Synthesis of extended polyphosphacumulenes

Article abstract of DOI:10.1002/chem.200600829

Addition of two equivalents of (Me₃Si)₂CLiCl to the C-[(diphenyl) (diisopropylamino)phosphonio]-P-(diisopropylamino)phosphaalkene 2 affords the 1σ⁴,3σ³-diphosphabuta-1,2,3-triene E1 in 55% yield. Derivative E1 w

Full text of DOI:10.1002/chem.200600829

FULL PAPER
DOI: 10.1002/chem.200600829
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Chem. Eur. J. 2006, 12, 8444 – 8450

FULL PAPER
Synthesis of Extended Polyphosphacumulenes
N
David Martin,[a, b] Fook S. Tham,[a] Antoine Baceiredo,*[b] and Guy Bertrand*[a]
Abstract: Addition of two equivalents
of (Me3Si)2CLiCl to the C-[(diphenyl)
(diisopropylamino)phosphonio]-P-(di-
phorane 5, which was isolated in 84%
yield. Because the second carbon
center is also nucleophilic, cumulene
E1 reacts as a “pincer” with BF3·OEt2,
leading to the formation of a novel
four-membered PCBC heterocycle 6
with a betaine-like structure. Addition
of three equivalents of P-[diphenyl(di-
A
isopropylamino)phosphaalkene
2
af-
ane to (diisopropylamino)dichloro-
phosphane, followed by addition of one
fords the 1s4,3s3-diphosphabuta-1,2,3-
triene E1 in 55% yield. Derivative E1
equivalentof CCl , and subsequentde-
4
was fully characterized, including
a
protonation with lithium hexamethyldi-
silazide gave rise to 1s4,3s3,5s4-triphos-
phapenta-1,2,3,4-tetraene F1, which
was isolated in 62% yield.
single-crystal X-ray diffraction study.
Alkylation of E1 with methyl trifluoro-
methanesulfonate gives rise to the first
C-phosphonio-bis(methylene)phos-
Keywords: bis(methylene)phos-
phoranes · cumulenes · phospha-
cumulenes · phosphorus · ylides
Although all-carbon cumulenes [R2C=(C=)nCR2] have
been extensively studied,[1] the construction of stable phos-
phorus-containing cumulenes remains very challenging. This
is partly due to the weakness of phosphorus–carbon multiple
bonds,[2] but also to the lack of synthetic methodologies. So
far, cumulenes exclusively based on phosphorus–carbon
double bonds[3] are limited to 1s4,3s4-diphosphaallenes (car-
bodiphosphoranes) A,[4] 1s2,3s2-diphosphaallenes B,[3c,5] bis-
Scheme 1. Schematic representations of the known P,C-containing cumu-
lenes A–D, and of those reported herein E and F.
A
1s4,3s2-diphosphaallenes D[7,8] (Scheme 1). Here, we report
the synthesis of the first representatives of phosphorus/
carbon cumulenes featuring three[9] (E) and even four phos-
phorus–carbon “double bonds” (F) (Scheme 1).
Bis(methylene)phosphoranes C are classically prepared
by addition of a carbenoid to a phosphaalkene.[6,10] Howev-
er, according to 31P NMR spectroscopy, addition of 1s4,3s2-
diphosphaallene 1 to lithium bis(trimethylsilyl)chlorometha-
nide (3)[11] led to a complex mixture of products, with no sig-
nals corresponding to the desired cumulene E1. To enhance
the electrophilicity of the phosphorus center, we turned our
attention to the protonated form 2[7,12] of the diphosphaal-
lene 1 (Scheme 2). When one equivalentof carbenoid 3 was
used, the desired nucleophilic addition to the phosphorus
center, as well as the subsequent 1,2-Cl shift[13] occurred, but
instead of obtaining the P-chloro compound 4, we observed
the quantitative formation of the fluoro derivative 4’. All at-
tempts to eliminate HF from 4’ failed. To preventht e halo-
gen exchange, phosphonio phosphaalkene 2 was added to
two equivalents of 3 (one for the addition reaction and one
as a base to eliminate HCl from 4) at À1008C, and 1s4,3s3-
diphosphabuta-1,2,3-triene E1 was isolated as yellow crystals
in 55% yield.
[a] Dr. D. Martin, F. S. Tham, Prof. G. Bertrand
UCR-CNRS Joint Research Chemistry Laboratory (UMI 2957)
Department of Chemistry, University of California, Riverside
CA 92521–0403 (USA)
Fax : (+1)951-827-2725
E-mail: gbertran@mail.ucr.edu
[b] Dr. D. Martin, Dr. A. Baceiredo
Laboratoire HØtØrochimie Fondamentale et AppliquØe, (UMR 5069)
UniversitØ Paul Sabatier
118 Route de Narbonne, 31062 Toulouse Cedex 09 (France)
Fax : (+33)561-558-204
In the 31P{1H} NMR spectrum, compound E1 displays an
AX system at dP =124 and 24 ppm (2JP,P =200 Hz) for the
E-mail: baceired@chimie.ups-tlse.fr
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8445

G. Bertrand, A. Baceiredo et al.
Scheme 2. Towards the synthesis of E1.
s3,l5-P and s4,l5-P atoms, respectively. In the 13C NMR spec-
trum, the quaternary carbon atoms appear as a doublet of
doublets at dC =93 ppm (JP, C =154 and 133 Hz), and as a
doubletat dC =27 ppm (JP, C =60 Hz). All these NMR signals
are strongly shifted to higher field compared to those for cu-
mulenes D[7] and bis(methylene)phosphoranes C.[6] Accord-
ing to a single-crystal X-ray diffraction study (Figure 1), the
Scheme 3. Reactivity of E1.
The corresponding C-phosphonio-bis(methylene)phosphor-
ane 5 was isolated in 84% yield. A single-crystal X-ray dif-
fraction analysis (Figure 2) confirms the regioselective alky-
lation at the C2 position. The central phosphorus atom (P1)
remains in a trigonal-planar environment (sum of the
À
angles: 359.58), with a short P1 C1 (163 pm) bond length,
Figure 1. Molecular view of the crystal structure of E1. H atoms are omit-
À
ted for clarity. Selected bond lengths [Š] and angles [8]: P1 C1
À
À
À
À
1.6725(13), P1 C2 1.6123(14), P1 N1 1.6597(10), P2 C2 1.6675(13), Si1
À
C1 1.8469(13), Si2 C1 1.8403(13); C2-P1-N1 113.59(6), C2-P1-C1
132.69(7), N1-P1-C1 113.40(6), P1-C1-Si2 117.20(7), P1-C1-Si1 121.85(7),
Si2-C1-Si1 120.95(7), P1-C2-P2 127.52(8).
s3,l5-phosphorus atom P1 is in a trigonal-planar environ-
À
ment(sum of ht e angles: 359.68 8), the P1 C1 (167 pm) and
À
P1 C2 (161 pm) bond lengths are short, and the C2-P1-C1-
Si2 dihedral angle is very pronounced (518). All these fea-
tures are very similar to those found in classical bis(methyle-
ne)phosphoranes C.[6] The P2-C2-P1 skeleton is also similar
to that of cumulenes of type D, with a P2-C2-P1 bond angle
Figure 2. Molecular view of the crystal structure of 5. The compound is
statistically mixed with an impurity, which is not represented. Triflate
anions and H atoms are omitted for clarity. Selected bond lengths [Š]
À
of 1278 and a shortP2 C2 bond length (167 pm).
Carbon C2 can be viewed as a dianionic center, since it is
part of the ylidic function and of the bis(methylene)phos-
phorane fragment, which is isoelectronic to an allylic anion.
Not surprisingly, a very clean alkylation reaction was ob-
served with methyl trifluoromethanesulfonate (Scheme 3).
À
À
À
À
and angles [8]: P1 C1 1.629(8), P1 N1 1.641(3), P1 C2 1.698(4), C1 Si2
À
À
À
1.878(7), C1 Si1 1.885(5), P2 C2 1.742(4), C2 C3 1.531(4); C1-P1-N1
120.1(3), C1-P1-C2 127.6(3), N1-P1-C2 111.73(16), P1-C1-Si2 118.7(3),
P1-C1-Si1 122.8(4), Si2-C1-Si1 118.0(4), C3-C2-P1 117.3(2), C3-C2-P2
118.3(2), P1-C2-P2 122.3(2).
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Chem. Eur. J. 2006, 12, 8444 – 8450

Extended Polyphosphacumulenes
FULL PAPER
which indicates that 5 has to be viewed as the first example
Since the dehydrofluorination could not be achieved, com-
pound 9’ was not characterized further. To prevent the ex-
change reaction, two equivalents of ylide 7 were used, and
of
a phosphonio-substituted bis(methylene)phosphorane.
This is confirmed by the 31P{1H} NMR spectrum, an AX
system at dP =+166 and +50 ppm (2JP, P =70 Hz) in the
range expected for both of these fragments.
Because the second carbon center is also nucleophilic,
compound E1 was expected to react as a “pincer”. Indeed,
the addition of one equivalent of a BF3·OEt2 led to the for-
mation of the novel four-membered heterocycle 6 with a be-
taine-like structure (Scheme 3). This compound results for-
mally from the substitution of a fluorine atom of BF3 by the
electron-rich C2 atom, followed by complexation of the
Lewis acid by the second carbon (C1) and addition of fluo-
ride to P1. Both enantiomers crystallized together from a
pentane/THF solution and their structures were obtained
from an X-ray diffraction study (Figure 3).[9]
The next goal was the synthe-
indeed the phosphino bis
A
yield. Treatment with CCl4 gave rise to the expected phos-
phonio bis(ylide) 9, although in low yield. The symmetry of
H
derivative 9 was indicated by an AX2 system in the 31P{1H}
2
NMR spectrum (dP =+63 (t) and +38 (d) JP, P =24 Hz), the
two ylidediyl fragments being equivalent. This was con-
firmed by the 13C NMR spectra, since the two ylidic carbon
atoms appeared as a single doublet of doublets at dC =30.3
(JP,C =52 and 73 Hz). A better method to prepare 9 is the
direct treatment of (diisopropylamino)dichlorophosphane
with three equivalents of ylide 7, followed by addition of
one equivalentof CCl . By this route 9 was isolated in 80%
4
yield (Scheme 4).
sis of longer cumulenes, and we
chose to prepare a derivative of
type F. First, based on the syn-
thetic strategy used for prepar-
ing E1, one equivalentof phos-
phorus ylide 7 was added to the
phosphonio phosphaalkene 2,
and the resulting adduct 8 was
treated
immediately
with
carbon tetrachloride. However,
as observed for the preparation
of 4, a halogen exchange occur-
red and the fluorinated phos-
phonio bis(ylide) 9’ was ob-
A
Scheme 4. Towards the precursor 9 of F1.
Finally, the desired 1s4,3s3,5s4-triphosphapenta-1,2,3,4-tet-
raene F1 was obtained by dehydrochlorination of the phos-
phonio bis
A
um hexamethyldisilazide (LiHMDS) (Scheme 5). Com-
Scheme 5. Synthesis of E1.
pound F1 was extracted with pentane and isolated as a
yellow powder after evaporation of the volatiles. All at-
tempts to obtain single crystals suitable for an X-ray diffrac-
tion study failed. However, the symmetrical cumulenic struc-
ture of F1 was established from the spectroscopic data. In
the 31P{1H} NMR spectrum the central s3,l5 phosphorus nu-
cleus appeared as a triplet at dP =+74 ppm (JP,P =107 Hz),
and the other two equivalent s4,l5 phosphorus centers as a
doubletat dP =+10 ppm (JP, P =107 Hz). As expected, these
chemical shifts are at higher field compared to those of the
corresponding “non-cumulenic” bis(methylene)phosphor-
Figure 3. Molecular view of the crystal structure of 6. Only one enan-
tiomer is represented. H atoms are omitted for clarity. Selected bond
À
À
À
lengths [Š] and angles [8]: P1 F1 1.6005(17), P1 N1 1.651(2), P1 C1
À
À
À
À
1.667(3), P1 C2 1.765(3), Si1 C2 1.896(3), Si2 C2 1.886(3), B1 C2
À
À
À
À
1.756(4), B1 C1 1.669(4), B1 F2 1.393(4), B1 F3 1.408(4), P2 C1
1.702(3); C1-P1-C2 94.49(14), C1-B1-C2 94.8(2), P1-C1-B1 88.15(18), P1-
C1-P2 135.03(18), B1-C1-P2 136.0(2), B1-C2-P1 82.44(17).
tained as shown by the 31P{1H} NMR (dP =+72, td, JP, P
=
30 Hz, JP,F =920 Hz; dP =+37, dd, JP, P =30 Hz, JP, F =13 Hz)
and 19F NMR spectra (dF =À66, td, JP, F =13 and 920 Hz).
Chem. Eur. J. 2006, 12, 8444 – 8450
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G. Bertrand, A. Baceiredo et al.
1s4,3s3-diphospha-1,2,3-butatriene E1: One equivalentof
hexane (2.7 mL, 4.3 mmol) was added, dropwise over a period of ten mi-
n-BuLi in
anes C and phosphonium ylides. Moreover, in the 31P NMR
spectrum, the signal for the s3,l5-P atom is a well-defined
triplet of triplets due to the additional large coupling con-
stant (3JP, H =18 Hz) with the two CH protons of the iPr2N
substituents. This unusual value is characteristic of a (diiso-
propylamino)bis(methylene) phosphorane moiety.[6] In addi-
nutes to
a
solution of bis(trimethylsilyl)dichloromethane (1.0 g,
4.3 mmol) in THF (10 mL)/Et2O (1 mL)/pentane (1 mL) at À1108C.
After the reaction mixture was stirred for 3 h at À1008C, a solution of
phosphonio phosphaalkene 2 (1.12 g, 2.17 mmol) in THF (5 mL) was
added dropwise. The mixture was allowed to warm up to À808C over a
period of 1.5 h, and then to room temperature. After evaporation of the
volatiles under vacuum, the residue was extracted with pentane, and
compound E1 was obtained as yellow crystals from the pentane solution
at4 8C. Yield 0.7 g (55%); m.p. 99–1018C; 31P{1H} NMR (C6D6): d= 124
and 24 ppm (JP, P =200 Hz); 1H NMR (C6D6): d= 0.23 (s, 18H; SiCH3),
1.10 (d, JH,H =6 Hz, 12H; CHCH3), 1.35 (d, JH,H =7 Hz, 12H; CHCH3),
1
tion, only one set of H and 13C NMR signals was observed
for the four phenyl groups, which is consistent with a trigo-
nal-planar geometry around the central phosphorus atom; it
must also be noted that the same groups are inequivalent in
the precursor 9, for which the central phosphorus atom is
prochiral. For the two quaternary carbon atoms, the ob-
3.79 (d sept, JH,H =6 Hz, 3JP, H =14 Hz, 2H; NCH), 4.58 (d sept, JH,H
7 Hz, JP, H =15 Hz, 2H; NCH), 7.18 (m, 6H; Haro), 7.98 ppm (m, 4H;
Haro); 13C{1H} NMR (C6D6): d= 3.0 (d, JP, C =22 Hz; SiCH3), 21.8 (s,
=
served chemical shift(pseudor-itplet
dC =52 ppm, JP, C =
160 Hz) also lies athigher field in comparison with E1.
CHCH3), 22.3 (s, CHCH3), 27.5 (d, JP, C =60 Hz; PCqSi), 45.6 (d, JP, C
=
In conclusion, we have synthesized, isolated and charac-
terized the first phosphacumulenes featuring a bis(methyle-
ne)phosphorane fragment. These compounds can be ob-
tained in good yields, through simple and short syntheses.
The generalization of the synthetic methodology to the
preparation of longer cumulen-
7 Hz, NCH), 47.4 (d, JP, C =7 Hz; NCH), 92.5 (dd, JP, C =154 and 133 Hz;
PCqP), 126.8 (s, CparaH), 128.9 (d, JP, C =2 Hz; CmetaH), 131.0 (d, JP,C
10 Hz; CorthoH), 133.5 ppm (dd, JP, C =101 and 8 Hz; CipsoH).
=
Phosphonio bis(methylene)phosphorane 5: Freshly distilled methyltri-
fluoromethanesulfonate (0.1 mL, 1.2 mmol) was added to a solution of
E1 (480 mg, 0.82 mmol) in pentane (5 mL) at À808C. After the mixture
was allowed to warm up to room temperature, a yellow solid appeared.
The solution was filtered and the resulting powder was washed with di-
ethyl ether (3”10 mL) and dried under vacuum. Crystals of 5, suitable
for an X-ray diffraction study, were obtained by layering Et2O over a sol-
ic molecules, featuring bis(me-
thylene)phosphorane fragments,
such as molecular wires of type
G, is currently under investiga-
ution of 5 in CH2Cl2 at room temperature. Yield 0.52 g (84%); m.p. 130–
2
1328C; 31P{1H} NMR (CDCl3): d= 166 (d, JP,P =70 Hz), 50 ppm (d, JP, P
=
70 Hz); 1H NMR (CDCl3): d=À0.06 (s, 9H; SiCH3), À0.04 (s, 9H;
SiCH3), 1.20 (d, JH,H =4 Hz, 12H; CHCH3), 1.25 (d, JH,H =8 Hz, 6H;
CHCH3), 1.27 (d, JH,H =7 Hz, 6H; CHCH3), 1.36 (d, JH,H =8 Hz, 6H;
CHCH3), 1.39 (d, JH,H =8 Hz, 6H; CHCH3), 2.02 (dd, JP, H =13 Hz and
tion.
Experimental Section
20 Hz, 3H; PC(CH3)P), 3.84 (broad, 4H; NCH), 4.30 (broad, 2H; NCH),
A
7.62 (m, 6H; Haro), 7.73 ppm (m, 4H; Haro); 13C{1H} NMR (CDCl3):?d=
2.6 (d, JP, C =6 Hz; SiCH3), 3.6 (d, JP, C =6 Hz; SiCH3), 22.0 (dd, JP, C =8
and 54 Hz; H3CCP), 24.2 (s, H3CCN), 24.2 (s, H3CCN), 24.7 (s, H3CCN),
25.6 (s, H3CCN), 34.4 (dd, JP, C =47 and 54 Hz; PCP), 49.1 (broad, HCN),
General remarks: All manipulations were performed under an inert at-
mosphere of argon using standard Schlenk techniques. Dry, oxygen-free
solvents were employed. Tetrachloromethane was dried by elution
through a dry basic alumina column. 1H, 13C, and 31P NMR spectra were
recorded on Varian Inova 300 and 500, and Bruker Avance 300 spectrom-
49.4 (d, JP, C =5 Hz; HCN), 74.6 (d, JP, C =80 Hz; PCSi), 129.3 (d, JP, C
=
12 Hz; CHaro), 131.0 (dd, JP,C =10 and 102 Hz; Caro), 132.9 (d, JP, C =11 Hz;
CHaro), 134 ppm (s, CHaro).
1
eters. H and 13C chemical shifts are reported in ppm relative to Me4Si as
external standard. 31P NMR downfield chemical shifts are expressed with
a positive sign, in ppm, relative to external 85% H3PO4. 19F chemical
shifts are reported in ppm relative to FCCl3 as external standard.
Four-membered heterocycle 6: A stoichiometric amount of BF3·Et2O was
added to a solution of E1 in hexane at À788C. The resulting mixture was
stirred at room temperature for 2 h. A solid precipitated. After filtration,
the yellow powder was dried under vacuum, and recrystallized from a
pentane/THF mixture at À308C. Heterocycle 6 was obtained as yellow
crystals. Yield 0.5 g (65%); m.p. 77–758C; 31P{1H} NMR ([D8]THF): d=
74 (d broad, JP,F =1090 Hz), 32 ppm (broad); 19F NMR ([D8]THF): d=
À48 (d broad, JP, F =1090 Hz), À67 ppm (broad); 1H NMR ([D8]THF):
d= À0.31 (s, 9H; SiCH3), À0.20 (s, 9H; SiCH3), 0.37 (d, JH,H =6 Hz, 6H;
NCCH3), 0.64 (d, JH,H =7 Hz, 6H; NCCH3), 0.71 (d, JH,H =6 Hz, 6H;
NCCH3), 0.89 (d, JH,H =6 Hz, 6H; NCCH3), 3.25 (m, 2H; NCH), 3.82
Bis(ylide) 4’: One equivalentof n-BuLi in hexane (1.35 mL, 2.15 mmol)
A
was added dropwise over a period of ten minutes to a solution of bis(tri-
methylsilyl)dichloromethane (0.5 g, 2.15 mmol) in THF (5 mL)/Et2O
(1 mL)/pentane (1 mL) at À1108C. After the reaction mixture was stirred
for 3 h at À1008C, a solution of phosphonio phosphaalkene 2 (1.12 g,
2.17 mmol) in THF (5 mL) was added dropwise. The mixture was al-
lowed to warm up to À808C over a period of 1.5 h, and then to room
temperature. After evaporation of the volatiles under vacuum, the resi-
due was extracted with pentane, and derivative 4’ was obtained as yellow
crystals in 51% yield from the pentane solution at À308C. m.p.: 112–
1148C; 31P{1H} NMR (C6D6): d= 83 (dd, JP, P =26 Hz), JP, F =910 Hz),
38 ppm (dd, JP, P =26 Hz, JP, F =12 Hz); 19F NMR (C6D6): d= À71 ppm (d
broad, 1JP, F =910 Hz); 1H NMR (C6D6) d= 0.29 (s, 9H; SiCH3), 0.46 (s,
(septbroad,
JH,H =6 Hz, 2H; NCH), 7.10 (m, 4H; Haro), 7.46 ppm (m,
6H; Haro); 13C{1H} NMR ([D8]THF): d= 4.2 (s, SiCH3), 4.8 (s, SiCH3),
24.4 (s, NCCH3), 24.6 (s, NCCH3), 24.9 (d, JP, C =3 Hz, NCCH3), 25.0 (s,
NCCH3), 48.6 (d, JP, C =8 Hz, NCH), 49.0 (d, JP, C =5 Hz, NCH), 128.6
(pseudo t, JP,C =10 Hz; CHaro), 129.3 (d, JP, C =11 Hz; CHaro), 129.6 (d,
J
P, C =10 Hz; CHaro), 129.6 ppm (dd, JP,C =52 Hz and 5 Hz; Caro).
3
9H; SiCH3), 1.01 (d, JH,H =6 Hz, 6H; CHCH3), 1.03 (d, JH,H =6 Hz, 6H;
Addition of phosphorus ylide 7 (1 equiv) to phosphonio phosphaalkene
2: One equivalentof phosphorus ylide 7 was added to a solution of 2 in
THF at À788C. After warming to room temperature, the mixture was
stirred for 1 h. The solvent was removed under vacuum and the residue
was washed with ether and dried under vacuum to give 8 in about80%
purity. 31P{1H} NMR: d= 50 (d, JP, P =90 Hz), 39 (d, JP, P =184 Hz), 20 ppm
CHCH3), 1.17 (d, JH,H =7 Hz, 6H; CHCH3), 1.20 (d, JH,H =7 Hz, 6H;
CHCH3), 1.49 (dd, JP, H =11 Hz and 4 Hz, 1H; PCHP), 3.95 (sept, JH,H
=
7 Hz, 2H; NCH), 4.40 (d sept, JH,H =6 Hz, JP, H =12 Hz, 2H; NCH), 7.10
(m, 4H; Haro), 7.81 ppm (m, 6H; Haro); 13C{1H} NMR (C6D6): d= 5.9 (s,
SiCH3), 15.9 (dd, JP, C =127 Hz, JC,F =17 Hz; PCSi), 16.4 (ddd, JP, C =132
and 162 Hz, JC,F =27 Hz; PCHP), 24.1 (s, CHCH3), 24.3 (s, CHCH3), 25.2
(s, CHCH3), 47.0 (broad, NCH), 48.5 (d, JP, C =6 Hz, NCH), 128.6 (s,
(dd, JP,P =90 and 184 Hz). One equivalentof CCl was then added to a
4
solution of 8 in THF at À788C. After the mixture had been warmed to
room temperature, multinuclear NMR spectroscopy indicated the quanti-
tative formation of the fluorinated derivative 9’. 31P{1H} NMR
C
aroH), 131.4 (d, JP, C =9 Hz; CaroH), 133.1 (s, CaroH), 133.0 (d, JP, C
=
18 Hz; CaroH), 132.1 ppm (d, JP, C =25 Hz; Cipso).
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Chem. Eur. J. 2006, 12, 8444 – 8450

Extended Polyphosphacumulenes
FULL PAPER
([D8]THF): d= 72 (td, JP, P =30 Hz, JP, F =920 Hz), 37 ppm (dd, JP, P
=
flections for E1 and 6) and integrated by using the Bruker SAINTPLUS
software package.[14b] The intensity data were corrected for Lorentzian
polarization, and absorption corrections were performed by using the
SADABS program incorporated in the SAINTPLUS software package.
The Bruker SHELXTL software package[14c] was used for directmeht ods
of phase determination and structure refinement. Atomic coordinates, as
well as isotropic and anisotropic displacement parameters of all the non-
hydrogen atoms of the three compounds were refined by means of a full-
matrix least-squares procedure on F2. All H atoms were included in the
refinement in calculated positions riding on the atoms to which they
were attached. E1: dimensions 0.46”0.40”0.18 mm3, triclinic, space
30 Hz, JP, F =13 Hz); 19F NMR ([D8]THF): d= À66 ppm (td, JP,F =13 and
920 Hz).
Addition of phosphorus ylide 7 (2 equiv) to phosphonio phosphaalkene
2: Two equivalents of phosphorus ylide 7 were added to a solution of 2 in
THF at À788C. After warming up to room temperature, the mixture was
stirred overnight. The solvent was removed under vacuum and the prod-
uct was extracted with pentane. The evaporation of the volatiles afforded
10 as an orange oil; 31P{1H} NMR (C6D6): d= 7.0 (dd, JP, P =147 and
154 Hz), 29.9 (d,
JP, P =147 Hz), 29.9 ppm (d, J
P, P =154 Hz); 1H NMR
(C6D6): d= 1.03 (d, JH,H =7 Hz, 6H; H3CCN), 1.11 (d, JH,H =6 Hz, 12H;
H3CCN), 2.0 (dd, JP, H =6 and 2 Hz, 2H; PCHP), 3.66 (d sept, JH,H =6 Hz,
¯
group P1, a=9.2941(7), b=10.6288(8), c=19.6356(15) Š, a=84.765(2)8,
b=83.516(2)8, g=68.7100(10)8, V=1793.1(2) Š3, 1calcd =1.087 gcmÀ3
2qmax =56.568, Mo radiation (l=0.71073 Š), low temperature=223(2) K,
total reflections collected=18601, independentreflecitons =8853 (Rint
,
J
P, H =9 Hz, 2H; HCN), 3.78 (sept, JH,H =7 Hz, 4H; HCN), 7.1 (m, 12H;
Haro), 7.2 (m, 4H; Haro), 7.8 ppm (m, 4H; Haro); 13C{1H} NMR (C6D6):
d= 23.7 (s, H3CCN), 23.9 (s, H3CCN), 24.0 (s, H3CCN), 24.1 (s, H3CCN),
30 (dt, JP, C =18 and 124 Hz; PCP), 45.4 (d, JP, C =9 Hz; HCN), 46.2 (d,
=
0.0210, Rsig =0.0252), 7714 (87.2%) reflections were greater than 2s(I),
index ranges À12ꢀhꢀ12, À14ꢀkꢀ13, À26ꢀlꢀ26, absorption coeffi-
cient m=0.210 mmÀ1; max/min transmission=0.9632/0.9096, 410 parame-
ters were refined and converged at R1=0.0393, wR2=0.1102, with inten-
sity I>2s(I), the final difference map was 0.455/À0.238 eŠÀ3. 5: dimen-
sions 0.38”0.21”0.13 mm3, monoclinic, space group P2(1)/c, a=
J
P, C =4 Hz; HCN), 127.0 (s, CHaro), 127.2 (s, CHaro), 128.8 (s, CHaro), 129.3
(s, CHaro), 132.1 (d, JP, C =8 Hz; CHaro), 133.2 (d, JP, C =8 Hz; CHaro),
135.3 ppm (dd, JP, C =3 and 110 Hz; Caro).
Addition of phosphorus ylide 7 (3 equiv) to dichlorodiisopropylamino-
phosphine: The aminodichlorophosphine (1.45 mL, 8 mmol) was added
to a solution of phosphorus ylide 7 (24 mmol) in THF (20 mL) at À788C.
After warming to room temperature, the solution was stirred overnight.
The solution was filtered and the product was extracted from the solid
residue with THF (3”20 mL). The volatiles of the combined THF solu-
tions were removed under vacuum. The resulting white powder was
washed with diethyl ether (3”30 mL) and dried under vacuum. This
sample contained a small amount of methyl(diisopropylamino)diphenyl
phosphonium chloride, but can be used without any further purification.
8: Yield: 6.0 g (80%); the 31P NMR data are identical to those described
above for the tetrafluoroborate salt.
11.055(2),
b=20.816(4),
c=18.375(4) Š,
b=98.323(5)8,
V=
4183.9(15) Š3, 1calcd =1.199 gcmÀ3
,
2qmax =56.568, Mo radiation (l=
0.71073 Š), low temperature=218(2) K, total reflections collected=
58364, independentreflecitons =10386 (Rint =0.0451, Rsig =0.0316), 7624
(73.4%) reflections were greater than 2s(I), index ranges À14ꢀhꢀ14,
À27ꢀkꢀ27, À24ꢀlꢀ24, absorption coefficient m=0.258 mmÀ1; max/
min transmission=0.9672/0.9082, 841 parameters were refined and con-
verged at R1=0.0540, wR2=0.1431, with intensity I>2s(I), the final dif-
ference map was 0.353/À0.208 eŠÀ3. 6: dimensions 0.48”0.22”0.03 mm3,
¯
monoclinic, space group P1, a=9.8703(9), b=16.1740(14), c=
23.333(2) Š, a=86.084(2)8, b=80.160(2)8, g=88.468(2)8, V=
3661.1(6) Š3, 1calcd =1.188 gcmÀ3
2qmax =49.428, Mo radiation (l=
Synthesis of the phosphonio bis(ylide) 9: A suspension of 8 (2.8 g,
G
,
3.7 mmol) in THF (30 mL) was stirred vigorously at room temperature,
and freshly dried CCl4 (0.5 mL, 5 mmol) was added dropwise. After 30
minutes, the volatiles were removed under vacuum. The resulting yellow
powder was washed with Et2O (3”20 mL) and dried under vacuum.
Yield: 2.5 g (84%); 31P{1H} NMR (CDCl3): d= 63 (t, JP,C =24 Hz),
0.71073 Š), low temperature=223(2) K, total reflections collected=
28876, independentreflecitons =12490 (Rint =0.0457, Rsig =0.0690), 8268
(66.2%) reflections were greater than 2s(I), index ranges À11ꢀhꢀ11,
À19ꢀkꢀ19, À27ꢀlꢀ27, absorption coefficient m=0.223 mmÀ1 max/min
;
transmission=0.9933/0.9004, 897 parameters were refined and converged
at R1=0.0490, wR2=0.1173, with intensity I>2s(I), the final difference
map was 0.378/À0.304 eŠÀ3. CCDC-610973 (E1), CCDC-610974 (5), and
CCDC-610975 (6) contain the supplementary crystallographic data for
this paper. These data can be obtained free of charge from the Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_re-
quest/cif.
1
38 ppm (d, JP, C =24 Hz); H NMR (CDCl3): d= 0.91 (d, JH,H =7 Hz, 12H;
H3CCN), 0.94 (d, JH,H =7 Hz, 12H; H3CCN), 1.05 (d, JH,H =7 Hz, 12H;
H3CCN), 1.44 (dt, JP, H =2 and 7 Hz, 2H; PCHP), 3.53 (pseudo oct, JP, H
=
J
H,H =7 Hz, 4H; HCN), 3.75 (d sept, JP, H =9 Hz, JH,H =7 Hz, 2H; HCN),
7.46 (m, 10H; Haro), 7.64 (m, 5H; Haro), 7.82 ppm (m, 5H; Haro); 13C{1H}
NMR (CDCl3): d=22.6 (d, JP, C =4 Hz; H3CCN), 23.2 (s, H3CCN), 30.3
(dd, JP, C =52 and 73 Hz; PCP), 47.8 (d, JP, C =6 Hz; HCN), 48.2 (d, JP, C
=
3 Hz; HCN), 127.3 (dd, JP, C =3 and 58 Hz; Caro), 128.2 (d, JP, C =11 Hz;
HCaro), 128.7 (dd, JP,C =3 and 57 Hz; Caro), 128.7 (d, JP, C =13 Hz; CHaro),
129.5 (d, JP,C =14 Hz; CHaro), 130.0 (d, JPC =14 Hz; CHaro), 130.4 (d, JP,C
=
12 Hz; CHaro), 132.4 (s, CHaro), 132.6 (s, CHaro), 133.1 (d, JP, C =11 Hz;
CHaro), 134.0 ppm (d, JP,C =13 Hz; CHaro).
Acknowledgement
1s4,3s3,5s4-triphosphapenta-1,2,3,4-tetraene F1: Two equivalents of
a
We are grateful to the CNRS for financial support of this work.
LiHMDS solution (1.2 g, 5 mmol) in THF (10 mL) was added at À788C
to a suspension of bis-ylide 9 (2.0 g, 2.5 mmol) in THF (20 mL). After
the mixture was allowed to warm to room temperature, the volatile mate-
rials were removed under vacuum, and the residue was extracted with
pentane. Derivative F1 precipitated from a concentrated pentane solution
at À308C as a yellow powder. Yield 1.12 g (62%); 31P NMR (C6D6): d=
74 (tt, JP, P =107 Hz, JP,H =18 Hz), 10 ppm (d, JP, P =107 Hz); 1H NMR
(C6D6): d= 1.16 (d, JH,H =7 Hz, 24H; H3CCN), 1.34 (d, JH,H =6 Hz, 12H;
H3CCN), 3.68 (d sept, JP,H =15 Hz, JH,H =7 Hz, 4H; HCN), 4.33 (d sept,
[1] See for example: a) B. Bildstein, M. Schweiger, H. Angleitner, H.
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P, H =18 Hz, JH,H =6 Hz, 2H; HCN), 7.08 (m, 8H; Haro), 7.78 ppm (m,
12H; Haro); 13C{1H} NMR (C6D6): d= 23.6 (s, NCCH3), 24.2 (s, NCCH3),
47.3 (d, JP, C =6 Hz; NCH), 47.5 (d, JP, C =8 Hz; NCH), 51.1 (t, JP,C
160 Hz; PCP), 128.0 (d, JP, C =12 Hz; CHaro), 129.4 (s, CHaro), 132.8 (d,
P, C =12 Hz; -CHaro), 138.4 ppm (dd, JP,C =100 and 4 Hz; Caro).
=
[3] Other cumulenes based on carbon and phosphorus are known, but
À
they contain C C double bonds, see for example: a) G. Märkl, P.
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data collection of compounds E1, 5, and 6. All data frames were collect-
ed by using the w-scan mode (hemisphere reflections for 5, sphere of re-
Chem. Eur. J. 2006, 12, 8444 – 8450
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
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Received: June 13, 2006
Published online: September 29, 2006
8450
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 8444 – 8450