H . Cano
Dinuclear transition-metal complexes and their reactions have been the subject of considerable interest in recent years"]. As part of our studies exploring the use of nitrogen donor ligands for the construction of di- or multinuclear rhodium complexesi2J,we describe a facile route to
di(p-amido)dirhodium complexes. Amido-bridged compounds are relatively rareI3I, and to the best of our knowledge no related di(yamido)-bridged metal complexes
have been described.
We report here on the synthesis of a novel family of dinuclear amido complexes containing deprotonated 1,8diaminonaphthalene [(NH)2naphth]2Qas a bisdihaptobridging ligand. The isolated complexes 1 -3I4I were prepared as outlined in Scheme lIs1.
Received: June 27, 1984;
revised: August 27, 1984 [Z 902 IE]
German version: Angew. Chem. 96 (1984) 888
CAS Registry numbers:
3, 77357-86-9; 4, 92937-92-3; C N C ~ H I 931-53-3;
C , 7440-44-0; U, 7440-611.
[I] R. E. Cramer, R. B. Maynard, J. C. Paw, J. W. Gilje, Organometalh I
(1982) 869.
121 P. J. Fagan, J. M. Manriquez, T. J. Marks, V. W. Day, S. H. Vollmer, C.
S. Day, J. Am. Chem. SOC.102 (1980) 5393.
Angew. Chem. Int. Ed. Engl. 23 (1984) No. I 1
[*I Prof. Dr. L. A. Oro, Dr. M. J. Fernandez, Dipl.-Chem. J. Modrego
Departamento de Quimica Inorganica, Universidad de Zaragoza
50009 Zaragoza (Spain)
Dr. C. Foces-Foces, Dr. F. H. Can0
Departamento de Rayos-X, lnstituto Rocasolano, C.S.I.C.
Serrano 119, Madrid-6 (Spain)
0 Verlag Chernie GmbH, 0-6940 Weinheim, 1984
0570-0833/84/1111-0913 $ 02.50/0
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bond, insertion, double, uranium, carbon, isocyanides
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