close

Вход

Забыли?

вход по аккаунту

?

Carbene Addition to Dicarbonyl(-cyclopentadienyl)cobalt.

код для вставкиСкачать
Catalyzed Rearrangement of Nitrile Oxides to Isocyanates['*I
By Georg Trickes and Herbert Meierp]
The rearrangement of nitrile oxides ( I ) to isocyanates (2)
is of particular interest because of the simultaneous shift of
two ligands along a CN unit. This long-known reaction[']
has recently been studied in some detail by Grundmann et
a/.[". Use of the thermal rearrangement ( 1 ) -+ (2) is severely
restricted by the competing dimerization of ( I ) to the furoxanes (3).
Identification of (2), ( 4 ) , ( 5 ) , and (7) utilized the usual
analytical and spectroscopic methods (in some cases in comparison with authentic samples).
Received: June 21, 1977 [Z 766 IE]
German version: Angew. Chem. 89,562 ( 1 977)
CAS Registry numbers:
( I a ) . 873-67-6; (1 b), 15500-74-0; (1 c ) , 15500-73-9; (1 d ) , 2574-03-0; ( Z a ) ,
103-71-9; (2b), 10412-1; ( 2 ~ ) 5416-93-3;
.
( Z d ) , 100-28-7; ( 4 ~ ) 19279-25-5;
.
(4b), 63324-79-8; ( 4 c ) , 19279-26-6; ( 4 d ) , 19279-27-7; ( S a ) , 495-18-1; (Sh).
1613-88-3; (Sc), 10507-69-4; ( S d ) , 1613-76-9; (6a), 62-53-3; (6b), 106-47-8;
(6c), 104-94-9; (6d), 100-01-6; (7a), 102-07-8; (7b), 1219-99-4; 1 7 c ) , 122744-7; (7d), 587-90-6
[t] S . Gabriel, M. Hoppe, Ber. Dtsch. Chem. Ges. 19, 1145 (1886); H . Wieland,
ibid. 42, 803, 4207 (1909).
[2] C. Grundmann, J . M . Dean, Angew. Chem. 76,682 (1964); Angew. Chem.
Int. Ed. Engl. 3, 585 (1964); C. Grundmann, P . Kochs, ibid. 82, 637
(1970) and 9, 635 (1970), respectively; C . Grundmann, P . Kochs, J . R .
Boal, Justus Liebigs Ann. Chem. 761, 162 (1972).
131 H . Meier, G . Trickes, H . - P . Braun, Tetrahedron Lett. 1976, 171 ; G . Trickes,
H . - P . Braun, H . Meier, Justus Liebigs Ann. Chem. 1977, in press.
141 Cf. J . Sauer, K . K . Mayer, Tetrahedron Lett. 1968,319; E. Eibler, J . Sauer,
ibid. 1974, 2565.
[5] I. L . Knunyanrs, E. G. Bykhouskaya, V. N . Frosin, Dokl. Akad. Nauk
SSSR 127, 337 (1959); H . Boeshagen, DBP 1157231 (1963).
While studying the photochemistry of 1,2,3-thiadiazole 1,1,2trioxide~[~I
we discovered a catalytic process permitting the
rearrangement ( 1 ) - ( 2 ) to be performed under such mild
conditions that dimerization is avoided. A suitable catalyst
is sulfur dioxide, which participates in the reaction as a dipolarophile.
(51
b
(2) directly f r o m ( ] ) 7 0 - 9 5 7 0
(7) directly from(1) 6 8 - 9 3 7 0
(5) directly f r o m ( ] ) 8 1 - 9 4 7 0
(7) f r o m (2)
(Sj from(,?/
78-98%
98%
In this way the rearrangement of nitrile oxides (1) to the
isocyanates (2) in excellent yields can be accomplished directly in boiling anhydrous benzene; however, 1,3,2,4-dioxathiazole 2-oxides ( 4 ) can also be isolated as intermediates''].
Compounds ( 4 ) are extremely sensitive to moisture and quantitatively afford hydroxamic acids ( 5 ) on treatment with water
at room temperature. The first published synthesis of (4)r5I
utilized the reverse reaction of ( 5 ) with sulfinyl chloride.
If work-up is carried out in aqueous medium at 70--80"C,
compounds (2) yield the symmetrical urea derivatives (7)
via the amines (6).
[*] Prof. Dr. H. Meier, Dipl.-Chem. G. Trickes
Institut fur Organische Chemie der Universitat
Auf der Morgenstelle 1 X, D-7400 Tubingen 1 (Germany)
[**I This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie.
Anyew. Ckem. lilt.
Ed. Engl. 16 (19771 N o . 8
Carbene Addition to Dicarbonyl(q-cyclopentadieny1)cobalt['l
By Manfred L. Ziegler, Klaus Weidenhammer, and Wolfgang
A . Herrmann"]
Oxidative addition with elimination of CO occupies a special
place in the chemistry of dicarbonyl(q -cyclopentadienyl)cobalt
(l)'']. The reason for this is the low coordination number
of the metal atom, which facilitates nucleophilic attack at
the center of the molecule.
While aliphatic diazo compounds readily react with ( I )
on heating to give dinuclear p-methylene cobalt c o m p l e ~ e s ~ ~ l ,
we have now also been able to synthesize mononuclear derivatives--via a photochemical route starting from the dialkyl
diazomalonates ( 2 a ) and ( 2 b ) . The green crystalline compounds (3 a) and (3 b), obtained in ca. 60 % yield, are moderately air-stable, diamagnetic, and readily dissolve in strongly
polar solvents. According to total elemental analysis and osmometricmolecular weight determinations they have the empirical
formulas C12HllCo06and CI4Hl5C0O6,respectively. Since
the mass spectra show no molecular ions, and the IR, 'H-NMR
and I3C-NMR spectra (Table 1 ) provide only proof of the
structure (q 5-C5H5)Co(CO)Lbut no conclusive evidence
about the constitution of the ligand L, we have carried out
a crystal structure analysis on the ethyl derivative ( 3 b)141.
The presence of a five-membered metallacycle proves that
the reaction
(1)
(2)
( a ) : R = CH,
( b ) : R = CZHS
131
[*] Dr. W. A. Herrmann
Chemisches lnstitut der Universitat
UniversitatsstraDe 31, D-8400 Regeushurg 1 (Germany)
Prof. Dr. M. L. Ziegler, Dip].-Chem. K. Weidenhammer
Anorganisch-chemisches Institut der Universitat
I m Neuenheimer Feld 270, D-6900 Heidelberg 1 (Germany)
555
proceeds via the unusual 1,3-addition of bis(alkoxycarbony1)carbene : C(COzR), to the substrate ( 1 ). Linking of a carbene
carbonyl oxygen atom to the metal atom and conversion
of an M-COgroup into an M-Acyl function increases
the coordination number of the central metal atom, which
is finally located in a distorted tetrahedral environment. To
our knowledge [2 31-carbene additions of this type have
hitherto not been observed in organometallic chemistry.
+
Experimental['] :
Fig. 1. ORTEP diagram of the carbene adduct ( 3 b ) .
Bond lengths [pm]
Co-C6
164.3(20)
Co-02
192.2(12)
CO-C9
205.8(14)
02-0
129.1(I 9)
c7-C8
139.5(16)
C7-04
131.6(21)
CX-C9
144.7(26)
C8-CI2
146.0(20)
CY-03
116.3(18)
["I
Angle
02-CO-CY
C0-02-C7
02-C7-C8
C7-C8-C9
C8-C9-Co
85.02(58)
112.64(85)
121.25(81)
115.3(1.3)
105.59(82)
Table I . Spectroscopic data of the carbene addition products ( 3 a ) and
A solution of ( I ) (3.60g, 20mmol) and ( 2 a ) (3.79g,
24 mmol) or (2 b ) (4.50g, 24 mmol) in tetrahydrofuran (200 ml)
is irradiated (Hg high-pressure lamp T Q 150)for 10 h at - 25 "C
in a pyrex immersion-lamp apparatus furnished with internal
and external cooling. The green reaction solution is concentrated by evaporation under high-vacuum at +20"C and
then purified by column chromatography (Kieselgel60, Merck
7734; Act. 11-111; 4 8 x 2 c m ; 10°C). The carbene adducts
( 3 a ) and (3 b), respectively, are eluted with acetone as rapidly
migrating deep-green zones. The oily residue remaining after
evaporation of the eluate is crystallized from ether/CH2C12
(1O:l) at -35°C. The dark green crystals have a metallic
luster. After washing them with 3 x IOml ether they are
recoverable in analytically pure form. ( 3 a ) : 3.60g (58%);
m.p. 145-149°C. (3b)r4.13g(61%);m.p. 118 to 119°C.
(3bJ
IR [vCO in cm-'1: 2052 vs; 1720 s,
1690 s-vs (sh, br) [CH2C12]
2032 VS;1694 vs, 1683 vs (sh)
W r I
'H-NMR [a]: C5H5 '4.75 (S), CH,
'6.25 (3) and '6.38 (3) [CD2C12]
"C-NMR [b]: C5H592.61, CH3
50.63, MCO ca. 200.0, remaining C :
161.50, 183.79.205.63. 214.08
Received: June 10, 1977 [Z 758 IE]
German version: Angew. Chem. 89, 557 (1977)
2042 vs: 1720 s (sh), 1680 s (sh, br)
[CH2C121
2043 vs; 1712 vs (sh) [KBr]
CAS Registry numbers:
( I ) , 12078-23-8: ( 2 a ) . 6773-29-1; ( 2 6 1 , 5256-74-6; ( 3 a ) , 63301-85-9; ( 3 6 ) ,
63301-86-0.
Complex Chemistry of Reactive Organic Compounds, Part 19. Thls
work was supported by the Deutsche F0rschungsgemeinschaft.-Part
18: W A. Herrmann, M . Huber, J. Organomet. Chem., in press.
121 J . P . Cullman, W R. Rooper, Adv. Organomet. Chem. 7, 53 (1968);
R . Kummer, W A . G . Graham, Inorg. Chem. 7, 523 (1968).
[3] W A. Herrmann, Chem. Ber., in press.
[4] Crystal data: monoclinic, space group C:h-P21/~; a = 1124.6(4),
b=799.7(5),r= 1900.8(6)pm,p = 119.5q2)"; Z = 4 . 1393 independent nonzero reflections were measured with a n automatic Siemens single crystal
diffractometer and corrected in the usual way ( R= 7.4 %).
[S] All operations must becarried o u t ~nthe absenceo102 and H,O.-Experimental and spectroscopic details: W A . Hewmanil, M . L. Ziegler, K .
Weidmhammer, J . Organomet. Chem., in preparation.
[I]
C5H5 '4.83 ( 5 ) . C H 2 45.86 (4), CH3
%.76 and '8.78 (tot. int. 6) [CDCl,];
90-MHa FT spectrum
C 5 H 5 '5.50 (5), C H 2 45.72 and 46.05
(tot. int. 4), CH3 '8.80 and 39.01(tot.
iut. 6) [C6D6]
C5H592.61, CHI 63.04 and 59.21,
CHa 14.69, M C O ca. 200.5, remaining C: 161.05, 183.60, 205.43
[a] rvalues;TMS int.; +33"C. [b] 6 values; 22.63 MHz; TMS int.: +32"C;
ca. 1.5 M solution in CD2C12;"remaining C": assignments uncertain.
ABSTRACTS
O
HO
AN
OH
(I), X = R = H
Syntheses and rearrangements of Ssubstituted pyrimidine
nucleosides and nucleotides are reviewed in an article by 7: K .
Bradshaw and D. W Hutchinson with particular emphasis on
the derivatives of uridine ( I ) and cytidine (2). X in ( I ) can,
for example, be CI, Br, NO, or C H 2 0 H , while with ( I ) ,
R = P03H or (P03H)2H, 5-hydroxy derivatives are also
obtained. Halogen derivatives of ( 2 ) , R = H, are also known;
556
O
I
Hb
a
N
l
OH
(2), X = R = H
5-hydroxymethyl compounds are not formed. In all syntheses
the result strongly depends upon substitution pattern.
Mechanisms are suggested for substitution at C-5 and for
exchange reactions. Biochemically interesting in this connection is the mode of action of the thymidylate synthetase.
[5-Substituted Pyrimidine Nucleosides and Nucleotides.
Chem. SOC.Rev. 6, 43-62 (1977); 1 10 references]
[Rd 956 IE-F]
Angew. Chem i n r Ed Engl. 16 (1977) Nu. 8
Документ
Категория
Без категории
Просмотров
0
Размер файла
227 Кб
Теги
carbene, additional, cobalt, cyclopentadienyl, dicarbonyl
1/--страниц
Пожаловаться на содержимое документа