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Chain-Lengthening Difunctionalization of Grignard Compounds by Reaction with Ketenylidenetriphenylphosphorane.

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Table I . Degree of double deuteration [I21 and silylation of the bicyclobutanrs la-6a as a measure of the lithiability of the two bridgeheads with 2.0
mole equivalents of nBuLi in ether at 20°C.
Chain-Lengthening Difunctionalization of
Grignard Compounds by Reaction with
Ketenylidenetriphenylphosphorane
Educt
la
2a
3a
4a
5a
6a
Degree of
dideuteration [Oh] [a]
I5
95
I00
-
Icl
100
95
Degree of
silylation [Oh] [b]
I
By Hans Jurgen Bestmann,* Martin Schmidt, and
Rainer Schobert
15
30
55
21 [dl
70
53
3d
3d
I d
2h
Ih
3d
The readily accessible ketenylidenetriphenylphosphorane l " l reacts with Grignard reagents 2 to give addition
compounds of still unknown structure. Such adducts,
which are best formulated as in 3, are hydrolyzed by water
to acyl ylides 4. This reaction sequence thus enables a
chain-lengthening of 2 by two C atoms with concomitant
introduction of a carbonyl function and an ylide function
with C C coupling. Together with the secondary reactions
(carbonyl olefination and saponification) a possibility is
thus opened up for the acylation of Grignard compounds,
i.e. for the conversion of Grignard compounds into various
kinds of ketones."] Table 1 shows that this new methodology can be exploited for the synthesis of a wide spectrum
of ylides 4.13'
[a] ' H - N M R spectroscopically. [b] Determined on the isolated product. [c]
The proportion of 4d could not be determined because of signal overlapping.
[d) In competition with the second metalation, 4b rearranges to phenyllithium.
Only in the case of 5c was it possible to assign all the signals."'' The cause of the drastic line-broadening is, in our
opinion, the intermolecular cross-linking. Greater contributions to the widths at half height (W,,J by dynamic effects or by spin-spin coupling are unlikely. Thus, the W1,*
values"41 change neither with variation of temperature
(-50°C to +70°C) or concentration (0.4 to 2 . 2 M ) nor
with the use of the 6Li isotope. A deaggregation of the
cross-linked structures by addition of u p to ten molar
equivalents of various donors to solutions of 5c in T H F or
ether was not accomplished.[1515c can be stored for several
days at room temperature in solution without change.
1
Received: December 10, 1984:
revised: February 19, 1985 [Z 1106 IE]
German version: Angew. Chem. 97 (1985) 406
[ I ] L. I). McKeever, R. Waack, M. A. Doran, E. B. Baker, J . Am. Chem.
SUC.YO (1968) 3244: S. Bywater, P. Lachance, D. J. Worsfold, J . Phys.
Chem. 79 (1975) 2148: F. Wehrli, J . Magn. Reson. 30 (1978) 193.
[2] a ) G. Fraenkel, P. Pramanik, J . Chem. Soc. Chem. Cummun. 1983. 1527,
and references cited therein: b) D. Seebach, R. Hassig, J . Gabriel, H e l ~ ~ .
Chm. A m 66 (1983) 308, and references cited therein.
131 For the association behavior of organolithium compounds see, e.g.: T.
L. Brown. Pure Appl. Cliern. 23 (1970) 447; J . P. Oliver, Adu. Orgonumet.
Chem. I5 (1977) 235; J. L. Wardell in G. Wilkinson, F. G. A. Stone, E.
W. Abel: Cumprehensiue Organumetollic Chemisfry. Vul. I , Pergamon
Press, Oxford 1982, p. 43.
[4] 1,2-Dilithioethane is assumed as intermediate: V. Rautenstrauch, Angew.
Chem 87(1975) 254: Angew Chem. Int. Ed. Engl. 14 (1975) 259. It seems
to us that the synthesis of 1.2-dilithioethane from lithium and ethylene
(yield ?7-300/,) or from lithium and 1,2-dihdloethane (yield 6-9%) is
not confirmed: H. Kuus, Uch. Zap. Tarfu. Gus. Uniu. 193 (1966) 130
(Cheni. Abstr. 69 (1968) 67443q); Tartu Riikliku Ulik. Tuim. 219 (1968)
245 ((%em. Ahstr. 71 (1969) 49 155j).
[5] DANGER: Undissolved 4b has a tendency to decompose explosively!
[6] We ohtained no evidence of a diastereomeric mixture.
[7J R. P. Zerger, G. D. Stucky, J . Chem. SUC.Chem. Commun. 1973, 44.
[8J 3c ha5 already been detected: I. Murata, T. Nakazdwa, M. Kato, T. Tatsuoka, Y. Sugihara, Tetrahedron Lett. 1975. 1647.
[9J See, e.g.: J. W. Seetz, G. Schat, 0. S. Akkerman, F. Bickelhaupt, J . Am.
Chem. Suc. 104 (1982) 6848: P. von R. Schleyer, A. J. Kos, E. Kaufmann. ibid. I05 (1983) 7617.
[lo] H. Bogdanovic, B. Wermeckes, Angew. Chem. 93 (1981) 691: Angew.
Chem. lnt. Ed. Engl 20 (1981) 684.
[ I I ] According to Strerfwierer's "Ion-Triplet Model", directly adjacent dianionic charges are well stabilized by two monovalent cations: A. Streitwieser. Jr., Acc. Chem. Res. 17 (1984) 353.
(121 We found that deuterolysis does not always suffice for the quantitative
detection of bicyclobutane dianions. When Sa is treated with more than
two mole equivalents of nBuLi at - 30 "C in ether, according t o the 'HNMR spectrum, 5b is formed quantitatively with no 5c present. Nevertheless, after addition of this mixture to tenfold excess deuterium oxide, up to 60% 5d is obtained.
(131 Prepared with exactly (!) 2.0 mole equivalents of nBuLi.
(141 'H-NMR ([D,]THF; W,:>values ( & 15%) in Hz (in brackets); standard:
TMS int.): 6 ~ 0 . 5 (28:
9
2 H , 2-H, 5-H), 5.94 (22; 4 H , aromat. H): "CNMR iether/[D,]benzene): 6 (+ I ppm)=43 (130: C-2: C-5). 84 ( > 190:
C - I ; C-6). 116, 122 (30; aromat. C j ; 158 (50: C-3: C-4).
[ 151 Bis(dimethylaminojethane, [12]crown-4. hexamethylphosphoric acid
triamide (-6O"C), nBuLi/potassium tert-butoxide, and dimethoxyethane.
Anyen,. Chem lnt. Ed. Engl. 24 (19K5) N o . 5
6
il
Table 1. Yields and melting points of the acyl ylides 4 obtained by reaction
of 1 with 2 and subsequent hydrolysis.
Yield
R'
4
M.p. ["CJ
Yo1
C,H,
n-C,HP
CH(CH,)-(CH>)>-CH3
(CH,),rO-tetrdhydro- I-pyranyl
(CHz),-O-tetrahydro- 1-pyranyl
(CH2).- 1,3-dioxolan-2-yl
C(CH?j=CH*
CbH,
94
85
77
65
61
60
86
65
222 (221-222 [4])
oil
oil
oil
oil
oil
148
178 (178 151)
Compounds 4, which are usually recovered as oils and
can be readily purified by chromatography, show all the
typical, strongly shifted carbonyl bands for acyl ylides beTable 2. Yields and boiling points of the ketones 6 obtained by reaction of 4
with 5 . R ' , see Tdble 1.
6
R'
Yield
la4[a1
B.p. ["C/torr]
b
CH,
CsH,
C,H,
n-C,H,
n-C,H,.
(E)-CH=CH-(CHZ)z-CHI
54
52
42
38
36
48
68- 70/13 (65.5-66110
99- 101/0. I3
136- 140/0.01
122-126/0.05 [b]
69- 71/0.01
124-12610.3
c
d
e
g
h
[S])
[a] Referred t o 4 , not optimized. [b] Kugelrohr distillation, bath temperature.
[*I Prof. Dr. H. J. Restmann, DipLChem. M. Schmidt,
Dipl.-Chem. R. Schobert
Institut fur Organische Chemie der Universitat Erlangen-Nurnberg
Henkestr. 42, D-8520 Erlangen (FRG)
0 VCH Verlagsgesellschu/t mbH. 0-6940 Wrmheim, I985
0570-0833/85/0505-0405 $ 02.50/0
405
R. Luft, A n n . Chim. 4 (1959) 745.
M. Schwarz, R. W. Waters, Synthesis 1972. 567.
Review: H. I. Bestmann, 0. Vostrowsky, Chem. Phys. Lipids 24 (1979)
335.
M. Barbier, M. F. Hugel, Bull. SOC.Chim. Fr. 1961 I, 951.
For further syntheses cf. H. J. Bestmann, R. Kunstmann, H. Schulz, Juslux Liebigs Ann. Cheni. 699 (1966) 3 3 ; T. Fujisawa, T. Sato, T. Itoh,
Chem. Lett. 1982. 2 19.
tween 15 10 and 1530 c m - ' in their IR ~pectra.'~.''For further characterization, a Wittig reaction was carried out
with aldehydes 5 to give (E)-cr,P-unsaturated ketones 6.@'
Table 2 lists some examples."'
CH3-(C'Ii2),,,
1
H
HC I
(C H,),-OC O C €J3
c)
7d:
111 =
1 . n = 10;
7e:m
:
'3, n = 9
Reaction of compounds 6d and 6e with acetyl chloride
in glacial acetic acid['] furnished the corresponding acetates 7 in ca. 80% yield. They are carbonyl homologues of
lepidoptera pheromones,~'olwhich are of special interest
for structure-activity investigations (7d, 7e : b.p. (Kugelrohr) 105--108"C/0.01 torr and 120-123"C/O.Ol torr, respectively).
Hydrolysis[51of 4f afforded the acetal 8 (62% yield, b.p.
(Kugelrohr) 120- 123"C/ 13 torr), which after treatment
with acid to give the free 7-oxooctanal 9r''1was allowed to
react with the ylide 10. Subsequent saponification led to
formation of the queen substance 11 (57% yield based on
8, m.p. 52OC), which is thus relatively easily accessible.['*]
1) Ph3P=CfI-COOCH3
10
C)
It
* C H 3-C-( CH2)SHl
I
2) OHG
'COO€I
H'
11
Experimental
General procedure: 4 : A Grignard solution was prepared from magnesium
turnings (0.97 g, 40 mmol) and 40 mmol alkyl halide (preferably bromide) in
anhydrous tetrahydrofuran (THF) (final volume 150 mL). The boiling solution was treated dropwise over a period of 8-10 h with a solution of I
(9.06 g, 30 mmol) in T H F (150 mL) under N2; the final mixture was then
boiled under reflux for a further 2 h (in the case of 4g: reaction temperature
4 0 T , addition over a period of 4 h, then stirring for 2 h at 40"C).-After
cooling, the reaction mixture was poured into 60 m L of saturated ammonium
chloride solution, the aqueous phase separated off, and the solvent removed
from the organic phase. The residue was partitioned between 150 mL each of
dichloroniethane and water; the aqueous phase was extracted with dichloromethane, and the combined organic extracts were washed with a little water. After drying over magnesium sulfate, the solvent was removed by distillation and the residue was either recrystallized from ethyl acetate by addition
of ether or chromatographed on silica gel 60 [column height 20 cm, diameter
4 cm; hydrocarbon impurities were first eluted with hexane/ether (3 : I ) and
then 4 was eluted with ether/dichloromethane ( I : I)].
Received: December 14, 1984;
supplemented: January 25, 1985 [Z I 1 10 IEl
German version: Angew. Chem. 97 (19x5) 418
Synthesis and Structure of trunsIMCI(=C=CHR)(PiPr,),] (M= Rh, Ir): The First
Square-Planar Vinylidenemetal Complexes**
By Francisco Javier Garcia Alonso, Arthur Hohn,
Justin Wolf; Heiko Otto, and Helmut Werner*
Dedicated to Professor F. G . A . Stone on the occasion
of his 60th birthday
Vinylidenes :C=CRR', like carbenes :CRR' or other
highly reactive organic molecules, can be stabilized in the
coordination sphere of a transition metal. However, mononuclear square-planar vinylidenemetal complexes are, as
yet, unknown. Although it has been repeatedly postulated
that they are formed as intermediates in reactions of dX
compounds, e.g., of rhodium(]) with alkynes,"' their existence has not been proved.
Recently, we have shown that an equilibrium between
the alkyne complex la and the alkynyl(hydrid0) compound 2a exists in solution, and that on addition of pyridine this equilibrium is completely shifted to the right.["
Complex 3a, which gives 4a on reaction with NaC5H5 in
tetrahydrofuran (THF),"' is rather labile in solution and
reacts in benzene at room temperature by elimination of
pyridine to produce 5a. This compound is also obtained
almost quantitatively directly from l a , presumably via 2a
as
Similarly, the synthesis of 5b and 5 ~ ' ~ ' ~
has been achieved by the use of I b and lc as starting materials.'"]
Reaction of l b with pyridine gives the octahedral compound 3b, the properties of whichL5]closely correspond to
those of 3a. When R = H or Me, no five-coordinate intermediate of type 2 can be detected by NMR spectroscopy.
Ph
Ph
-
I
L
-Ill
I
H
406
0 VCH VerIagcgesell.~chafcmhH. D-6946 Weinheim.1985
-
Ph
PY
1Rh1,
K
/
@'
[Hhl-H
\
P 3'
[ Rh]=C =C,
Rh
\c
iPr,P'
[ I ] H. J. Bestmann, D. Sandmeier, Chem. Ber. 113 (1980) 274: Review: H. J.
Bestmann,Angew. Chem. 89 (1977) 361; Angew. Chem. Ini. Ed. Engl. 16
(1977) 349.
121 For further methods for the conversion of 2 into ketones cf. A. S.
Kende, D. Scholr, J. Schneider, Synfh. Commun. 8 (1978) 59: K. Utimoto, Y. Wakabayashi, Y. Shishiyama, M. Inoue, H. Nozaki, Tefrahedron
Letf. 22 (1981) 4279.
[3] For further methods for the synthesis of acyl ylides and their reactions
cf. H. I. Bestmann. Angew. Chem. 77 (1965) 651 ; AngeM?. Chem. I n f . Ed.
Engl. 4 (1965) 645; H. J. Bestmann, R. Zimmermann, Forfschr. Chem.
Forrch. 20 (1971) I .
(41 A. Fujiwara, H. Takahashi, M. Ohta, Bull. Chem. Soc. Jpn. 35 (1962)
2042.
[5j H. J. Bestmann, B. Arnason, Chem. Ber. 95 (1962) 1513.
[6j For the stereochemistry of the Wittig reaction cf. H. J. Bestmann, Pure
Appl. Chem. 52 (1980) 771.
(71 All the new compounds gave correct elemental analyses 'H-NMR, "PNMR, and mass spectra.
4'
/
H
5a
\C-Ph
I
4a
H
[lthl = RhC1(PiPr3)2
trans-[ RhCI( RC =C H)( PR;)J
-
trans-[RhCI(=C =C H R)(PR;),]
5a-12
la-c
a : R = P h ; b : R = M e ; c : R = H ; R'=iPr
[*] Prof. Dr. H. Werner. Dr. F. J. Garcia Alonso, Dipl.-Chem. A. Hohn,
[**I
Dipl.-Chem. J. Wolf, Dipl.-Chem. H. Otto
Institut fur Anorganische Chemie der Universitat
Am Hubland, D-8700 Wurzburg (FRG)
This work was supported by the Deutsche Forschungsgemeinschaft, the
Fonds der Chemischen Industrie, and Degussa AG.
OS7O-0833/SS/O505-0406 $ 02.80/0
Angew. Chem. Inf. Ed. Engl. 24 (1985) N o . 5
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