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Difluoroarsoranes and Homologous Compounds RR2EF2 (E = As Sb Bi) by Oxidative Direct Fluorination of Organoarsanes Organostibanes and Organobismuthanes.

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Table 1. 'H-NMR data for the methyleneaziridines in [D6]-benzene.
Chemical shifts 6H
3-R'
4-R2
Cpd.
NCHs
3-H
Coupling constants IJI [Hz]
4-R3
2J
4J,,s
4Jtrms
( I i [h]
141
1.885
(21
2.39 [c]
0.95
(E)-(3)
2.26
1.75
(Z)-(3)
2.32
1.64
(CHsMi
0.07
H
4.559
H
4.54
(CH3)3Si
0.16
H
4.975
H
4.579
H
4.66
H
4.980
(CHaLSi
0.22
[a]
5Jt,.ns
~-
~~~
1.15
0.XS
1.32
< 0.1
1.11
1.35
1.90
ca. 0.1
-
-
1.1
-
-
0.7
-
ca. 0.1
[a] Estimated from the broadening of the signals of R2= H and the N-methyl groups.
[b] In CC14; the data of the ABX2 system were optimized using the program LAOCOON I11 [9].
[C] 4 J ( 3 . ~ , ~ . c ~ 3 ) =
HZ.
o.4
means of a program developed for the computation and drawing of mol fraction-time curves based on the solutions of the
differential equations corresponding to Scheme I[''',
we obtained the optimized constants listed in Table 2.
Table 2. Rate constants of the thermal reorganization of methyleneaziridine
( 2 ) according to Scheme 1 in [D6]benzene at 120.0"c.
Rate constants x lo5 [s']
k32
k24
Thermolysis of
k23
k34
~~
racemic ( 2 ) [a]
(-)-f2) P I
6.20
5.90
0.36
0.37
2.80
3.60
0.165
(0.02)
[a] One sample consisting of 0.063 ml of (2) in 0.520ml of [D6]benzene
0.010 benzene.
[b] Nine identical samples; [(-)-(,?)I =0.348 mOl/l.
+
Table 2 shows satisfactory agreement between the data
obtained in different ways. The trimethylsilyl group at the
double bond stabilizes ( 3 ) by 9.2 kJ/mol compared to (2).
From the rate constants it can be estimated that initially very
little (4) is formed (after 10h only 4%, total 30-35%) via
achiral (3) and that only negligible racemization of (-)-(2)
occurs in this way.
In the thermolysis of (-)-(2) the mol fractions x(i) after
10h were: x(2)=0.06, x(3)=0.56, x(4)=0.35 and x(secondary products of ( 4 ) ) = 0.03. But a405 had only decreased from
ao= -4.330" to -2.03'
b a t h length= 10cml. (4), and
thus also the optically active species, was selectively and completely removed without altering any of the other components
(IR and 'H-NMR spectra) by treating a sample of (-)-(2)
[x(4) =0.35, a405 = - 1.720'1, previously heated for 22.6 h,
with water. Consequently, only (4) was optically active and,
like the educt (-)-(2), levorotatory ; however, the enantiomer
excess of ( - ) - ( 4 ) could not be determined. Assuming that no
direct racernizati~n[~"'
of (-)-(2) takes place, the maximum
possible contribution to a405 arising from (-)-(2) can be
calculated according to q2,
= aoexp- (kZ3 k 2 4 ) t . Thus, for
( - ) - ( 4 ) a minimum rotation of a(4,=(a-q2,)/~(4)=
-5.5950.15" (from 5 measurements during the first 5 h,
[( - ) - ( 4 ) ] =0.348 mol/l in ED6]-benzene)is obtained, which is
considerably greater than the initial value a0 and therefore
indicative of a high degree of stereospecificity for the methyleneaziridine-cyclopropanimine rearrangement. Since on geometrical grounds retention at the migrating carbon atom,
C-3 in ( 2 ) , is highly improbable, inversion must have
occurred as in methylenecyclopropanes[zl.
+
Received: Bnuary 16, 1978 [Z 913 IE]
German version: Angew. Chem. 90, 224 (1978)
CAS Registry numbers:
(I), 25012-55-9; (-)-(2), 65665-40-9; (*)-(2), 65665-41-0; ( E ) - ( 3 ) , 6566542-1; (Z)-f3),65665-43-2; (E)-( - ) - ( 4 ) , 65665-44-3; (Z)-(- ) - ( 4 ) , 65665-45-4;
(+)-BDB, 26549-21-3
214
[l] 8. Schilling, J . P . Snyder, J. Am. Chem. SOC.97, 4422 (1975); E Jean,
A. Devaquet, ibid. 99, 1949 (1977); D. H . Hunter, S. K . Sim, R . P.
Steiner, Can. J. Chem. 55, 1229 (1977).
[ 2 ] W uon E. Doering, L. Birladeanu, Tetrahedron 29, 499 (1973); J . J .
Gajewski, S. K . Chou, J. Am. Chem. SOC.99, 5696 (1977); references
cited therein.
[3] a) D. B. Scloue, J. F . Pazos, R . L . Camp, F . D. Greene, J. Am. Chem.
SOC.92, 7488 (1970); b) M. Bertrand, J . P . Dulcere, G . Gil, Tetrahedron
Lett. 1977, 4403.
[4] H . Quast, W Rider, Angew. Chem. 85, 411 (1973); Angew. Chem.
Int. Ed. Engl. 12, 414 (1973).
[5] H . Quast, C . A . Weise Vklez, Angew. Chem. 86, 380 (1974); Angew.
Chem. Int. Ed. Engl. 13, 342 (1974).
161 D. Seebach, H . - 0 . Kalinowski, B. Bastani, G. Crass, H. Daum, H . Dorr,
N . P. DuPreez, 1.: Ehrig, K Langer, C . Niissler, H.-A. Oei, M . Schmidt,
Helv. Chim. Acta 60, 301 (1977).
[7] D. Seebach, K . - H . Geiss, J. Organomet. Chem. Libr. 1, 58 (1976); E
Izumi, A. Tai: Stereo-differentiating Reactions. Academic Press, New
York 1977, p. 115.
[S] H . L. Goering, J . N. Eikenberry, G . S. Koermer, C . J . Lattimer, J.
Am. Chem. SOC.96, 1493 (1974).
[9] W Rider, Dissertation, Universitat Wurzburg 1977.
[lo] The solutions quoted by E. S . Lewis and M. D. Johnson, J. Am. Chern.
SOC.82,5399 (1960), contain errors. We thank Dipl.-Math. S . Stindl and
DipLChem. M. Heuschmann for correcting these and Dr. W Rider for
writing the computer program.
Difluoroarsoranes and Homologous Compounds
R'R2EF2(E= As, Sb, Bi) by Oxidative Direct Fluorination of Organoarsanes, Organostibanes, and Organobismuthanes[**]
By Ingo Ruppert and Volker Bastian"]
Selective gas phase fluorinations of organoelement compounds are comparatively rarely exploited reactions in preparative chemistry[']. The observed oxidative fluorination of the
phosphorus in tertiary phosphanes['] without significant formation of side-products has now been extended for the first
time to its higher homologs.
Ph2E-R
+
Fz
ma3
(1)
E = A s : R = Me(a), Ph(b);
E = S b : R = Mefc), Phfd);
F
I
PhZE-R
I
F
(2)
E = B i : R = Ph(e)
[*] Dr. I. Ruppert ['I, Dr. V. Bastian
Anorganisch-chemisches Institut der Universitat
Gerhard-Domagk-Str. 1, D-5300 Bonn 1 (Germany)
[+]Author to whom correspondence should be addressed.
['*I Fluorinated Organoelements: Oxidative Liquid-Phase Direct Fluorination, Part 3.-Part 2 : I . Ruppert, Chem. Ber., in press.
Angew. Chem. Int. Ed. Engl. 17 (1978) No. 3
Surprisingly, despite the decreasing strength of the E-C
bond on going from P to Bi, not only the usual competition
from side-chain halogenation but even fluorinating cleavage
of the element-carbon bond can be largely suppressed under
the mild reaction conditions['].
Direct fluorination simplifies the conventional two-step
chlorine/fluorine exchange with metal fluorides [(2d)[4a],
(2e)[4b1]and is preparatively comparable with the fluorination
by sulfur tetrafl~oride[~']
previously described only for ( 2 b).
Its wide range of application can be illustrated using as example
the bis(difluoroarsoranes), a previously unknown class of substances.
In the case of ( 3 b ) and ( 3 c ) the reaction course is difficult
to monitor by 'H-NMR spectroscopy because of the high
proportion of phenyl or complex alkyl signals[6! Educt, difluoride intermediate['], and product, however, can easily be
detected by 'C{ 'HI-NMR spectroscopy; it not only guarantees recognition of the reaction end-point (shift parameters
in Table I), but also permits a simple structural diagnosis
based on fluorine-carbon coupling constants. Thus, the pseudotriplet of the a-alkyl C atom or the triplet of the cc,P-phenyl
C atoms and the quintet splitting of the monomethylene bridge
afford proof that two F atoms coordinate each As center.
This constitution also applies-at least in solution-in the
case of the methylated parent compound ( 4 a ) , though its
physical properties (higher melting point, lower solubility)
in comparison with (4 b d ) is surprising18].A fluorine exchange
caused by traces of hydrogen fluoride, which leads to merging
of the significant couplings to a broad singlet, can be suppressed by carrying out the measurement at low-temperature
or, more simply, by addition of a little triethylamine.
Attempts to fluorinate the arsanes (7) or (8) without rupturing the As-H or As-As bond have so far failed. Instead,
the trifluorodiphenylarsorane (9)[91was obtained from the hydride oia the isolable intermediate (8).
'
n = 1: R = Me(a), Et(b), i P r ( c ) , Ph(d);
n = 2: R = Ph(e);
n = 3: R = Ph(f)
Both phenylated and the more readily substituted alkylated
ditertiary bisarsanes ( 3 ) containing methyl bridges of varying
lengths can be converted in good yields into their tetrafluorides
by astream of fluorine diluted with an inert gas. The bisstibane
( 5 ) reacts similarly.
F
PhSb-CHZ-SbPhz
+
Experimental
A stream of diluted fluorine (max. 20ml F2 to 100ml Ar
per min) is passed into a magnetically stirred solution
of 30 mmol (I a-e), (3u-f) or (5)['01 in 150-200 ml anhydrous CFC13 (Solidex-glass flask with delivery tube and fitted
with a multiple-coil condenser, - 90°C circulatory cooling).
Only in the case of (3a-c) is the reaction solution additionally cooled to - 78°C. As shown by "C{ 'HJ-NMR monitoring, the reaction is complete only after addition of a 2to 2.5-fold excess of fluorine; however, excessive over-fluorination must be avoided in the preparation of the alkylated
bis(difluoroars0ranes) (4 a-c).
Workup of the products
depends upon their solubility in CFCI3: In the case of (46,
c ) the CFC13 is first removed and the remaining viscous
F
I
2 FZ + PhzSb-CHz-SbPhz
1-51
I
I
F
F
(61
Depending on the substrate reactivity and the solubility
of the partially fluorinated intermediates only part of the
fluorine passed into the system will actually be consumed.
On the other hand, uncontrolled over-fluorination attacks
the alkyl moiety non-specifi~ally[~];
hence, it is necessary to
use well defined amounts of fluorine.
Table 1. Preparative and NMR spectroscopic data [a] of the compounds synthesized.
Yield
[b]
c %I
M.p. r C ]
B.p. rC/torr]
19F-NMR [c]
I3C{'H}-NMR [c]
R=Alkyl
C-EFZ
(2a)
(26)
(2c)
(2d)
(2e)
75
93
74
88
78
96
135
92
116
158
-
78.0 q (7.0) [d]
s
-137.1 q (5.0)
-153.2 s
-161.3 s
22.7 t (21.5)
(4a)
(46)
82
82
40
73
88
63
91
166
106/0.001
118/0.001
134
144
108
153
- 46.3 s
- 12.2 s
- 89.0 s
- 74.1 t (10.0)
- 89.9 s
- 88.8 t (10.0)
- 127.7
23.0 pt (18.0)
32.1 pt (15.5)
42.9 pt (15.0)
(4c)
(4d)
(4e)
(4f)
(6)
C-CEF2
Bridge
F2E-C
- 88.9
11.0 t (16.7)
[fl
8.0 s
18.5 t
19.1 s
45.5
40.7
36.9
48.9
34.8
40.3
27.4
quint (22.0)
quint (22.5)
quint (23.4)
quint (25.6)
t t (20.7, 4.8)
t (18.0)
quint (21.0)
Phenyl
C'
C2
c3
c4
136.9 t (16.1)
137.4 t (18.3)
133.6 t (13.8)
134.3 t (15.4)
153.7 s [el
132.7 t (6.6)
133.0 t (7.0)
135.3 t (5.0)
135.4 t (4.9)
134.3 s
129.0 s
129.1 s
129.5 s
129.6 s
131.4 s
131.9 s
131.9 s
132.2 s
132.2 s
131.9 s
133.3 t
133.4 t
133.3 t
135.1 t
128.9 s
129.1 s
129.0 s
129.6 s
132.0 s
132.1 s
131.9 s
132.3 s
136.7 t
135.8 t
136.3 t
134.1 t
(15.5)
(16.0)
(15.0)
(13.5)
(7.8)
(7.5)
(6.0)
(4.5)
[a] The 19F- (Varian A 56/60, 56,4 MHz, CFCI3 int.) and 13C{1H}-NMRspectra (Bruker WP60, 15.08 MHz, TMS int.) were recorded in concentrated CDCI,
solution. The less informative 'H-NMR spectra, which show '3C-analogous fluorine couplings in the alkyl part, are available from the author on request.
[b] Analytically pure product; with the exception of (2e) all reactions proceed almost quantitatively ("C-NMR).
[c] S (J [Hz]). [d] Superposed 'H-13F
coupling of the alkyl(ene) protons in Hz; the fluorine signals given as singlets (s) are broadened by nuclear quadrupole and complex proton interaction.
[el Despite high resolution no triplet observable. [f] Pseudotriplet (pt) due to 'J(F-As-C)
and 'J(F-AsCAs-C);
first order coupling constant.
Angew. Chem. Int. Ed. Engl. 17 (1978) N o . 3
215
residue is distilled in vucuo (mercury vapor jet pump). In
the case of (2a, c, d) the solution is first filtered free of
small amounts of solid byproducts, the CFCI3 removed, and
the residue then recrystallized from hot n-hexane [(Za,
d)] or frozen out from n-pentane [(2c)]. In all the remaining
cases the almost colorless suspension is first evaporated down
in vacuo and the residue then recrystallized from boiling n-heptane [ ( 2 b , e ) , (4d-f)],
benzene [(4a)], or cyclohexane [(6)]
under an inert gas.
Received: January 26, 1978 [Z 916 IE]
German version: Angew. Chem. 90, 226 (1978)
CAS Registry numbers:
( 1 a ) , 945-48-2; ( 1 b), 603-32-7; ( I c ) , 30982-88-8; ( 1 d), 603-36-1; ( 1 e ) . 60333-8; ( 2 a ) , 33156-92-2; ( 2 b ) , 3824-71-3; (2c), 33756-92-2; ( 2 d ) , 373-84-2;
( 2 e ) , 2023-48-5; ( 3 a ) , 30043-88-0; ( 3 b ) , 65718-97-0; ( 3 c ) , 65718-96-9;
( 3 d ) , 21892-63-7; ( 3 e ) , 4431-24-7; (3f). 19364-57-9; ( 4 a ) , 65118-95-8;
(4b), 65718-94-7; ( 4 c ) , 65718-93-6; (4d), 65718-92-5; (4e). 65118-91-4;
(4f), 65718-90-3; IS), 30224-53-4; ( 6 ) . 65718-89-0; ( 7 ) , 829-83-4; ( a ) , 221536-3; ( 9 ) , 65794-25-4; '3C, 14762-14-4
On the problems of elemental fluorination cf. E . K . S . Liu,R . J . Lagow,
J. Am. Chem. Soc. 98, 8270 (1976).
[2] 1. Ruppert, !l Bastian, Angew. Chem. 89, 763 (1977); Angew. Chem.
[I]
Int. Ed. Engl. 16, 718 (1977).
[3] In contrast, alkylarsanes are already cleaved at moderate temperatures
by C12,Br, or 12; this halodemetalation of the alkyl moiety has recently
been developed into a new synthetic method: 7: Kauffmann, H . Fischer,
A . Woltermann, Angew. Chem. 89, 52 (1977); Angew. Chem. Int. Ed.
Engl. 16, 53 (1977).
[4] a) G . 0.Doak, G . G . Long, L. D. Freedman, J. Organomet. Chem.
4, 82 (1965); b) F . Challenger, J . F. Wilkinson, J. Chem. SOC. 121,
91 (1922); c) W C. Smith, J. Am. Chem. SOC.82, 6176 (1960).
[5] Accordingly, in the spectra of (4a-c) higher fragmentations of low
intensity are also observed which derive from molecular ions M'
n 18
( = M i - n H + n F ; n= 1,2).
[6] These are caused by additional 'H-'H coupling of diastereotopic
methylene-[(3b)] and methyl protons [ ( 3 c ) ] .
[7] Apart from the expected I3C{'H)-NMR spectrum, with a triplet for
the a-C atoms of the difluoroarsorane moiety with slight deshielding
of the dialkylarsane moiety, the difluoride intermediate can be recognized
by its "F-NMR signal, which is shifted upfield by about 5 ppm compared
to that in (4a-d).
[8] This finding points t o an isomeric fluoroarsonium trifluoroarsenate
structure in the solid state.
[9] At room temperature ( 9 ) shows a trigonal-bipyramidal array of differently fixed fluorine atoms: I9F-NMR (CDC13): 6 = -72.3 [d, *J(F,Fa)= 73 Hz, F,], -94.9 [t. Fe], as previously found by E . L. Muetterties,
W Mahler, K . J . Packer, R . Schmutzler, Inorg. Chem. 3, 1298 (1964).
Thus, the more recent findings on a non-freezable ligand exchange
[ L . B. Littlefield, G . 0. Doak, J. Am. Chem. SOC. 98, 7881 (1976)]
could not be confirmed.
[lo] Preparation of starting compounds: ( l a ) : G . J . Burrows, E. E. Turner,
J. Chem. SOC.1920, 1373; ( 1 b): R . L. Shriner, C. N. WOK Org. Synth.
Coll. Vol. I Y 910 (1963); ( l c ) . as in K . Bowden, E . A. Braude, J.
Chem. SOC.1952, 1068 [b.p.o,oo, 98"CI; ( I d , e ) : H . E. Ramsden, Brit.
Pat. 824944 (1959), Metal and Thermit Corp. [Chem. Abstr. 54, P
17238 d (196O)l; ( 3 a-d): Grignard reaction of methylenebis(dich1oroarsane) [ F . Popp, Chem. Ber. 82, 152 (1949)] in ether (RBr:
( C I ~ A S ) ~ C= H
5 :~1) [ ( 3 a ) : b.p.,, 56°C (64 ",! yield), (3b): b.p.,, 117°C
(85 %), ( 3 ~ ) b.p.0.0~
'
74°C (63%); ( 3 d ) . A. J . Titor, 5. B. Lewin,
Chem. Abstr. 49,4504h (1955)l; (3e,f): A. Tzschach, W Lange, Chem.
Ber. 95, 1360 (1962); (5). Y Matsumura, R . Okawara, J. Organomet.
Chem. 25, 439 (1970).
+
ABSTRACTS
esters of chlorothiocarbonic acid. The CSe ligand can be
similarly inserted. CS can also function as bridge ligand;
the corresponding CSe complexes have so far not been
reported. Only very few complexes containing multiple CS
or CSe ligands are known, in contrast to CO complexes.
[Transition-Metal Thiocarbonyls and Selenocarbonyls. Acc.
Chem. Res. 10, 359-365 (1977); 73 references]
[Rd loo0 IE]
The structure and properties of amorphous ("glassy") metals
and alloys are reviewed in an article by P. Chaudhari and
D. Turnbull. Certain metals and alloys can be put into the
glassy form by quenching the melt to T<T,, condensation
of the gas or diluted solution onto a substrate kept at T< Tg,
or radiation of the crystalline solid at T< Tg (q=glass transition temperature). The electrical, magnetic, and mechanical
properties as well as the superconductivity of various metallic
glasses including, inter alia, those of Ge, Zr, Hf, Ir, Os, Ru,
and of C o p , Cu/Cr, Ni/Nb, and Gd/Co alloys are discussed
and their technical potential outlined. [Structure and Properties of Metallic Glasses. Science 199, 11-21 (1978); 114 references]
[Rd 998 IE]
Transition-metal thiocarbonyls and selenocarbonyls form the
subject of a review article by I . S. Butler. Compounds containing the CS ligand can be obtained by direct reaction with
CS2 (example: R u B ~ ~ ( P P ~ ~ ) ~ . MRuBr3(CSMPPh3)),
~OH
reaction with CS2/"Ph3 ([IrC1(C8H12)]2 + transIrCI(CS)(PPh3)2),treatment with thiophosgene, or with 0-
-
216
Transfer RNA is the topic to which a complete issue of
Accounts of Chemical Research has been devoted. After an
introduction by A . Rich and P. R. Schimmel (pp. 385-387;
24 references), A . Rich reviews the three-dimensional structure
and biological function of tRNA (pp. 388-396; 29 references).
B. R. Reid and R. E. Hurd deal with NMR investigations
(pp. 396-402; 34 references) and J . A . McCloskey and S.
Nishimura with modified nucleosides in tRNA (pp. 403-410;
101 references). P. R. Schimmel reports on the recognition
process between tRNA and aminoacyl-tRNA synthetase (pp.
411-418; 49 references) and W H . McClain on the terminal
seven steps of the biosynthetic pathway leading from DNA
to tRNA (pp. 418-425; 29 references). [Acc. Chem. Res.
10, No. 11 (1977)l
[Rd 1 IE]
Carbene-carbene rearrangements in solution are reviewed by
W M . Jones. In such reactions the carbene initially formed
is first converted into a second carbene, which then yields
products containing only tetravalent carbon. In rearrangements of Type I (only these are described) the "divalency"
formally shifts from the carbene carbon to another carbon
atom. Rearrangements of Type I1 are limited (with one excepAngew. Chem. I n t . Ed. Engl. 17 (1978) No. 3
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rr2ef2, homologous, compounds, organoarsanes, organobismuthanes, difluoroarsoranes, direct, oxidative, organostibanes, fluorination
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