Reactions of allenyltri-n-butylstannane with halides of phosphorus, arsenic, antimony, germanium, tin, and boron. Preparation of propargylic and/or allenic derivatives

Article abstract of DOI:10.1021/om990543l

The reaction of allenyltri-n-butylstannane with a phosphorus or arsenic trihalide and with germanium tetrachloride gave the corresponding propargylic halophosphine, arsine, or germane. When they were heated, the propargylic products partially (P, Ge) or completely (As) rearranged into the corresponding allenyl derivatives, the thermodynamic products. The allenic or propargylic stannane reacted with stronger Lewis acidic halides such as a boron halide, antimony trichloride, or tin tetrachloride to give only the allenic product, even when the reaction was performed and analyzed at low temperature (-80°C). The propargylic intermediate was observed with the antimony and tin compounds when a substituted derivative (e. g. Vi₂SbCl, ViSnCl₃) was used. The reduction of the propargylic halide products prior to their isomerization gave the corresponding primary propargylic phosphine, arsine, germane, and stannane.

Full text of DOI:10.1021/om990543l

Organometallics 1999, 18, 5259-5263
5259
Rea ction s of Allen yltr i-n -bu tylsta n n a n e w ith Ha lid es of
P h osp h or u s, Ar sen ic, An tim on y, Ger m a n iu m , Tin , a n d
Bor on . P r ep a r a tion of P r op a r gylic a n d /or Allen ic
Der iva tives
J ean-Claude Guillemin* and Karine Malagu
Laboratoire de Synthe`ses et Activations de Biomole´cules, UPRES-A CNRS 6052, ENSCR,
Avenue du Ge´ne´ral Leclerc, 35700 Rennes, France
Received J uly 12, 1999
The reaction of allenyltri-n-butylstannane with a phosphorus or arsenic trihalide and with
germanium tetrachloride gave the corresponding propargylic halophosphine, arsine, or
germane. When they were heated, the propargylic products partially (P, Ge) or completely
(As) rearranged into the corresponding allenyl derivatives, the thermodynamic products.
The allenic or propargylic stannane reacted with stronger Lewis acidic halides such as a
boron halide, antimony trichloride, or tin tetrachloride to give only the allenic product, even
when the reaction was performed and analyzed at low temperature (-80 °C). The propargylic
intermediate was observed with the antimony and tin compounds when a substituted
derivative (e. g. Vi2SbCl, ViSnCl3) was used. The reduction of the propargylic halide products
prior to their isomerization gave the corresponding primary propargylic phosphine, arsine,
germane, and stannane.
In tr od u ction
gyldibromophosphine (2a ) in 73% yield.6 Small amounts
of allenyldibromophosphine (3a ; ∼10%) were observed
after the crude mixture was heated for 2 h at 120 °C.
The reaction of a mixture of arsenic trichloride and
stannane 1a at -20 °C gave propargyldichloroarsine
(2b) in 85% yield.7 The rearrangement in CDCl3 of
arsine 2b in the allenylarsine 3b occurred within a few
hours at room temperature in 95% yield.8 However, in
the reaction of SbCl3 with stannane 1a , propargyldi-
chlorostibine (2c) was not obtained, even when the
In the past two decades, numerous homopropargylic
alcohols and amines or their corresponding homoallenic
isomers have been prepared by reaction of allenic
stannanes with aldehydes or imines, respectively, in the
presence of various Lewis acids.1,2 Some mechanistic
studies have been carried out,3 but little has been done
to characterize the products formed by reaction of an
allenic stannane with a Lewis acidic element halide.
Here we report the preparation of several propargylic
compounds of phosphorus, arsenic, germanium, and tin
by reaction of the propadienyltri-n-butylstannane with
halides of these elements. The rearrangement of the
products to the corresponding allenyl derivatives was
studied. The reactivity of such compounds thus formed
with benzaldehyde as well as the reduction of the
propargylic element halides to the corresponding hy-
drides is also described.
1
reaction was carried out in CD2Cl2 and analyzed by H
NMR spectroscopy at -80 °C. Crude allenyldichlorostib-
ine (3c) was formed in 33% yield.8 A monochloro
derivative, divinylchlorostibine (4),8 reacted with stan-
nane 1a in CDCl3 to give divinyl-2-propargylstibine (2d )
in 87% yield. A distilled solution of 2d very slowly
rearranged at room temperature to give divinyl-
allenylstibine (3d ) in 90% yield (Scheme 1).9,10
(4) (a) Guillemin, J .-C.; Lassalle, L. Organometallics 1994, 13, 1525.
(b) Guillemin, J .-C.; Lassalle, L.; Dre´an, P.; Wlodarczak, G.; Demaison,
J . J . Am. Chem. Soc. 1994, 116, 8930. (c) Legoupy, S.; Lassalle, L.;
Guillemin, J .-C.; Me´tail, V.; Se´nio, A.; Pfister-Guillouzo, G. Inorg.
Chem. 1995, 35, 1466. (d) Lassalle, L.; Legoupy, S.; Guillemin, J .-C.
Organometallics 1996, 15, 3466. (e) J anati, T.; Guillemin, J .-C.;
Soufiaoui, M. J . Organomet. Chem. 1995, 486, 57. (f) Lassale, L.;
J anati, T.; Guillemin, J .-C. J . Chem. Soc. Chem. Commun. 1995, 699.
(5) (a) Le Serre, S.; Guillemin, J .-C. Organometallics 1997, 16, 5844.
(b) Le Serre, S.; Guillemin, J .-C.; Karpati, T.; Soos, L.; Nyula´szi, L.;
Veszpre´mi, T. J . Org. Chem. 1998, 63, 59.
(6) PBr3 gave better results and higher yields than PCl3. Several
allenylhalophosphines or propargylic monohalophosphines have been
prepared by other approaches. See for example: Simonnin, M.-P.;
Charrier, C. C. R. Acad. Sci. Paris, Ser. C 1968, 267, 550.
(7) The presence of small amounts (3%) of allenyldichloroarsine (3b)
in arsine 2b cannot be avoided.
Resu lts a n d Discu ssion
Allenic stannanes R3SnCHdCdCH2 could have had
a similar reactivity to that of R,â-unsaturated stannanes
(vinylic derivatives)4 or â,γ-unsaturated stannanes (al-
lylic derivatives).5 The answer was given by the reaction
of propadienyltri-n-butylstannane (1a ) with weak Lewis
acidic halides. At room temperature, the reaction of
stannane 1a with phosphorus tribromide gave propar-
(1) Pereyre, M.; Quintard, J .-P.; Rahm, A. Tin in Organic Synthesis;
Butterworth: London, 1987; pp 130-256.
(2) Marshall, J . A. Chem. Rev. 1996, 96, 31.
(3) (a) Marshall, J . A.; Perkins, J . J . Org. Chem. 1994, 59, 3509. (b)
Yamamoto, Y.; Shida, N. Adv. Detailed React. Mech. 1994, 3, 1. (c)
Marshall, J . A.; Perkins, J . F.; Wolf, M. A. J . Org. Chem. 1995, 60,
5556.
(8) The allenyldichloroarsine has been prepared previously by the
same approach, but without identification of the propargylarsine 2b
intermediate. Lassalle, L.; Legoupy, S.; Guillemin, J .-C. Inorg. Chem.
1995, 35, 5694.
10.1021/om990543l CCC: $18.00 © 1999 American Chemical Society
Publication on Web 11/10/1999

5260 Organometallics, Vol. 18, No. 25, 1999
Guillemin and Malagu
Sch em e 1
The reactivity of stannane 1a with group 14 element
halides increases from silicon to tin halides. No reaction
was observed between compound 1a and SiCl4 or SiBr4
even at 80 °C. Propargyltrichlorogermane (2e) was
prepared in 48% yield by reaction of GeCl4 with stan-
nane 1a at 40 °C. Heating of germane 2e at 120 °C for
some hours led only to very small amounts of allenyl-
trichlorogermane (3e).11 However, propargylgermane 2e
was obtained together with about 1% of germane 3e,
even starting from very pure stannane 1a . As the
temperature of the reaction is substantially lower than
the temperature of isomerization, we can conclude that
the formation of the propargylic compound occurs via
an allenyl-propargyl transposition with more than 99%
selectivity.
The reaction at -80 °C of SnCl4 with stannane 1a in
CD2Cl2 gave allenyltrichlorostannane (3f)4f in 86% yield,
as determined by low-temperature NMR spectroscopy.
Propargyltrichlorostannane was not detected. On the
other hand, vinyltrichlorostannane (5) reacted in CD2Cl2
with stannane 1a at a temperature lower than -80 °C
to give vinylpropargyldichlorostannane (2g) in 89%
yield. At -20 °C, the isomerization of 2g gave the
corresponding allenyl derivative 3g in 93% yield. Simi-
larly, at -80 °C, stannane 1a and tin tetrabromide in
CD2Cl2 reacted to give propargyltribromostannane (2h )
in 89% yield. It slowly rearranged around -20 °C to
allenyltribromostannane (3h ).
to effect clean exchange reactions. However, stannane
1a in CD2Cl2 reacted with BBr3 at a temperature lower
than -80 °C to give allenyldibromoborane (3i), which
was separated from n-Bu3SnBr by codistillation with the
solvent. Compound 3i has low stability at room tem-
perature, similar to allyldibromoborane,5a and is much
less stable than vinylic dibromoboranes.13 The addition
of dimethylbromoborane to an excess of stannane 1a
gave allenyldimethylborane (3j) in 84% yield. Even
when the reaction was performed at -80 °C in an NMR
tube, propargyldimethylborane (2j) was not observed.14
In the case of boron halides, we were not able to
demonstrate the formation of a propargylborane inter-
mediate.
Allenyl compounds 3a -j also were prepared by reac-
tion of the corresponding halide with propargyltriphe-
nylstannane (6).15 Yields ranged from 13 to 93% (Scheme
2). Partial rearrangement of propargylstannane 6 to the
corresponding allenyltriphenylstannane (1b) was ob-
served in the presence of weak Lewis acidic halides (PX3,
GeCl4), and thus, mixtures of allenyl- and propar-
gylphosphines or allenyl- and propargylgermanes, re-
spectively, in low yields, resulted in reactions with
stannanes 6 and 1b . However, the reaction of com-
pound 6 with stronger Lewis acidic halides (AsCl3,
H2CdCHSnCl3 5, SnX4, BCl3, ...) gave the allenic
products 3b,f-j exclusively in good yield. The propar-
gylic derivatives 2b,g,h , stable under the experimental
conditions, were not observed, thus proving that the
exchange reaction only occurs via a transposition reac-
tion.
Boron trihalides are strong Lewis acidic species, and
their addition to the carbon-carbon multiple bonds of
allenes or alkynes occurs easily12 and makes it difficult
(12) Vaultier, M.; Carboni, B. Boron. Comprehensive Organometallic
Chemistry II; Elsevier: Oxford, New York, Tokyo, 1995; Vol. 11,
Chapter 5, pp 191-276.
(9) The presence of small amounts (1-3%) of the propargylic isomer
are observed in almost all the allenyl compounds.
(10) The preparation of a few pentavalent propargylstibines has
been reported: Zhang, L.-J .; Mo, X.-S.; Huang, Y.-Z. J . Organomet.
Chem. 1994, 471, 77. To our knowledge, compound 2d is the first
trivalent propargylstibine described to date.
(11) The preparation of compounds 2e and 3e has been reported:
(a) Mironov, V. F.; Gar, T. K. Izv. Akad. Nauk. SSSR, Ser. Khim. 1965,
291. (b) Gar, T. K.; Nosova, V. M.; Kisin, A. V.; Mironov, V. F. Zh.
Obshch. Khim. 1978, 48, 838.
(13) Hall, L. W.; Odom, J . D.; Ellis, P. D. J . Am. Chem. Soc. 1975,
97, 4527.
(14) An equilibrium between nonisolated allenyl- and propargylbo-
rane has already been proposed, but the latter was considered to be
the thermodynamic product: (a) Zweifel, G.; Backlund, S. J .; Leung,
T. J . Am. Chem. Soc. 1978, 100, 5561. (b) Zweifel, G.; Pearson, N. R.
J . Org. Chem. 1981, 46, 829.
(15) Le Quan, M.; Cadiot, P. Bull. Soc. Chim. Fr. 1965, 45.

Reactions of Allenyltri-n-butylstannane
Organometallics, Vol. 18, No. 25, 1999 5261
Sch em e 2
F igu r e 1.
to the presence of substituents inhibits the isomeriza-
tion of the primary product.
The strong correlation between the temperature of
reaction of Lewis acidic halides with stannanes 1a and
6, the temperature of rearrangement of the propargylic
product in the allenyl derivative, and the chemical
reactivity with electrophiles gives a new scale for the
strength of Lewis acids (Figure 1). The major difference
between this scale and the ones reported in the litera-
ture20 is the particular role played by the Lewis acidic
halides of group 15. In our approach, PCl3 is more acidic
than SiCl4 or SiBr4, AsCl3 more so than GeCl4, and
SbCl3 more so than any tin halide.21 This scale is also
consistent with reactions involving Lewis acidic halides
and allylic stannanes5 and corroborates postulated
mechanisms reported elsewhere.22
The selective preparation of propargyl halo com-
pounds (2a ,b,e,h ) in reactions of weak Lewis acidic
halides provides a short route to the corresponding
primary propargyl derivatives. Using Bu3SnH in the
presence of small amounts of duroquinone (a radical
inhibitor),23 we prepared the primary propargylphos-
phine 9a ,24 arsine 9b, germane 9e, and stannane 9h
(eq 3). The latter was only obtained from a reaction with
The reactivity of propargylic and allenic compounds
2 and 3 with electrophiles is dependent on the hetero-
atom and the other substituents. As an example, reac-
tions of boranes 3i,j with acetone gave, after hydrolysis
of the reaction mixture, 4-methyl-1-pentyn-4-ol (7)16,17
(eq 1). At -78 °C, reactions of benzaldehyde with
tribromostannane 2h and the presence of the isomeric
allenylstannane (∼30%) cannot be avoided. Compound
2h can thus be considered as the strongest Lewis acidic
halide that can be reduced using this approach before
its isomerization. The yields of 9a ,b,e,h ranged from 22
to 78%. Arsine 9b, in CDCl3 solution, exhibited low
stability at room temperature (τ1/2 ≈ 3 h), while solu-
tions of compounds 9a ,e,h are stable under similar
conditions. Only yellow-brown decomposition products
were observed when 9b was warmed to room temper-
ature.
stannane 1a and compounds 3c,f18 gave the homopro-
pargylic alcohol 816 (eq 2). Under similar conditions, but
using SnBr4 or vinyltrichlorostannane 5 as the halide,
the reaction occurred only at a temperature higher than
-40 °C. At room temperature and after several hours
of stirring, no product was observed in attempted
reactions of benzaldehyde with compounds 2a ,b,e,
3a ,b,e, and stannane 1a .
The formation of homoallenyl alcohols occurs when
moderately strong Lewis acidic halides (5, SnBr4,
BuSnCl319) are used. With these Lewis acidic halides,
the propargylic tin halide product, easily observed at
low temperature, reacts with the electrophile at a
temperature lower than that of isomerization. However,
such trapping reactions have been performed using a
stronger Lewis acidic halide such as SnCl4 but at a lower
temperature (-78 °C) and using allenylstannanes sub-
stituted on the CdC bonds;19 the steric hindrance due
Con clu sion
We have shown that the reaction of weak to moder-
ately strong Lewis acidic halides with the allenyltri-n-
butylstannane leads only to the corresponding propar-
gylic derivative, the kinetic product via a transposition
(20) Childs, R. F.; Mulholland, D. L.; Nixon, A. Can. J . Chem. 1982,
60, 801.
(16) Compounds 7 and 8 have been identified by comparison with
authentic samples. 7: Gerard, F.; Miginiac, P. J . Organomet. Chem.
1976, 111, 17. 8: Mondon, A. J ustus Liebigs Ann. Chem. 1952, 577,
181.
(17) For the reaction of 9-allenyl-9-BBN with ketones see: Brown,
H. C.; Khire, U. R.; Racheria, U. S. Tetrahedron Lett. 1993, 34, 15.
(18) The use of SnCl4 in such reactions has been reported previously.
See for example refs 1-3.
(19) n-BuSnCl3 has been used as a Lewis acid to selectively prepare
homoallenic alcohols: (a) Marshall, J . A.; Yu, R. H.; Perkins, J . F. J .
Org. Chem. 1995, 60, 5550. (b) Marshall, J . A.; Palovich, M. R. J . Org.
Chem. 1997, 62, 6001.
(21) The effectiveness of antimony or bismuth halides as Lewis acids
has already been reported previously; see for example: (a) Komatsu,
N.; Uda, M.; Suzuki, H.; Takahashi, T.; Domae, T.; Wada, M.
Tetrahedron Lett. 1997, 38, 7215. (b) Le Roux, C.; Mandrou, S.; Dubac,
J . J . Org. Chem. 1996, 61, 3885.
(22) See for example: Masuyama, Y.; Ito, A.; Terada, K.; Kurusu,
Y. Chem. Commun. 1998, 2025.
(23) Numerous primary R,â-unsaturated compounds have been
prepared using this reagent. See ref 4.
(24) Propargylphosphine 9a can be synthesized by the reaction of
LiAl(PH2)4 with propargyl bromide: Shay, R. H.; Diel, B. N.; Schubert,
D. M.; Norman, A. D. Inorg. Chem. 1988, 27, 2378.

5262 Organometallics, Vol. 18, No. 25, 1999
Guillemin and Malagu
(45.1) [PBr2]+, 191 (97.7) [PBr2]+, 189 (46.0) [PBr2]+, 151 (77.1)
[C3H3PBr]+, 149 (79.0) [C3H3PBr]+, 69 (100) [C3H2P]+.
P r op a r gyld ich lor oa r sin e (2b). Yield: 85%. At room
temperature, compound 2b slowly isomerized in 3b. τ1/2 (5%
in CDCl3, room temperature): 3 h. Bp: 30 °C (0.1 mmHg). 1H
NMR (CDCl3, -30 °C): δ 2.41 (t, 1H, 4J HH ) 2.8 Hz, CH); 3.31
(d, 2H, 4J HH ) 2.8 Hz, CH2). 13C NMR (CDCl3, -30 °C): δ 32.6
(t, J CH ) 144.7 Hz, CH2); 74.4 (d, J CH ) 253.2 Hz, CH); 75.8
(d, 2J CH ) 51.1 Hz, HCtC). HRMS: m/z calcd for C3H3As35Cl2,
183.8828; found, 183.883. MS: m/z (%) 186 (11.2), 184 (16.9),
149 (31.2) [C3H3AsCl]+, 148 (27.3) [C3H2AsCl]+, 147 (26.5)
[AsCl2]+, 145 (46.6) [AsCl2]+, 113 (28.4) [C3H2As]+, 39 (100)
[C3H3]+.
reaction. This latter species rearranges to the allenic
isomer (the thermodynamic product) at a temperature
dependent on this Lewis acid. This approach allows the
synthesis of numerous propargylic derivatives. The
reactivity and stability of propargylic or allenic hetero-
compounds can be attributed to a large interaction
between the CγCâ multiple bond and carbon-hetero-
atom bonds. Consequently, the allenic derivatives ex-
hibit properties similar to those of allylic derivatives and
not at all like those of R,â-unsaturated compounds.
The chemoselective reduction of these propargylic
derivatives, before their isomerization, opens a general
route to the synthesis of low-boiling primary propargylic
arsines, germanes, and stannanes.
1
1
P r op a r gyld ivin ylstibin e (2d ). Yield: 87%. Purity: >90%,
contained 5-10% of stibine 3d . At room temperature, com-
pound 2d slowly isomerized to 3d . τ1/2 (5% in CDCl3, room
temperature): 12 h. Bp: ∼-50 °C (0.1 mmHg). 1H NMR
(CD2Cl2, -30 °C): δ 2.05 (t, 1H, 4J HH ) 2.9 Hz, HCt); 2.19 (d,
Exp er im en ta l Section
4
3
2H, J HH ) 2.9 Hz, CH2Sb); 5.87 (d, 1H, J HHtrans ) 19.6 Hz,
1
Gen er a l Con sid er a tion s. H (400 MHz), 31P (125 MHz),
3
HCHd); 6.27 (d, 1H, J HHcis ) 12.3 Hz, HCHd); 6.94 (dd, 1H,
and 13C NMR (100 MHz) spectra were recorded on a Bruker
ARX400 spectrometer and 11B NMR (96.3 MHz) or 119Sn NMR
(112 MHz) on a Bruker AC 300C spectrometer. Chemical shifts
are given in ppm (δ) relative to tetramethylsilane (1H) or to
solvent (13C, CDCl3, δ 77.0 ppm), external Me4Sn for 119Sn
NMR spectra, external H3PO4 for 31P NMR spectra, and
external BF3‚Et2O for 11B NMR spectra. The NMR spectra
were recorded using CDCl3 or CD2Cl2 as solvent. High-
resolution mass spectra (HRMS) were obtained on a Varian
MAT 311 instrument. To record the mass spectra, the pro-
pargylarsine 9b, germane 9e, and stannane 9h were directly
introduced from a cooled cell into the ionization chamber of
the spectrometer. The yields and half-lives (τ1/2) of the unsta-
bilized derivatives were determined by 1H NMR with an
internal reference. The spectroscopic characterization of com-
pounds 3b,8 3c,8 3f,4f 4,8 and 54e has been reported previously.
Gen er a l P r oced u r e for th e Rea ction of Sta n n a n e 1a
w ith Lew is Acid ic Ha lid es. Into a two-necked flask equipped
with a nitrogen inlet and a magnetic stirring bar, the Lewis
acid (1 mmol) and 5 mL of CH2Cl2 were introduced. The flask
was immersed in a cold bath (PBr3, AsCl3, and GeCl4 at -20
°C; 4, 5, SnCl4, Me2BBr, and BCl3 at -80 °C) and propadi-
enyltri-n-butylstannane (1a ; 1 equiv) in CH2Cl2 (2 mL) was
slowly added. The mixture was stirred for 10 min (mixtures
containing PBr3 or GeCl4 were stirred for 20 min at 40 °C).
The flask was then fitted on a vacuum line and the product
purified by trap-to-trap distillation at 0.1 mbar into a receiver
at -30 °C.
3J HHtrans ) 19.6 Hz, 3J HHcis ) 12.3 Hz, CHd). 13C NMR (CD2Cl2,
1
-30 °C): δ 2.80 (t, CH2); 68.9 (d, J CH ) 248.7 Hz, HCtC);
2
1
82.9 (d, J CH ) 50.0 Hz, HCtC); 133.6 (t, J CH ) 157.5 Hz,
1
HCdCH2); 136.4 (d, J CH ) 157.0 Hz, HCdCH2).
P r op a r gyltr ich lor oger m a n e (2e).11a Yield: 105 mg (48%).
1H NMR (CDCl3): δ 2.33 (t, 1H, J HH ) 2.9 Hz, CH); 2.93 (d,
4
4
1
2H, J HH ) 2.9 Hz, CH2). 13C NMR (CDCl3): δ 20.9 (t, J CH
)
2
1
141.0 Hz, CH2), 73.0 (d, J CH ) 51.1 Hz, HCtC); 73.7 (d, J CH
) 254.0 Hz, CH).
Vin ylp r op a r gyld ich lor ost a n n a n e (2g). Yield: 89%
(crude). Around -20 °C, compound 2g slowly isomerized to
3g. τ1/2 (5% in CD2Cl2, -15 °C): 15 min. 1H NMR (CD2Cl2, -60
4
4
°C): δ 2.26 (t, 1H, J HH ) 2.9 Hz, J SnH ) 50.8 Hz (d), CH);
4
2
2.70 (d, 2H, J HH ) 2.9 Hz, J SnH ) 88.8 Hz (d), CH2); 6.20 (d,
3
3
1H, J HHtrans ) 19.2 Hz, HCHd); 6.48 (d, 1H, J HHcis ) 12.0
3
3
Hz, HCHd); 6.59 (dd, 1H, J HHtrans ) 19.2 Hz, J HHcis ) 12.0
Hz, HCd). 13C NMR (CD2Cl2, -60 °C): δ 14.5 (t, 1J CH ) 141.9
1
1
2
Hz, J SnC ) 518.6 Hz (d), CH2); 75.4 (d, J CH ) 252.3 Hz, J SnC
1
3
) 108.6 Hz (d), CH); 76.3 (d, J CH ) 51.2 Hz, J SnC ) 86.2 Hz
1
1
(d), CtC); 134.2 (d, J CH ) 170.3 Hz, J SnC ) 733.1 Hz (d),
dCH); 140.2 (t, J CH ) 161.3 Hz, dCH2). 119Sn NMR (CDCl3,
1
-50 °C): -13.2.
P r op a r gyltr ibr om osta n n a n e (2h ). Yield: 91% (crude).
Around -20 °C, compound 2h slowly isomerized into 3h . τ1/2
1
(5% in CD2Cl2, -15 °C): 15 min. H NMR (CD2Cl2, -60 °C):
4
δ 2.59 (t, 1H, 4J HH ) 2.9 Hz, J SnH ) 85.5 Hz (d), CH); 3.24 (d,
2H, 4J HH ) 2.9 Hz, 2J SnH ) 95.9 Hz (d), CH2). 13C NMR (CD2Cl2,
-60 °C): δ 20.9 (t, 1J CH ) 148.6 Hz, 1J SnC ) 597.2 Hz (d), CH2);
1
3
With high-boiling Lewis acidic halides (antimony halides)
or when the propargylic isomer was not observed after distil-
lation (stannanes, boranes), the reaction was performed at -90
°C in an NMR tube using CD2Cl2 as solvent. The sample was
analyzed by low-temperature (-90 °C) NMR spectroscopy.
Thus, compounds 2g,h were observed.
The allenyl derivatives 3d ,g-j were prepared by a similar
procedure. The corresponding Lewis acidic halide was reacted
with stannane 1a or 6. Phosphine 3a and germane 3e were
prepared by reacting PBr3 and GeCl4, respectively, with
stannane 6 at room temperature, followed by 2 h of stirring
at 120 °C. Purification of 3a ,d ,e,f-j was performed by distil-
lation.
75.4 (d, J CH ) 254.4 Hz, J SnC ) 73.4 Hz (d), CH); 76.6 (s,
2J SnC ) 100.0 Hz (d), CtC). 119Sn NMR (CDCl3, -50 °C): δ
-202.7.
Allen ic Com p ou n d s 3a ,d ,e,g-j. Allen yld ibr om op h os-
1
p h in e (3a ). Yield: 53 mg (23%). Bp: 30 °C (0.1 mmHg). H
4
NMR (CDCl3, room temperature): δ 5.30 (dd, 2H, J PH ) 6.6
4
2
4
Hz, J HH ) 3.3 Hz, CH2); 6.45 (dt, 1H, J PH ) 10.6 Hz, J HH
)
3.3 Hz, CH). 13C NMR (CDCl3, room temperature): δ 78.1 (td,
1J CH ) 171.0 Hz, J CP ) 9.7 Hz, CH2); 92.3 (dd, J CH ) 181.6
3
1
1
2
Hz, J CP ) 59.3 Hz, HC); 209.9 (d, J CP ) 11.2 Hz, CdCdC).
31P NMR (CDCl3): δ 148.0 (d, J PH ) 10.6 Hz). HRMS: m/z
2
calcd for C3H3PBr2, 227.8339; found, 227.834.
Allen yld ivin ylstibin e (3d ). Yield: 92% (starting from 2d ).
1
Bp: ∼-50 °C (0.1 mmHg). H NMR (CD2Cl2, room tempera-
P r op a r gylic Com p ou n d s 2a ,b,d ,e,g,h . P r op a r gyld ibr o-
m op h osp h in e (2a ). Yield: 168 mg (73%). Bp: 32 °C (0.1
4
ture): δ 4.40 (d, 2H, J HH ) 6.8 Hz, H2CdCdC); 5.40 (d, 1H,
3
4J HH ) 6.8 Hz, CdCdCH); 5.82 (d, 1H, J HHtrans ) 19.5 Hz,
1
mmHg). H NMR (CDCl3, room temperature): δ 2.39 (dt, 1H,
3
4
2
4J PH ) 5.2 Hz, J HH ) 2.8 Hz, CH2); 3.59 (dd, 2H, J PH ) 16.1
HCHd); 6.21 (d, 1H, J HHcis ) 12.2 Hz, HCHd); 6.82 (dd, 1H,
3
3J HHtrans ) 19.5 Hz, J HHcis ) 12.2 Hz, dCH). 13C NMR
Hz, 4J HH ) 2.8 Hz, CH). 13C NMR (CDCl3, room temperature):
1
1
1
2
(CDCl3): δ 67.8 (t, J CH ) 168.1 Hz, CH2dCdC); 74.4 (d, J CH
δ 30.6 (dt, J CH ) 147.9 Hz, J CP ) 48.0 Hz, CH2); 73.8 (dd,
) 173.1 Hz, CH2dCdCH); 132.9 (t, 1J CH ) 156.8 Hz, CHdCH2);
1J CH ) 252.9 Hz, 3J CP ) 7.8 Hz, CH); 76.8 (dd, 2J CP ) 11.5 Hz,
1
2J CH ) 49.9 Hz, HCtC). 31P NMR (CDCl3): δ 164.1 (t, J PH
)
2
133.5 (d, J CH ) 158.1 Hz, HCdCH2); 209.2 (s, CdCdC).
16.1 Hz). HRMS: m/z calcd for C3H3P79Br2: 227.8339, found:
227.835. MS: m/z (%) 232 (11.5), 230 (23.1), 228 (11.9), 193
Allen yltr ich lor oger m a n e (3e).11b Yield: 13% (contained
germane 2e). 1H NMR (CDCl3): 5.15 (t, 1H, J HH ) 6.9 Hz,
4

Reactions of Allenyltri-n-butylstannane
Organometallics, Vol. 18, No. 25, 1999 5263
4
CH); 5.63 (t, 2H, J HH ) 6.9 Hz, CH2). 13C NMR (CDCl3): δ
Caution! Primary propargylic phosphine, arsine, germane,
and stannane are pyrophoric and potentially highly toxic. All
reactions and handling should be carried out in a well-
ventilated hood.
1
1
76.9 (t, J CH ) 171.0 Hz, CH2); 84.3 (d, J CH ) 183.1 Hz, CH);
212.9 (s, CdCdC).
Allen ylvin yld ich lor osta n n a n e (3g). Yield: 228 mg (93%)
(starting from 2g). Bp: 44 °C (0.1 mmHg). H NMR (CDCl3):
δ 4.85 (d, 2H, J HH ) 6.6 Hz, CdCdCH2); 5.50 (t, 1H, J HH
6.6 Hz, HCdCdC); 6.18 (d, 1H, J HHtrans
1
The apparatus already described for the reduction of alkyn-
yl- and allenylarsines was used.4,5b The flask containing the
reducing mixture (20 mmol of Bu3SnH containing about 5 mg
of duroquinone (2a ,b,h ) or LiAlH4 (20 mmol) in tetraglyme
(10 mL) (2e)) was cooled to -30 °C, fitted on a vacuum line,
and degassed. The pure (2a ,e) or crude and cooled (2b,h )
precursor (1 mmol) in decahydronaphthalene (5 mL) was then
added with a short flex needle through the septum. During
and after the addition, the product was distilled off in vacuo
from the reaction mixture. A cold trap (-70 °C) selectively
removed the less volatile products, and compounds 9a ,b,e,h
were condensed in a second cold trap (-110 °C) to remove the
most volatile products. After revaporization, the pure product
was condensed on a cold finger (-196 °C) which was connected
at the bottom to a flask or an NMR tube. A cosolvent was
added at this step. After it was disconnected from the vacuum
line by stopcocks, the apparatus was filled with dry nitrogen;
liquid nitrogen was subsequently removed. The product was
collected and kept at low temperature (<-40 °C) before
analysis. The boiling points of products 9b,e,h have been
approximately determined ((5 °C) from their temperature of
condensation and revaporization in vacuo (0.1 mbar).
4
4
)
3
) 19.3 Hz,
3
HCHdC-Sn); 6.47 (d, 1H, J HHcis ) 11.2 Hz, HCHdCH-Sn);
3
3
6.53 (dd, 1H, J HHtrans
)
19.3 Hz, J HHcis
)
11.2 Hz,
H2CdCH-Sn). 13C NMR (CDCl3): δ 71.7 (t, J CSn ) 101 Hz,
3
1
CdCdCH2); 79.9 (d, J CSn ) 753 Hz, CdCdCH2); 133.3 (d,
2
H2CdCH-Sn); 140.0 (t, J CSn ) 69.4 Hz, H2CdC-Sn); 212.9
(s, CdCdC). 119Sn NMR (CDCl3): δ -35.7. HRMS: m/z calcd
for C5H535Cl2120Sn ([M - H]+), 254.8790; found, 254.879.
Allen yltr ibr om osta n n a n e (3h ). Yield: 329 mg (93%)
1
(starting from 2h ). Bp: 48 °C (0.1 mmHg). H NMR (CDCl3):
4
4
δ 5.16 (d, 2H, J HH ) 6.7 Hz, J SnH ) 120.1 Hz (d), CH2); 5.82
(t, 1H, J HH ) 6.7 Hz, J SnH ) 151.4 Hz (d), CH). 13C NMR
4
2
(CDCl3): δ 75.6 (t, 1J CH ) 171.2 Hz, 3J SnC ) 151.6 Hz (d), CH2);
1
1
83.7 (d, J CH ) 190.5 Hz, J SnC ) 937.2 Hz (d), CH); 209.1 (s,
2J SnC ) 57.5 Hz (d), CdCdC). 119Sn NMR (CDCl3): δ -251.
HRMS: m/z calcd for C3H379Br3120Sn, 395.6808; found, 395.677.
Allen yld ibr om obor a n e (3i). Yield: 42%. Compound 3i
decomposes at room temperature into insoluble brown prod-
ucts. τ1/2 (5% in CD2Cl2, room temperature): 20 min. 1H NMR
4
(CD2Cl2, -30 °C): δ 4.90 (d, 2H, J HH ) 6.4 Hz, CH2); 5.96 (t,
1H, 4J HH ) 6.4 Hz, CH). 13C NMR (CD2Cl2, -30 °C): δ 73.1 (t,
1J CH ) 170.5 Hz, CH2); 94-96 (brd, CH); 224.1 (CdCdC). 11B
NMR (CD2Cl2): δ 57.5.
P r op a r gyla r sin e (9b). Yield: 42%. Bp: ∼-85 °C (0.1
1
mmHg). τ1/2 (5% in CDCl3, room temperature): 3 h. H NMR
Allen yld im eth ylbor a n e (3j). Yield: 67 mg (84%). Bp:
4
(CDCl3, -30 °C): δ 2.17 (t, 1H, J HH ) 2.8 Hz, CH); 2.38 (td,
1
∼-65 °C (0.1 mmHg). H NMR (CDCl3): δ 0.82 (s, 6H, CH3);
3
4
3
2H, J HH ) 6.2 Hz, J HH ) 2.8 Hz, CH2); 2.87 (t, 2H, J HH
)
)
)
4
4
4.61 (d, 2H, J HH ) 6.4 Hz, CH2); 5.58 (t, 1H, J HH ) 6.4 Hz,
1
6.2 Hz, AsH2). 13C NMR (CDCl3, -30 °C): δ -0.9 (t, J CH
140.4 Hz, CH2); 69.0 (d, J CH ) 249.5 Hz, CH); 84.9 (d, J CH
1
CH). 13C NMR (CDCl3): δ 8.4 (q brd, J CH ≈ 127 Hz, CH3);
1
2
68.1 (t, 1J CH ) 167.9 Hz); 89-92 (brd, CH); 219.1 (s, CdCdC).
11B NMR (CDCl3): δ 76.5. HRMS: m/z calcd for C5H911B,
80.0797; found, 80.0795.
46.4 Hz, HCtC). HRMS: m/z calcd for C3H5As, 115.9607;
found, 115.961. MS: m/z (%) 116 (32.6), 115 (18.7) [M - H]+,
114 (11.1) [M - 2H]+, 76 (88.2) [AsH]+, 39 (100) [C3H3]+.
Rea ction of a n Allen ylbor a n e w ith Aceton e. Solutions
of compounds 3i,j (1 mmol) in CH2Cl2 (10 mL) were cooled to
-78 °C, and solutions of acetone (1 mmol) in CH2Cl2 (5 mL)
were slowly added. The mixtures were stirred for 10 min at
this temperature and then hydrolyzed with saturated aqueous
NaHCO3. The 4-methyl-1-pentyn-4-ol (7) produced was puri-
fied by column chromatography (hexane/ether) and character-
ized by comparison with an authentic sample.16 Yields: 45 (3i)
and 95% (3j).
P r op a r gylger m a n e (9e). Yield: 78%. Bp: ∼-90 °C (0.1
1
4
mmHg). H NMR (CDCl3): δ 1.95 (t, 1H, J HH ) 2.9 Hz, CH);
4
3
1.87 (dq, 2H, J HH ) 2.9 Hz, J HH ) 3.2 Hz, CH2); 3.87 (t, 3H,
3J HH ) 3.2 Hz, GeH3). 13C NMR (CDCl3): δ -3.7 (t, J CH
)
)
1
1
2
135.3 Hz, CH2); 67.4 (d, J CH ) 248.7 Hz, CH); 82.8 (s, J CH
48.6 Hz, HCtC). HRMS: m/z calcd for C3H5Ge [M - H]+,
114.9603; found, 114.959. MS: m/z (%) 116 (11.8), 115 (36.0)
[M - H]+, 74 (71.4) [Ge]+, 72 (55.4) [Ge]+, 39 (100) [C3H3]+.
Rea ction of Allen ylstibin e 3c or -sta n n a n e 3f w ith
Ben za ld eh yd e. Solutions of compounds 3c,f (1 mmol) in
CH2Cl2 (10 mL) were cooled to -78 °C, and solutions of
benzaldehyde (1 mmol) in CH2Cl2 (5 mL) were slowly added.
The mixtures were stirred for 2 h at this temperature and then
hydrolyzed with saturated aqueous NaHCO3. The 1-phenyl-
3-butyn-1-ol (8) produced was purified by column chromatog-
raphy (hexane/ether) and characterized by comparison with
an authentic sample.16 Yields: 53% (3c), 78% (3f).
Ad d ition of Ben za ld eh yd e to P r op a r gylic Com p ou n d s
2a ,b ,e or Allen ic Com p ou n d s 3a ,b ,e. Compounds 2a ,b ,e
and 3a ,b,e (1 mmol) were prepared as reported above and
diluted with CH2Cl2 (10 mL). A solution of benzaldehyde (1
mmol) diluted with CH2Cl2 (5 mL) was slowly added at 0 °C.
The mixture was stirred for 2 h at room temperature and then
hydrolyzed with saturated aqueous NaHCO3. No product was
detected.
P r op a r gylst a n n a n e (9h ). Yield: 22% (crude, contained
allenylstannane). Bp: -80 °C (0.1 mmHg). 1H NMR (CD2-
4
3
2
Cl2): 1.87 (qd, 2H, J HH ) 2.9 Hz, J HH ) 1.9 Hz, J SnH ) 70.0
Hz, H2C); 1.94 (t, 1H, 4J HH ) 2.9 Hz, HCtC); 4.90 (t, 3H, 3J HH
) 1.9 Hz, SnH3). 13C NMR (CD2Cl2): δ -8.5 (q, CH3); 67.0 (d,
CH); 80.0 (s, CtCH). 119Sn NMR (CD2Cl2): δ -313 (1J SnH
)
1972 Hz). HRMS: m/z calcd for [M - H]+ (C3H5120Sn)+,
160.9413; found, 160.941.
Ack n ow led gm en t . We thank the PNP (INSU-
CNRS) for financial support.
Su p p or tin g In for m a tion Ava ila ble: 1H and 13C NMR
spectra of compounds 2a ,b,d ,e,g,h , 3a ,d ,g-j, and 9b,e,h . This
material is available free of charge via the Internet at
http://pubs.acs.org.
Gen er a l P r oced u r e for t h e P r ep a r a t ion of t h e P r o-
p a r gylic P h osp h in e 9a , Ar sin e 9b, Ger m a n e 9e, or Sta n -
n a n e 9h .
OM990543L