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Epoxidation of Olefins with Elemental Fluorine in WaterAcetonitrile Mixtures.

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balt(0) at the center and a porphinate radical anion with
d'-cobalt(i) as central atom:
1131 S. Gambarotta, F. Arena, C. Floriani, P. F. Zanazzi, J . Am. Chem. SOC.
104 (1982) 5082.
[I41 G. Fachinetti, C. Floriani, P. F. Zanazzi, A. R. Zanzari, Inorq. Chem 18
(1979) 3469.
[I51 S. Gambarotta, F. Arena, C. Floriani, A. Gaetani-Manfredotti, J . Chem.
SOC.Chem. Commun. 1982, 835.
For final confirmation of the radical anion character of
complex 2 , further studies are necessary. Present considerations, however, suggest that the cobalt(o) designation
should be used as a label of convenience only. The above
Epoxidation of Olefins with Elemental Fluorine in
findings closely parallel those in iron chemistry concerning
Water/Acetonitrile Mixtures
the two reduced forms [Fe(TPP)]" and [Fe(TPP)]'3,1'1
By Shlomo Rozen* and Michael Brand
though a significant difference exists between the stability
of the reduced form as a function of the meta1.1'.3.71A sigIn the last few years we have shown that elemental fluonificant aspect of these structures which can be deduced
rine, which, since its discovery one-hundred years ago, had
from the structural determinations of the doubly reduced
been in a state of hibernation as far as organic chemistry
species [M(TPP)]" [ M = Fe, Co], is that the reduction
was concerned, can in fact be a versatile fluorinating reaproducts occur in tightly ion-paired forms in the solid
gent."-'] We report here a general reaction of F2 that leads,
state. Current efforts are aimed at finding a relationship
in contrast, to fluorine-free derivatives, namely, the facile
between the structure in the solid state and in solution.
synthesis of epoxides from olefins using fluorine in water/
Such ion-pairs have already been found to exist in salenacetonitrile mixtures.
type compounds (salen = N , N'-ethylenebis(sa1icylideneamThere are several methods for the synthesis of epoxides,
inato)) both in solution1'2.'31and in the solid ~ t a t e . ~ ' , ~ . ' ~ , ' including
~~
the reaction of olefins with peracids, H202, or
In these complexes, the simultaneous presence of acidic
XOH (X=Cl, Br; subsequent elimination of HX).@' Most
(alkali cation) and basic (cobalt) sites close together in the
of these reactions, however, proceed slowly, need strongly
same molecular structure is responsible for the so-called
basic or acidic medium, and often afford unsatisfactory
'bifunctional' fixation of CO, and other reaction^,"^,'^'
y ie 1d s.
which are not observed in the case of such complexes with
When dilute fluorine (10% in N2) is passed through dry
only a single reactive site.
acetonitrile or distilled water at O T , only a small amount
Received: December 10, 1985;
of oxidizing agent is produced, which is inactive toward
revised: March 14, 1985 [Z 1577 IE]
olefins. When a similar N2/F2 mixture is passed through a
German version: Anqew Chem. 98 (1986) 553
well-agitated solution containing 400 rnL of acetonitrile
and 20 mL of distilled water, however, an oxidizing solution is obtained. When it was added to cis-cyclooctene 1 in
[ I ] H . W. Whitlock, B. K. Bower, Tetrahedron Lert. 1965, 4827; H. KobaCHCI3 at -15"C, reaction was complete within 1 min.
yashi, T.Hara, Y . Kaizu, Bull. Chem. SOC.Jpn. 45 (1972) 2148; D. A.
Clarke, D. Dolphin, R. Grigg, A. W. Johnson, H. A. Pinnock, J . Chem.
After neutralizing the reaction mixture with NaHC03, we
Soc. C 1968. 881; M. Momenteau, M. Fournier, M. Rougee, J. Chim.
were able to isolate cis-epoxycyclooctane 2 in 85% yield.
Phys. Phys.-Chim. Biol 67 (1970) 926.
The epoxidation is stereospecific, as is evident from the
[21 For related supernucleophilic systems see: U. Eckert, 1. Ugi, Angew.
conversion of trans- and cis-stilbene, 3 and 5, respectively,
Chem. 88(1976)717; Angew. Chem. Int. Ed. Engl. 15(1976)681: ibid.87
(1975) 847 a n d 14 (1975) 825.
into frans- and cis-2,3-diphenyloxirane, 4 and 6, respec[ 3 ] P. Doppelt, J. Fischer, R. Weiss, Inorg. Chem. 23 (1984) 2958 and referti~e1y.I'~Both reactions were complete within one minute
ences therein. The 2,2,2-crypt ligand is 4,7,13,16,21,24-hexaoxa-l,lO-diin a yield of over 80%.
azabic~clo[8.8.8]hexacosane.
141 The solid is highly crystalline and homogeneous. The quoted yield can
be improved if a less crystalline material is desired. The IR spectrum is
significantly different from those of the three complexes 1, 2, 3 and can
he used for identification. Since 2 is extremely air-sensitive, particularly
in dilute solutions, a n electronic spectrum of 2 in which oxidized products are not present could not be recorded.
[S] The number of thf molecules in 3 was deduced from the ' H - N M R spectrum.
[6] Space group Pi, a = 13.172(3), b = l1.905(2), c = l1.293(2)
a = 110.29(2), /3=113.74(2), y=77.49(1)"; V=1514.3(6)A3; Z = l ;
p(MoK,)=3.48 c m - ' . 5314 unique reflections [1>3o(I), 6 < 2 @ < 5 0 " ,
were measured on a Philips PW 1100 diffractometi,(MoK,)=0.71069
er. The structure was solved by Patterson and Fourier syntheses and refined anisotropically by full-matrix least-squares t o R = 0.055. Further
details of the crystal structure investigation are available on request
from the Fachinformationszentrum Energie, Physik, Mathematik
GmbH, D-75 14 Eggenstein-Leopoldshafen2, on quoting the depository
number CSD-51788,the names of the authors, and the full citation of
the journal.
171 T. Mashiko, C. A. Reed, K. J. Haller, W. R. Scheidt, Inorg. Chem. 23
(1984) 3192; C. A. Reed, Adu. Chem. Ser. 201 (1984) 333.
181 D. Moras, R. Weiss, Acra Cryslallogr. Sect. B29 (1973) 396; R. G. Teller,
R. G. Finke, J. P. Collman, H. B. Chin, R. Bau, J. Am. Chem. Soc. 99
(1977) 1104.
[9] J. H . Noordik, H. M. Doesburg, P. A. Prick, Acta Crystollogr. Sect. 8 3 7
(1981)1659: N. Bresciani-Pahor, M. Calligaris, P. Delise, G. Nardin, L.
Randaccio, E. Zotti, G . Fachinetti, C. Floriani, J . Chem. SOC. Dalton
Tram. 1976. 2310.
[lo] W. R. Scheidt, J . Am. Chem. SOC.96 (1974) 84.
[ I I ] E. B. Fleischer, C K. Miller, L. E. Webb, J Am. Chem. Soc. 86 (1964)
2342.
1121 A. Giacomelli, T. Rotunno, L. Senatore, Inorg. Chem. 24 (1985) 1303.
A,
A]
554
0 VCH Verlagsgesellschaft mbH. 0-6940 Weinheim, 1986
5
H\
/IT
/c=c\
Ph
Ph
-
0
H%,/ \
3
Ph
'
P
h
,c-C'
6
Terminal olefins are usually more sensitive toward
strong oxidizing agents. However, even such olefins react
[*] Prof. Dr. S. Rozen, M. Brand
[**I
School of Chemistry, Raymond and Beverly Sackler Faculty
of Exact Sciences, Tel-Aviv University
Tel-Aviv 69978 (Israel)
This work was supported by the Fund for Basic Research of the Israel
Academy of Science and Humanities.
0570-0833/86/0606-0554 $ 02.50/0
Angew. Chem Ini. Ed. Enql. 25 (1986) N o . 6
practically instantaneously to give the corresponding oxiranes in high yields: for example, 1-dodecene 7 was converted into 8 in a yield of over 90%.
Conjugated enones, which are much more resistant to
epoxidation, undergo oxidation if the ratio of oxidizing
agent to alkene is increased from 1.2: 1 to 2.5: 1. Thus,
ethyl cinnamate 9 was converted into the corresponding
epoxide
within one minute in 80% yield. Benzylideneacetone 11 and progesterone 13 underwent rapid epoxidation to give 12 (m.p.=45°C1"1) and 14 (m.p.= 177'C1'']),
respectively, in yields of 85% and 80%.
PhC H- C HC O OE t
11
Earlier we reported the conversion of the binuclear molybdenum complex 1 into the ligand-stabilized alkylrnoWe discuss here the
lybdenum complexes 2 [Eq.
reactions of 1 with Grignard reagents in the absence of
stabilizing-ligands [Eq. (b)].
10
-
&
13 0
By Reinhard Benn, Sigrid Holle, Peter W. Jolly,*
Richard Mynott, and Carlos C . Romiio
+ PhC€T-CHCOOEt
9
PhC t I = C H C O C H ,
-
IMoR(q3-C3H& R=Alkyl: Alkylmolybdenum
Complexes with Agostic C-H Mo Bond**
L
O
/\
PhCH-CHCOCH,
12
1
+-
2iPrMgCl
2[(q3-C3H&Mo-H-CH2-kHCH,I
(b)
3
0&14 "+O
Acetonitrile is known to act as a carrier for an oxidizing
agent. It reacts with H 2 0 2 to form peroxyimidic acid 15,
an intermediate that has not been isolated, but which
reacts with some olefins to form e p o ~ i d e s .This
~ ' ~ ~epoxidation reaction, however, usually requires several hours at elevated temperatures, and electron-poor olefins such as
enones d o not react.
Treatment of 1 with isopropylmagnesium chloride in
ether at -78°C results in the formation of a yellow compound [ M ~ i P r ( q ~ - c ~ 3,
H ~which
) ~ ] decomposes in solution
above ca. - 10°C. The 'H-NMR spectra at various temperatures indicate that 3 contains an alkyl group having an
agostic hydrogen atom (Fig. l):I3] at - 120°C the three H
atoms of one of the methyl groups are magnetically inequivalent with the agostic H atom absorbing at 6= - 8.43. At
higher temperatures exchange of these protons occurs and
at - 50°C only one signal is observed (S= - 2.90). The second methyl group is not involved in this process (the associated doublet is sharp at all temperatures). Furthermore,
there is no evidence for transfer of the agostic H atom to
the metal-at least within the temperature range studied
(-30°C to - 120°C).
Since no oxidizing solutions are formed with fluorine
unless both CH3CN and H 2 0 are present, CH3CN must be
essential for the formation of the oxidizing agent. A crucial
step is presumably the formation of hypofluorous acid,
HOF,1'41which then reacts with CH3CN. The F2/CH3CN/
H 2 0 system offers promise as a useful method for fast,
low-temperature, high-yield epoxidations.
Received: January 21, 1986;
revised: March 13, 1986 [Z 1631 IE]
German version: Angew. Chem. 98 (1986) 565
[I] C . Gal, S. Rozen, Tetrahedron Lett. 26 (1985) 2793.
I21 S. Rozen, 0. Lerman, J. Org. Chem. 45 (1980) 672.
131 0. Lerman, S. Rozen, J . Org. Chem. 45 (1980) 4122; D. F. Persico, G. E.
Gerhardt, R. J. Lagow, J . Am. Chem. Soc. 107 (1985) 1197.
141 J. L. Adcock, M. L. Robin, J. Org. Chem. 49 (1984) 1442.
[S] 0. Lerman, Y. Tor, D Hebel, S. Rozen, J . Org. Chem. 49 (1984) 806.
161 S. Rozen, M. Brand, Synthesis 1985, 665.
171 S. Rozen, M. Brand, J . Org. Chem. SO (1985) 3342.
181 A. Y. Zapevalov, T. 1. Filyakova, I. P. Kolenko, N. V. Peschanskii, M. 1.
Kodess, Zh. Org. Khim. 20 (1984) 2267.
[9] G. Ceccarelly, G . Berti, G. Lippi, 9. Macchia, Org. Magn. Reson. 2
(1970) 379.
[lo] J. Baldas, Q . N. Parter, Aust. J . Chem. 20 (1967) 2655.
[ I I] R. D. Temple, J . Urg. Chem. 35 (1970) 1275.
[I21 H. B. Henbest, W. R. Jackson, J . Chem. Soe. C 1967. 2459.
1131 R. D. Bach, J. W. Knight, Org. Synrh. 60 (1981) 63, and references cited
therein.
[I41 E. H. Appelman, R. C . Thompson, J . Am. Chem. Soc. 106 (1984) 4167.
Angew
C'hem lnr Ed. Engl Z ( 1 9 8 6 ) No. 6
_2
-
~
0
2
-4
--
I
7
~
-7
-6
8
-6
Fig I Part of the ' H NMR spectrum of 3 (400 MHz, [D,]toluene)
- 120°C (below) and -50°C (above)
dt
[*] Dr. P. W. Jolly, Priv.-Doz. Dr. R. Benn, S . Holle,
['I
[**I
Dr. R. Mynott, Prof. Dr. C . C. Romio ['I
Max-Planck-Institut fur Kohlenforschung
Postfach 10 13 53, D-4330 Miilheim a. d. Ruhr (FRG)
Present address: Instituto Superior Tecnico
Lissabon (Portugal)
C. C. R. thanks the Alexander von Humboldt Stiftung for a stipendium.
0 VCH Verlugsgesellschafr mbH. 0 - 6 9 4 0 Weinheim. 1986
OS70-0833/86/0606-0855 S 02.50/0
555
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mixtures, olefin, elementary, epoxidation, fluorine, wateracetonitrile
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