Nucleophilic phosphanylation of fluoroaromatic compounds with carboxyl, carboxymethyl, and aminomethyl functionalities - An efficient synthetic route to amphiphilic arylphosphanes

Article abstract of DOI:10.1002/(SICI)1099-0682(199801)1998:1<73::AID-EJIC73>3.0.CO;2-M

Chiral- and multiply-carboxylated phosphanes and phosphanyl derivatives of benzoic and phthalic acids (1-9) are accessible in high yields by nucleophilic phosphanylation of potassium or lithium salts of commercially available fluorobenzoic and 3-fluorophthalic acids with Ph₂PH, Ph₂PK, PhPLi₂, Ph(K)P-(CH₂)₃-P(K)Ph in superbasic media (DMSO/KOH) or in THF and DME. The hitherto unknown phosphanylphenylacetic acids (10-13) and phosphanylbenzylamines RR′P-C₆H₄-CH₂-NH₂ (14-19, R, R′ = H, Me, Ph) with unsubstituted amino groups were also synthesized by this method. The diphenylphosphanyl derivatives 14-16 (R, R′ = Ph) are accessible by an alternative method involving LiAlH₄ reduction of the phosphanylbenzonitriles (20-22), which were obtained in high yields by nucleophilic phosphanylation of the corresponding fluoro- or chlorobenzonitriles. The novel bidentate phosphanylbenzonitrile 23 has also been obtained using this synthetic route. All compounds were completely characterized by elemental analysis, NMR spectroscopy, and mass spectrometry.

Full text of DOI:10.1002/(SICI)1099-0682(199801)1998:1<73::AID-EJIC73>3.0.CO;2-M

FULL PAPER
Water Soluble Phosphanes, IX[᭛]
Nucleophilic Phosphanylation of Fluoroaromatic Compounds with Carboxyl,
Carboxymethyl, and Aminomethyl Functionalities ؊ an Efficient Synthetic
Route to Amphiphilic Arylphosphanes
Martin Hingst, Michael Tepper, and Othmar Stelzer*
Fachbereich 9, Anorganische Chemie, Bergische Universität-GH Wuppertal,
D-42097 Wuppertal, Germany
Received May 6, 1997
Keywords: Nucleophilic phosphanylation / Phosphanylphthalic acid / Phosphanylphenylacetic acid /
Benzylaminophosphanes / Water solubility
Chiral- and multiply-carboxylated phosphanes and phospha- method. The diphenylphosphanyl derivatives 14Ϫ16 (R, RЈ =
nyl derivatives of benzoic and phthalic acids (1Ϫ9) are acces- Ph) are accessible by an alternative method involving LiAlH4
sible in high yields by nucleophilic phosphanylation of potas- reduction of the phosphanylbenzonitriles (20Ϫ22), which
sium or lithium salts of commercially available fluorobenzoic
and 3-fluorophthalic acids with Ph2PH, Ph2PK, PhPLi2, tion of the corresponding fluoro- or chlorobenzonitriles. The
Ph(K)PϪ(CH2)3ϪP(K)Ph in superbasic media (DMSO/KOH) novel bidentate phosphanylbenzonitrile 23 has also been ob-
or in THF and DME. The hitherto unknown phosphanylphe- tained using this synthetic route. All compounds were com-
were obtained in high yields by nucleophilic phosphanyla-
nylacetic acids (10Ϫ13) and phosphanylbenzylamines
RRЈPϪC6H4ϪCH2ϪNH2 (14Ϫ19, R, RЈ = H, Me, Ph) with un-
substituted amino groups were also synthesized by this
pletely characterized by elemental analysis, NMR spectros-
copy, and mass spectrometry.
Aromatic phosphanes with carboxylated side chains, e.g. dition, the carboxylate substituents are connected in a more
Ph2PϪ(CH2)nϪCOOH, Ph2PϪC6H4Ϫ2-COOH, have been flexible manner to the rigid aromatic ring systems. For the
extensively employed as components in catalysts for the oli- sake of comparison we have included phosphanylbenzylam-
gomerization, polymerization, telomerization and hydrofor- ines C in our study, and these systems contain aminomethyl
mylation of olefins[2a][2b][2c][2d]. Thus, the catalyst used for groups. These groups can be protonated to give novel cat-
the two phase oligomerization of olefins in the “Shell higher ionic water soluble phosphanes D. Ligands of this type,
olefin process” (SHOP)[2e] is prepared by reaction of bis- bearing quaternary ammonium groups, form palladium
(cyclooctadiene)nickel(0) with diphenylphosphanylacetic complexes with phase transfer properties. They are effective
acid. Reduction/substitution reactions performed on per- catalysts for the fluorocarbonylation of bromobenzene with
technate leads to neutral technetium(III) complexes with CO and KF[4b]
carboxylated phosphanes in which the phosphane ligands
.
act as O,P-bidentate systems. The biodistribution of the
corresponding 99mTc labelled species has been studied[2f]
.
The o-, m-, and p-isomers of diphenylphosphanylbenzoic
acid have been reported earlier. These compounds are ac-
cessible by multistep[3a][3b][3c] or protective group syn-
thesis[3d], but only in moderate overall yields. Despite the
keen interest in these ligands, there are no reports in the
literature so far on their higher carboxylated analogs (A) or
derivatives containing CH2 spacers between the aromatic
ring and the COOH-groups (“phosphanylphenylacetic ac-
ids” B). Compounds of type A, which contain an additional
set of hard donor atoms, should show enhanced solubility
in water, and both of these factors are important for the
application of these ligands in two-phase catalysis[4]. Li-
gands of type B contain activated CH2 groups and, in ad-
Ligands with functionalized peripheries are of increasing
interest[5a] because of their potential for further derivatiz-
ation, e.g. by esterification with diols to give functionalized
linear polymers suitable as insoluble supports for the immo-
bilization of catalysts[5b]
.
As part of a project aimed at the development of tailor
made water soluble phosphanes[6] for two-phase catalysis
we have developed new synthetic procedures for these li-
gands based on nucleophilic phosphanylation of suitable
functionalized fluoro-aromatic compounds under different
conditions.
Part VIII: Ref.[1]
.
[᭛]
Eur. J. Inorg. Chem. 1998, 73Ϫ82
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1998
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73

M. Hingst, M. Tepper, O. Stelzer
FULL PAPER
Nucleophilic Phosphanylation of Fluorobenzoic and
Fluorophthalic Acids
subsequent dealkylation of the intermediate Me2S with
Ph2PK[10] (eq. 3a,b). The potassium salt of m-fluorobenzoic
acid did not react with Ph2PH under these conditions. The
COOK substituent in the m-position clearly does not acti-
vate the fluorine sufficiently for nucleophilic displacement
to occur under these conditions.
Nucleophilic displacement of the halogen (X) in aromatic
compounds XϪC6H4ϪZ (X ϭ F, Cl, Br; Z ϭ NO2, SO3H,
COOH) that contain electron withdrawing substituents (Z),
proceeds much faster with the fluoro- than with the chloro-
or bromo-compounds. This is well established for the
halonitrobenzenes[7a][7b] and a variety of substituted aro-
matic amines has been obtained by making use of the pro-
nounced reactivity of activated fluorobenzene derivatives
towards nitrogen nucleophiles[7c]. The phosphanylation of
the commercially available fluorobenzoic or fluorophthalic
acids should in an analogous way lead to phosphanylben-
zoic or phosphanylphthalic acids. This transformation can
be performed in “superbasic” media[8], using secondary or
primary phosphanes and solid KOH as the base in aprotic
dipolar solvents (e.g. dimethyl sulfoxide). Alternatively, al-
kali metal phosphides such as Ph2PK or PhPLi2 can be em-
ployed for these nucleophilic aromatic substitution reac-
tions in solvents like 1,2-dimethoxyethane (DME) or tetra-
hydrofuran (THF).
If
a solution of Ph2PK in THF is used, then
2-FϪC6H4ϪCOOK could be phosphanylated to give
the phosphane 1 in fair yield (eq. 1b). The m-isomer
3-FϪC6H4ϪCOOK, however, did not react at all even after
prolonged reaction times. This might, at least in part, be
due to the fact that 3-FϪC6H4ϪCOOK could not be ob-
tained in a completely anhydrous form. 3-FϪC6H4ϪCOOK
and 2-FϪC6H4ϪCOOK were prepared by neutralization of
the corresponding acids with KOH in aqueous solution and
heating the hydrates left after evaporation of water in vacuo
at 100Ϫ120 °C for a couple of hours. The use of the an-
hydrous lithium salt 3-FϪC6H4ϪCOOLi instead of
3-FϪC6H4ϪCOOK resulted in phosphanylation with
Ph2PK in THF to afford 2 after work up of the reaction
mixture (eq. 1c). Anhydrous 3-FϪC6H4ϪCOOLi can be
obtained by deprotonation of the free acid with nBuLi or,
[11]
preferably, LiN(SiMe3)2
.
The bis(carboxyphenyl)phosphanes 5Ϫ7 are accessible, in
an analogous way to that described above, by phosphanyl-
ation of the lithium salts of the corresponding fluoroben-
zoic acids with PhPLi2 in THF (eq. 1e). In the case of the
m-isomer of F-C6H4ϪCOOLi, the nucleophilic aromatic
substitution proceeds much slower than the corresponding
reaction with the p- and o-isomers. This can be understood
in terms of the different stabilization of the Meisenheimer
type intermediate E[7b] by the COOH/COOϪ-substituents
in the m- or p- and o-position to the fluoro substituent. The
synthetic procedure developed for 5Ϫ7 can be extended to
phthalic acid derivatives. Thus, nucleophilic phosphanyl-
ation of the Li-salt of 3-fluorophthalic acid with Ph2PK or
PhPLi2 gave 4 or 8 after an acid workup procedure (eq.
1d,f). In the same way, Ph(K)PϪ(CH2)3ϪP(K)Ph was
treated with 3-FϪC6H3Ϫ1,2-(COOLi)2 to yield the chiral
bidentate tetracarboxylated phosphane 9 (eq. 1g).
The potassium salts of the phthalic acid derivatives ob-
The nucleophilic phosphanylation of p-fluorobenzoic tained by neutralization of 4, 8, and 9 with KOH are highly
acid with Ph2PH in the superbasic medium at 60 °C af- soluble in water [0.8, 1.3, and 1.0 kg/kg water (20 °C),
forded the potassium salt of the phosphane 3 in a straight- respectively].
forward manner (eq. 1a). However, the corresponding reac-
Very recently we have found that carboxylated phos-
tion with the o-isomer gave only poor yields of 1. Diphenyl- phanes (1Ϫ7) including salicylic, isophthalic, and anthra-
phosphane oxide Ph2P(H)O[9a] and Ph2PMe[9b] are formed nilic acid derivatives (FϪH) can alternatively be synthesized
by oxidation of Ph2PH (Ph2PK) with DMSO followed by by Pd-catalyzed PϪC coupling reactions between primary
74
Eur. J. Inorg. Chem. 1998, 73Ϫ82

Water Soluble Phosphanes, IX
FULL PAPER
or secondary phosphanes and the corresponding func- loyl chloride[5a]. A new method for preparing water-soluble
tionalized iodo- or bromo-aromatic compounds[1,12]
.
phosphanes by coupling of the phosphanylbenzylamine
The electron impact mass spectra of the phosphane li- Ph2PϪC6H4ϪCH2Ϫ4-NH(Me) to polyacrylic acid has very
gands with monocarboxylated phenyl groups (1Ϫ3, 5Ϫ7) recently been reported[18]. Attempts to prepare phosphanyl-
all show the Mϩ peak. Proximity effects[13] in the molecular benzylamines with a primary amino group by protective
ions of the o-carboxylated phosphanes (1, 5) lead to the loss group synthesis via their 2,5-dimethylpyrrole derivatives or
of CHO from the molecular ion. In the case of the phthalic stabase (cyclic disilazane) adducts have so far been unsuc-
acid derivatives 4, 8, and 9, the peaks of highest m/z corre- cessful[5a]
.
spond to ions formed by loss of one or two molecules of
H2O.
We found, however, that phosphanylbenzylamines are ac-
cessible in a straightforward manner using a procedure
analogous to that employed for the synthesis of the phos-
phanylphenylacetic acids 10Ϫ13. Thus, reaction of o-, m-,
or p-fluorobenzylamine with Ph2PK in DME produced the
phosphanes 14Ϫ16 in good yields. Chiral tertiary (17 and
18) and even secondary phosphanylbenzylamines (19) are
accessible by this synthetic route if Ph(Me)PK or PhPHK
Synthesis of Phosphanylphenylacetic Acids
The multiple functionality of the CH2ϪCOOR(H) group
means that phosphanylphenylacetic acids and their esters
should show an extended reactivity pattern (e.g. ester con-
densation) in comparison with benzoic and phthalic acid
phosphanes of type 1؊8. This can be used for the design of
tailor-made ligands with chiral backbones by the modular
approach, as reported by Trost, van Vrancken and
are used instead of Ph2PK (eq. 3a,b)[15]
.
Bingel[14]
.
Nucleophilic phosphanylation of fluorophenylacetic ac-
ids in dimethoxyethane (DME) was employed for the syn-
thesis of phosphanylphenylacetic acids. The intermediate of
type E, formed in the rate determining step of these
SN2(Ar) processes, cannot be stabilized by the mesomeric
effects of the substituents, and so the nucleophilic replace-
ment is expected to proceed much slower than the anal-
ogous reaction of the fluorobenzene derivatives
FϪC6H4ϪZ [Z ϭ CN (see below), COOϪ, SO3Ϫ] with acti-
vating substituents. The weakly electron-withdrawing
CH2COOϪ group can only activate the CϪF bond in the
ortho position due to its inductive effect. Thus, the reaction
of the potassium salts of o- or p-fluorophenylacetic acid
with Ph2PK in DME requires 24 h reflux to give the re-
spective isomers of diphenylphosphanylphenylacetic acid
(10, 11), after acidification of the reaction mixtures, in satis-
factory yields (eq. 2). The P-chiral derivatives (12, 13) can
be prepared in an analogous way using Ph(Me)PK instead
of Ph2PK. Potassium fluorophenylacetate (o- or p-isomer)
was obtained by neutralization of the appropriate free acids
with a solution of KOH in methanol, followed by heating
the solid left after evaporation of the solvent in vacuo (60
°C, 0.01 mbar)[15]
.
The phosphanylbenzylamines 14 and 15 have been syn-
thesized using an alternative route involving reduction of
the cyanophenylphosphanes 20 and 21[3b][3c][19] with Li-
AlH4. The cyanophenylphosphanes are attractive starting
materials since they can be obtained by a convenient
method and in high yields by direct phosphanylation of the
corresponding fluoro- or chlorobenzonitriles with Ph2PH in
the superbasic medium DMSO/KOH (eq. 3c,d). The same
applies for the m-isomer 21. Somewhat lower yields of the
cyanophenylphosphanes (20Ϫ22) are obtained if the phos-
phanylation of the halobenzonitriles are performed with
Ph2PK in THF (eq. 3e). In both cases the nucleophilic aro-
The molecular ion peaks in the mass spectra of the phos-
phanylphenylacetic acids are of high intensity (10) or rep-
resent the base peaks (11Ϫ13). The fragmentation pathway
leads to the 9-phosphafluorenylium ions[16][17] at m/z ϭ 183
or 197.
The solubilities of the alkali metal salts of the p-diphenyl-
phosphanylphenylacetic acids in water (20 °C) are signifi-
cantly higher than those of the corresponding o-isomers
(e.g. Naϩ 10: 130; Naϩ 11: 750 g/kg water).
Synthesis of Phosphanylbenzylamines
Phosphanylbenzylamines with a primary amino group matic substitution proceeds almost instantaneously, even at
are of interest as starting materials for the synthesis of poly- room temperature or below. The synthesis of the cyano-
merizable phosphanes by acylation with acryl- or methacry- phenylphosphanes 20Ϫ22 according to eq. 3c is therefore
Eur. J. Inorg. Chem. 1998, 73Ϫ82
75

M. Hingst, M. Tepper, O. Stelzer
FULL PAPER
superior to the methods reported in the literature[3b][3c][19]
.
31P{1H}-NMR shift values of 14Ϫ17 on protonation with
o-Cyanophenyldiphenylphosphane (20) was obtained by HCl are very small, indicating that the addition of the pro-
nucleophilic phosphanylation of 2-FϪC6H4ϪCN according ton occurs preferentially at the nitrogen atom. The same
to eq. 3c and 3e in a straightforward manner. However, at- also applies in the case of the 13C{1H}-NMR data (c.f. 17/
tempts to synthesize this ligand by reaction of 2- 17a), with the exception of δC(2)(CϪCH2ϪNH2) (17:
ClϪC6H4ϪCN with Ph2PM (M ϭ Li, K) gave only very 147.0, 17a: 138.6) (Table 2).
poor yields[19]. This clearly demonstrates the greater reac-
The assignment of the 13C{1H}-NMR signals of 1Ϫ23
tivity of aromatic CϪF bonds towards nucleophiles in com- (Table 2; for the numbering scheme of the carbon atoms see
parison with CϪCl bonds[7].The p-isomer (22) could, how- Figure 1a) was achieved by comparison of the 13C-shift val-
ever, be obtained from 4-chlorobenzonitrile, indicating that ues with those found in a series of related compounds in-
the steric influence of the o-substituents may be decisive cluding Ph3P[21], Ph2PH and PhPH2[22]. The assignments
and override the important electronic effects. In the case of were further substantiated by analysis of the proton-cou-
the reactive 2,5-difluorobenzonitrile, both fluoro-substitu- pled spectra, including DEPT spectra[23], and comparison
ents in the o-positions can be replaced by the bulky Ph2P- of the relative intensities of the signals. Further support for
substituents on reaction with Ph2PK, with the interesting a correct assignment comes from the relative magnitude of
bidentate ligand 23 being formed in high yield (eq. 3g).
the coupling constants nJ(PC), which generally decrease
2
1
2
3
Protonation of 14Ϫ18 at the amino group gives cationic within the series J(PC) > J(PC) and J(PC) > J(PC) >
phosphanes (14aϪ18a) (eq. 3f), and the water solublities of 4J(PC)[23]. The 13C-NMR spectra could be analyzed using
these compounds range from 5 to 970 g per kg of water at a first order approximation with 2J(CH) < 3J(CH) and
20 °C. The p-isomers have much higher solubilities than the 4J(CH) ca. 0 Hz[23]. This is shown for 8 as a representative
corresponding ortho-compounds. At higher temperatures example in Figure 1c.
thermal dissociation occurs to give the primary amines and
The introduction of one COOH, CH2ϪCOOH, or
HCl. The mass spectra obtained from 14aϪ18a therefore CH2ϪNH2 substituent into the o-, m-, or p-position of the
show the Mϩ peaks of the corresponding phosphanylben- aromatic ring system causes a shift to lower field of the
zylamines along with that of HCl.
13C{1H}-NMR signals of the corresponding carbon atoms
in comparison with those of the unsubstituted carbon
atoms in the corresponding isomers and the phenyl rings,
the δC values of which may be taken as an internal refer-
ence for each compound. On going from the carbonic acids
to the respective potassium or sodium salts the 13C{1H}-
NMR spectra do not change very much, as shown for 5
and Na-5. The δC values of the resonances assigned to C1
and C3ϪC6 remain constant within 1 ppm, whereas the
signal of C2 is shifted significantly (by about 2 ppm). This
is in agreement with the results obtained for benzoic acid
NMR Spectra of the Phosphane Ligands 1؊23
The structural assignments given for 1Ϫ23 are based
mainly on 31P{1H}- and 13C{1H}-NMR spectroscopy. H-
1
NMR spectra will only be discussed in certain cases.
Table 1. 31P{1H}-NMR-spectroscopical data of 1Ϫ23; chemical
1
shifts δP relative to 85% H3PO4; coupling constants J(PH) in Hz
in parentheses[a]
1
Ϫ9.6
Ϫ7.9
Ϫ6.9
Ϫ5.2
Ϫ1.5
Ϫ1.4
Ϫ1.5
Ϫ5.4
10
11
12
13
14
15
15a
16
Ϫ15.0
Ϫ4.3
17
Ϫ35.3
2
17a Ϫ35.7
and benzoates[23a]
.
3
Ϫ38.0
Ϫ22.8
Ϫ14.2
Ϫ1.7
18
19
Ϫ23.0
The 13C{1H}-NMR resonances of the carbon atoms
bearing a CN-substituent in 20Ϫ22 are shifted to higher
field by between 10 and 20 ppm in comparison with those
of the corresponding unsubstituted carbon atoms in the Ph-
groups. This shielding effect of the CN group is well estab-
lished for mono-, di-, and trisubstituted benzonitrile deriva-
4
Ϫ48.4
5
(223.0)
6
20
21
22
23
Ϫ12.8[c], Ϫ6.7[d]
Ϫ5.6[c], Ϫ3.6[d]
Ϫ5.7[c], Ϫ2.5[e]
Ϫ9.8
7
Ϫ1.7
Ϫ4.3
8
9[b]
Ϫ20.5, Ϫ21.2 16a Ϫ2.3
[a]
Solvents: DMSO (1, 3, 5؊7, 20Ϫ22), THF (2, 4, 8), D2O/KOD
(9), CDCl3 (10, 15a, 23), CD2Cl2 (11Ϫ14, 16, 19, 20, 21), [D6]ace-
tone (13, 18), CD3OD (15, 17, 16a, 17a). Ϫ [b] Diastereoisomers. Ϫ
tives[23a][24]
.
In comparison with the corresponding δC values in
[c]
[d]
[e]
Solvent DMSO. Ϫ Solvent CD2Cl2. Ϫ Solvent CDCl3.
phthalic acid (CϪCOOH: δ ϭ 131.4)[25], the 13C{1H}-
The 31P-NMR shifts of the triarylphosphane-type ligands NMR resonances of C2 [in 4: 148.8 (32.0), 8: 146.5 (34.4)
(1Ϫ8, 10, 11, 14Ϫ16, 20Ϫ22) are within a narrow range and 9: 147.3 (34), 147.2 (34)] are shifted drastically to lower
(δP ϭ Ϫ1.4 to Ϫ15.0), and the δP values of 9, 12, 13, 17, field on the introduction of the Ph2P or PhP(Ar) groups,
18 are typical for alkyl-diaryl phosphanes[20] (Table 1). In while those of C4 (δ ϭ 128.8, 129.9 or 130.0 vs. 128.6) are
2
both cases the degree of substitution and the nature of the not changed very much. The coupling constants J[PC(2)]
substituents has little influence on the δP values. The reson- in the substituted aromatic ring systems of 4, 8, and 9 are
ances of the o-isomers are shifted, in most cases, to higher significantly greater than those in 1, 2, 5, and 6. This may
field compared with those of the corresponding m- and p- be due to the pronounced steric effect of the two COOH
isomers (c.f. 10/11, 14/15/16, and 20/21/22). The bidentate groups in o- and m-positions which favors a conformation
carboxylated ligand 9, containing two asymmetrically sub- of the PϪC6H3(COOH)2 unit with the phosphorus lone
stituted phosphorus atoms, is formed as a mixture of two pair in close proximity to C2 (Figure 1b). In general
diastereoisomers (meso form and racemate) as indicated by 2J[PC(2)] in related systems is large when the lone pair is
two very close 31P{1H}-NMR signals. The changes in the close to the C atom and small when it is remote[23b][23c]
.
76
Eur. J. Inorg. Chem. 1998, 73Ϫ82

Water Soluble Phosphanes, IX
FULL PAPER
Table 2. 13C{1H}-NMR data of 1Ϫ23[a,b,c]
C1
C2
C3
C4
C5
C6
C7
C8
C9
C10
C11[d]
167.7
166.8
167.0
1
134.1
(19.2)
137.6
(13.2)
142.9
(14.2)
133.5
(13)
139.3
(26.3)
133.5
(19.2)
132.9
(18.7)
148.8
(32)
130.1
(3.0)
131.1
(6.1)
129.3
(6.1)
138.4
(10)
131.7
(3.1)
131.5
(6.1)
129.5
(7.1)
136.3
(7.1)
133.5
(8)
128.5
129.7
131.0
128.8
129.2
130.1
131.4
129.9
130.0
132.0
133.6
137.4
(12.1)
136.0
(11.0)
135.8
(10.1)
139.3
(9)
133.3
(20.2)
133.2
(20.2)
133.5
(20.2)
135.2
(19)
128.5
(7.1)
128.8
(17.0)
128.9
(7.1)
130.2
(6)
129.4
(8.1)
129.1
(7.1)
129.1
(8.1)
129.4
(6.7)
128.9
(6)
128.7
129.1
129.3
130.5
129.5
129.5
129.7
129.6
128.6
2
128.9
(7.1)
137.2
(20.2)
3
4
131.5
(4)
132.8
137.5
(7)
135.5
177.3[e], 178.7[f]
(2)
169.7
5
136.0
(20.4)
137.2
(13.1)
142.1
(14.2)
133.0
(14.3)
133.0[g]
(14)[g]
132.8
(14)[g]
143.0
(26.5)
133.9
(20.2)
133.3
(19.2)
146.5
(34.4)
147.3
(34)
140.4
(12.2)
135.6
(11.1)
135.1
(10.1)
138.7
(8.1)
135.1
(21.4)
133.5
(20.2)
133.9
(20.2)
134.5
(19.7)
132.4
(17)
6
129.3
(7.1)
138.0
(19.2)
166.9
167.1
7
8
128.0
(5.0)
127.3
136.2
(7.4)
135.1
(8)
135.2
(8)
134.0
177.5[e], 176.0[f]
(3.7)
9[h]
139.3
(8)
170.6[e]
(4)
147.2
(34)
139.2
(8)
132.3
(17)
167.9[f]
10[i] 137.1
(13.2)
138.5
(27.1)
134.4
(19.8)
138.2
(27.8)
132.5
(18.3)
147.7
(24.0)
133.0
(22.9)
134.5
(19.8)
147.0
(22.7)
138.6
(24.9)
132.7
(18.9)
149.5
(15.6)
117.8
(33.0)
137.7
(20.5)
133.4
(19.5)
122.8
(32.8)
130.9
(4.4)
130.6
(7.3)
130.4
(5.1)
130.0
(6.6)
129.8
129.3
136.7
129.0
132.1
127.6
128.1
143.9
129.4[s]
130.6
144.3
129.8
128.5
132.1
111.9
133.0
127.8
Ϫ
136.2
(9.5)
133.9
(19.8)
134.3
(19.8)
131.8
(18.3)
132.3
(18.3)
134.3
(19.5)
134.2
(19.4)
134.1
(19.4)
132.1
(18.3)
133.2
(18.3)
132.2
(18.3)
134.4
(17.3)
134.0
(20.5)
133.9
(20.2)
134.0
(20.5)
133.9
128.7
(7.3)
129.4
(6.6)
128.3
(5.9)
128.9
(6.6)
129.0
(7.1)
129.0
(6.7)
129.0
(7.0)
128.7
(6.6)
130.2
(6.6)
128.8
(6.2)
128.7
(9.2)
128.8
(6.6)
129.2
(7.3)
128.8
(7.3)
128.7
129.0
129.5
128.1
128.7
129.2
129.2
129.1
128.6
130.1
128.6
128.8
129.4
129.5
129.4
129.3
177.8
172.5
177.9
175.0
Ϫ
11[j] 136.2
(4)
Ϫ
138.2
(11.0)
139.2
(13.9)
140.7
(13.2)
135.6
(13.4)
137.7
(11.2)
137.8
(11.1)
137.3
(14.7)
140.4
(14.7)
138.5
(12.2)
134.6
(11.0)
134.5
(10.3)
135.9
(11.0)
135.6
(11.0)
134.7
12[k] 139.9
(10.3)
127.9
Ϫ
132.0
Ϫ
13[l] 138.9
(13.2)
14[m] 136.9
(9.6)
128.5
(5.3)
129.2
(5.7)
Ϫ
134.0
15[n] 137.9
(11.2)
143.9
(7.4)
132.5
(16.3)
Ϫ
16[o] 136.0
(10.6)
127.9
(7.1)
17[p] 140.7
(11.7)
127.5[s]
128.2
(5.9)
131.1
(5.9)
Ϫ
131.1
133.3
Ϫ
17a
140.6
(8.8)
130.4
18[q] 141.1
(13.2)
127.6
(6.9)
128.0
(4.0)
19[r] 135.6
(6.2)
127.0
(2.8)
133.3
(12.6)
133.0
(20.5)
140.4
(16.9)
Ϫ
20
21
22
142.7
(19.8)
136.6
(17.6)
145.0
(17.6)
132.1
(10.3)
112.9
(5.9)
133.8
(5.1)
117.6[s]
(3.7)
129.3
118.7[s]
131.7
(6.6)
Ϫ
118.6[s]
23[u] 144.4
144.4
131.6
133.0
115.8[s]
(3.5)
(17.9)[t]
(17.9)[t]
(10.5)[t,v] (20.6)[t,v] (7.2)[t,v]
[b]
[a] Chemical shift δ(C) relative to TMS; coupling constants nJ(PC) in Hz in parentheses. Ϫ Solvents: CD2Cl2 (10, 20, 21, 23), D2O (8),
[c]
CDCl3 (12, 14 Ϫ 16, 18, 22), [D6]acetone (11, 13), CD3OD (17, 17·HCl), C6H6 (19); [D6]DMSO (1Ϫ4, 6, 7, 9). Ϫ For an indication
[d]
[e]
of the carbon atoms see Figure 1a. Ϫ COOH substituent. Ϫ Potassium salt; COOϪ in the o-position. Ϫ [f] COOϪ in the m-position
[g]
[h]
[i]
to phosphorus. Ϫ
Diastereoisomers. Ϫ
ϪCH2ϪCH2ϪCH2: 22.8, 22.2; CH2ϪCH2ϪCH2: 29.5, 29.4 (13); diasteroisomers. Ϫ
[j]
[
k
]
[
l
]
CH2ϪCOOH: 39.7 (23.5). Ϫ CH2ϪCOOH: 40.9. Ϫ CH2ϪCOOH: 39.6 (24.1); PϪMe: 12.4 (13.9). Ϫ CH2ϪCOOH: 41.1; PϪMe:
12.4 (13.9).Ϫ [m] CH2ϪNH2: 45.5 (22.1). Ϫ CH2ϪNH2: 46.7. Ϫ CH2ϪNH2: 46.3. Ϫ CH2ϪNH2: 44.7 (22.7); PϪMe: 12.2 (13.9).
[n]
[o]
[p]
[q]
[r]
[s]
[t]
Ϫ
CH2ϪNH2: 46.3; PϪMe: 13.0 (14.5). Ϫ CH2ϪNH2: 48.2 (15.5). Ϫ CN groups.Ϫ N ϭ nJ(PC) ϩ mJ(PC) ; n ϭ 1Ϫ3; m ϭ
[v] 1 5 2 6 3
3Ϫ6.Ϫ [u] 4J(PP) ϭ 4.78 ± 0.22 Hz. Ϫ C7: J(PC) ϭ 10.26, J(PC) ϭ 0.36 Hz; C8: J(PC) ϭ 20.30, (PC) ϭ 0.11 Hz; C9: J(PC) ϭ
7.30 Hz.
Seperate resonances are observed for the two COOH signed to the terminal CH2 groups of the (CH2)3 bridge (X-
groups in the 2,3-positions in the phthalic acid derivatives. part of an ABX spin system, A and B ϭ 31P, X ϭ 13C)
In the case of 4 and 8 the signal at δ ഠ 177.5 shows doublet could not be completely resolved, two triplets [2J(PC)] be-
fine structure [3J(PC)] and can therefore be assigned to the ing observed for the medial CH2 group.
COOH groups in the o-position with respect to the P atom.
The presence of two phosphorus atoms in 23 means that
The bidentate ligand 9 is obtained as a mixture of two dia- the C-atoms C1(3), C4(6), and C7ϪC9 represent the X-part
stereoisomers (meso form and racemate, see above) and for of ABX spin systems (X ϭ 13C, A and B ϭ 31P; for the
this reason a doubling of the 13C{1H}-NMR resonances of numbering scheme for the carbon atoms see Figure 3a).
some of the aromatic carbon atoms (C1, C2, C6, C7, C8) Higher order 13C{1H}-NMR spectra appearing as doublets
is observed. Although the fine structure of the signals as- of doublets (C1, C3), five line (C9) and six line patterns
Eur. J. Inorg. Chem. 1998, 73Ϫ82
77

M. Hingst, M. Tepper, O. Stelzer
FULL PAPER
Figure 1. (a) Numbering scheme for the carbon atoms in mono- and disubstituted aromatic phosphanes; (b) conformation of the Ph(R)P-
group with respect to the plane of the substituted aromatic ring; (c) 13C-NMR spectrum of 8
Figure 2. (a) Conformation of the CH2ϪX group in 12 and 17; (b) Experimental Section
1H-NMR spectrum (CH2-part) of 17
Experimental details are given in part VIII of this series[1]. Phe-
nylphosphane, phenylmethyl- and diphenylphosphane were pre-
pared according to literature methods[26]. 2-, 3-, and 4-Fluoroben-
zoic acid, 3-fluorophthalic acid, 2- and 4-fluorophenylacetic acid,
2-, 3-, and 4-fluorobenzonitrile, and 2- and 4-fluorobenzylamine
were purchased from The Aldrich Chemical Company and used
without further purification.
Preparation of 1 by Phosphanylation of 2-FϪC6H4ϪCOOK with
Ph2PK: To 20 ml of a 0.5  solution of Ph2PK (10.0 mmol) in
THF was added 1.8 g (10.0 mmol) of 2-FϪC6H4ϪCOOK with
stirring and the reaction mixture was heated at 60 °C for 20 h.
After extraction with 20 ml of conc. KOH solution the aqueous
phase was acidified with conc. HCl until a precipitate formed. The
(C7, C8) are observed (Figure 3b). The analysis of the latter
mixture was then extracted with 40 ml of diethyl ether and the
gave a value of around 4.8 Hz for the long range P-P cou-
extracts were dried over Na2SO4. Evaporation of the solvent in
pling constant [4J(PP)]. The resonances of C2 and C11 (X-
vacuo gave 1 as a colorless solid. Yield: 1.97 g (64%). Ϫ 1:
parts of XA2 spin systems) show first order triplet splitting,
C19H15O2P (306.3): calcd. C 74.50, H 4.94; found C 74.20, H 4.96.
Ϫ MS: (Mϩ: m/z ϭ 306). Ϫ IR: ν(COOH): 1695, 1305 cmϪ1
.
while singlets are obtained for C4(6) and C5.
The hydrogen atoms of the CH2 groups in 12, 17, 17a,
19, and 19·HCl are diastereotopic due to the asymmetric
substitution at the phosphorus atoms (see Figure 2a). The
1H-NMR spectra of these compounds therefore represent
Preparation of 2 and 4Ϫ8: The lithium salts of the fluorobenzoic
acids or 3-fluorophthalic acid were added at ambient temperature
to either a THF solution of Ph2PK or to a suspension of PhPLi2
in THF (obtained by metalation of PhPH2 with nBuLi in n-hexane
in the presence of tetramethylethylenediamine at Ϫ40 °C), respec-
tively (see Table 4). After the reaction mixtures were refluxed for 2
h the solvents were removed under reduced pressure (30 °C, 1
mbar). The remaining residues were dissolved in 100 ml of water
and filtered through a fine porosity fritted funnel. On acidification
of the filtrate the phosphanes precipitated as colorless powders
1
the AB part of an ABX spin system (A and B ϭ H, X ϭ
31P) and appear as an eight-line pattern in the cases of 17
(Figure 2b), 17a, and 19. The coincidence of lines means
that a six-line pattern is observed for 19·HCl and 12.
This work was supported by the Bundesministerium für Bildung,
Wissenschaft, Forschung und Technologie and the Fonds der Che-
mischen Industrie. The Hoechst AG is thanked for financial support which were further purified by recrystallization from methanol/
and generous gifts of chemicals.
78
water mixtures. In the cases of compounds 4 and 8 the filtrates
Eur. J. Inorg. Chem. 1998, 73Ϫ82

Water Soluble Phosphanes, IX
FULL PAPER
Figure 3. (a) Numbering scheme for the carbon atoms in 23; (b) 13C{1H}-NMR spectrum of 23
Table 3. Selected 1H-NMR data of 10Ϫ19[a]; shifts relative to TMS
7: C20H15O4P (350.3): calcd. C 68.57, H 4.32; found C 68.77, H
4.69. Ϫ MS (Mϩ: m/z ϭ 350). Ϫ IR: ν(COOH) ϭ 1690, 1295 cmϪ1
(int.), coupling constants (in parentheses) in Hz
.
8: C22H15O8P·4H2O (510.4): calcd. C 51.77, H 4.54; found C
52.24 H 4.33. Ϫ MS (Mϩ Ϫ 2 H2O: m/z ϭ 402). Ϫ IR: ν(COOH) ϭ
P(Me)
CH2
NH2 COOH
11.69
1715, 1280 cmϪ1
.
10
11
12
4.12
3.63
1.57 (3.8)[b]
1.59 (3.1)[b]
4.10[c] (16.7)[d]
3.94[c] (Ϫ1.3)[e], Ϫ0.2[f]
3.58
10.74
11.79
Table 4. Syntheses of 2, 4Ϫ8, 10Ϫ13
Ar*F
g (mmol)
Phosphide Solvent Temp. Time Yield
13
14
15
16
17
4.05 (1.65)[g]
3.82
1.95[h]
1.61
2.23
1.37
g (mmol)
ml
[°C]
g (%)
3.83
2
4
5
6
7
8
K-3-fluoro-
Ph2PK
2.24 (10)
Ph2PK
THF
30
60
60
60
60
20
60
20 h 1.97
(64)
1.59 (4.2)[b]
1.31 (3.9)[b]
3.89[c] (14.3)[d]
4.07[c] (Ϫ1.73)[e]
(Ϫ1.94)[f]
3.55
benzoate 1.8 (10)
Li-3-fluoro-
THF
30
2.5 h 3.7
(70)
phthalate 2.94 (15) 3.36 (15)
18
19
1.39
Li-2-fluoro-
PhPLi2
3.05 (25)
PhPLi2
THF
100
5 h
6.3
5.19[i] (221.3)[j] 3.91[c] (14.4)[d]
4.02[c] (0.9)[e,f]
benzoate 7.3 (50)
Li-3-fluoro-
(72)
4.3
THF
80
6 d
19·HCl
4.45 (14.1)[d]
benzoate 5.84 (40) 2.44 (20)
(61)
4.27 (0.3)[e] (Ϫ1.9)[f]
Li-4-fluoro-
PhPLi2
THF
12 h 3.6
(82)
benzoate 3.94 (27) 1.52 (12.5) 50
Li-3-fluoro-
PhPLi2
THF
170
12 h 8.9
(70)
[a] Solvents: CDCl3 (12, 14Ϫ16, 18), CD2Cl2 (10, 13, 19), CD3OD
[b]
[c]
(17), [D6]acetone (11). Ϫ
2J(PH). Ϫ
AB part of ABX spin
[g] 4J(PH). Ϫ Broad. Ϫ δ (PH). Ϫ [j] 1J(PH).
phthalate 9.8 (50) 3.05 (25)
system. Ϫ [d] 2J(HH) (AB). Ϫ [e] 4J(PH) (AX). Ϫ [f] 4J(PH) (BX).
10 K-2-fluorophenyl- Ph2PK
DME 85
12 h 1.94
(58)
[h]
[i]
acetate 2.0 (10.4)
2.6 (11.4)
30
Ϫ
11 K-4-fluorophenyl- Ph2PK
DME 85
30
12 h 1.8
(54)
acetate 2.0 (10.4)
2.6 (11.4)
12 K-2-fluorophenyl- Ph(Me)PK DME 85
12 h 1.88
(70)
were extracted with 30 or 50 ml of diethyl ether prior to acidifi-
cation (reaction conditions and yields are given in Table 4).
acetate 2.0 (10.4)
13 K-4-fluorophenyl- Ph(Me)PK DME 85
acetate 2.18 (11.3) 2.0 (12.4) 30
1.8 (11.4)
30
12 h 1.9
(65)
2: C19H15O2P (306.3): calcd. C 74.50, H 4.94; found C 73.81, H
5.19. Ϫ MS (Mϩ: m/z ϭ 306). Ϫ IR: ν(COOH) ϭ 1695, 1300 cmϪ1
.
4: C20H15O4P (350.3): calcd. C 68.57, H 4.32; found C 67.83, H
4.64. Ϫ MS (Mϩ Ϫ H2O: m/z ϭ 332). Ϫ IR: ν(COOH) ϭ 1715,
Preparation of 9: 1.23 g (32 mmol) of potassium was added to a
solution of 3.45 g (31 mmol) of phenylphosphane in 50 ml of THF
and the reaction mixture was stirred for 2 h. The reaction mixture
was refluxed under nitrogen for an additional 30 min in order to
ensure completion of the reaction. Excess potassium was removed
by decanting the solution. 3.00 g (15 mmol) of 1,3-dibromopropane
was added and the yellow color of the solution disappeared. After
1280 cmϪ1
.
5: C20H15O4P (350.3): calcd. C 68.57, H 4.32; found C 66.93, H
4.42. Ϫ MS (Mϩ: m/z ϭ 350). Ϫ IR: ν(COOH) ϭ 1680, 1300 cmϪ1
.
6: C20H15O4P (350.3): calcd. C 68.57, H 4.32; found C 68.57, H
4.48. Ϫ MS (Mϩ: m/z ϭ 350). Ϫ IR: ν(COOH) ϭ 1680, 1300 cmϪ1
.
Eur. J. Inorg. Chem. 1998, 73Ϫ82
79

M. Hingst, M. Tepper, O. Stelzer
FULL PAPER
dilution with 30 ml of THF a further equivalent of 1.23 g (32
18: C14H16NP (229.3): calcd. C 73.35, H 7.03, N 6.11; found C
mmol) of potassium was added and the reaction mixture was again 72.49, H 7.14, N 6.23. Ϫ MS (Mϩ: m/z ϭ 229). Ϫ IR: νas/νs-NH2 ϭ
refluxed for 2 h. The lithium salt of 3-fluorophthalic acid was ad-
ded and the color of the reaction mixture became dark red. After
stirring for 12 h at 60Ϫ70 °C the color disappeared. All volatile
components were then removed under reduced pressure (30 °C, 1
mbar). The residue obtained was dissolved in 200 ml of water and
filtered through a fritted funnel. The filtrate was washed with three
50-ml portions of diethyl ether and then acidified with half conc.
HCl. The white solid that precipitated was separated by filtration
and recystallized from water/methanol. Yield: 4.1 g (41%). Ϫ 9:
C31H26O8P2 ·4H2O (660.55): calcd. C 56.37, H 5.19; found C 55.51,
H 5.33. Ϫ MS (Mϩ Ϫ 2 H2O: m/z ϭ 552. Ϫ IR: ν(COOH) ϭ 1705,
3366, 3304 cmϪ1
.
19: C13H14NP (215.2): calcd. C 72.54, H 6.56, N 6.51; found C
72.38, H 6.67, N 6.29. Ϫ MS (Mϩ: m/z ϭ 215). Ϫ IR: νas/νs-NH2 ϭ
3366, 3292 cmϪ1
.
Table 5. Syntheses of 14Ϫ23 by nucleophilic phosphanylation of
Ar*F in DME/THF
Ar*F(Cl)
g (mmol)
Phosphide
g (mmol)
Solvent Temp. Time Yield
ml
[°C]
g (%)
1280 cmϪ1
.
14 2-F-benzylamine Ph2PK[a]
3.13 (25) 5.6 (25)
15 3-F-benzylamine Ph2PK[a]
1.25 (10) 2.2 (10)
16 4-F-benzylamine Ph2PK[a]
3.59 (28.7) 6.4 (28.7)
DME 85
1 d
1 d
1 d
1 d
1 d
1 d
6.90
(95)
50
Synthesis of 10Ϫ13. Ϫ General Procedure: To a solution of
Ph2PK or Ph(Me)PK in DME [prepared by metalation of Ph2PH
or Ph(Me)PH with equimolar amounts of potassium] was added po-
tassium 2- or 4-fluorophenyl acetate. The suspensions were refluxed
until the yellow color of the potassium phosphides disappeared.
The solvent was removed under reduced pressure (20 °C, 0.01
mbar) and, in each case, the solid obtained was dissolved in 50 ml
of water. Unreacted phosphane was extracted with dichlorometh-
ane. After cooling to about 0 °C, the aqueous phase was acidified
with conc. HCl. The phosphanylphenylacetic acids precipitated and
were isolated by filtration through a fine porosity fritted funnel. A
slurry was obtained by suspending the residue in 50 ml of water
and 1 equivalent of KOH was added. The solution formed was
filtered, cooled to about 0 °C and acidified with conc. HCl. The
precipitate was isolated by filtration and dried in vacuo (20 °C, 0.01
mbar). The amounts of starting materials and yields are given in
Table 4.
DME 85
1.85
(56)[b]
6.55
(70)[b]
1.12
(54)[b]
3.02
(84)
20
DME 85
30
17 2-F-benzylamine Ph(Me)PK[a] DME 85
0.98 (7.8)
18 4-F-benzylamine Ph(Me)PK[a] DME 85
1.96 (15.7) 2.5 (15.7) 10
1.3 (7.8)
10
19 2-F-benzylamine Ph(H)PK[a] DME 85
7.9
(50)
9.13 (73)
20 2-F-benzonitrile Ph2PLi[c]
1.81 (15) 2.9 (15)
21 3-F-benzonitrile Ph2PLi[c]
1.39 (11.5) 2.2 (11.5)
10.8 (73)
40
THF
30
Ϫ78 15 min 2.65
(62)
Ϫ78 2 min 2.1
(65)
THF
30
22 4-Cl-benzonitrile Ph2PK[a]
DME
30
0
10 h 5.45
(67)
3.95 (28.7)
23 2,5-difluoro-
benzonitrile
6.4 (28.7)
Ph2PK[a]
THF
Ϫ78 1 min 7.76
9.13 (40.7) 100
(81)
2.83 (20.3)
[a]
Prepared by reaction of equivalent amounts of Ph2PH or
[b]
10: C20H17O2P (320.3): calcd. C 74.99, H 5.35; found C 74.33,
Ph(Me)PH with potassium (in DME). Ϫ
Isolated as HCl ad-
ducts, for the preparation from the amines see below. Ϫ [c] Prepared
by reaction of equivalent amounts of Ph2PH with nBuLi (1.6 
solution in n-hexane) in stoichiometric ratios in THF.
H 5.56. Ϫ MS (Mϩ: m/z ϭ 320). Ϫ IR: ν(COOH) ϭ 1714 cmϪ1
.
11: C20H17O2P (320.3): calcd. C 74.99, H 5.35; found C 74.33,
H5.49. Ϫ MS (Mϩ: m/z ϭ 320). Ϫ IR: ν(COOH) ϭ 1736 cmϪ1
.
Synthesis of 20Ϫ23 by Phosphanylation of 2- or 3-Fluoro- and 4-
Chlorobenzonitrile with Ph2PM (M ϭ Li, K): Diphenylphosphane
was dissolved in THF and metalated at 0 °C by the addition of the
eqivalent amount of nBuLi (1.6  solution in n-hexane). The red
colored solution of Ph2PLi was cooled to Ϫ78 °C and stoichio-
metric amounts of 2- or 4-fluorobenzonitrile were added at this
temperature. After removal of the solvent in vacuo the oily residue
was washed with water and recrystallized from ethanol. For the
preparation of 22 and 23, 4-chlorobenzonitrile or 2,6-difluoroben-
zonitrile, respectively, were used as starting materials along with
Ph2PK. Ph2PK was prepared by reaction of equivalent amounts of
Ph2PH and potassium. The workup procedure was the same as
that described above. The crude products were recrystallized from
methanol. Starting materials, reaction conditions and yields are
given in Table 5.
12: C15H15O2P (258.3): calcd. C 69.76, H 5.85; found C 68.96,
H 5.98. Ϫ MS (Mϩ: m/e ϭ 258). Ϫ IR ν(COOH) ϭ 1701 cmϪ1
.
13: C15H15O2P (258.3): calcd. C 69.76, H 5.85; found C 69.08,
H 5.89. Ϫ MS (Mϩ: m/z ϭ 258). Ϫ IR ν(COOH): 1712 cmϪ1
.
Preparation of 14Ϫ19 by Phosphanylation of Fluorobenzylamines.
Ϫ General Procedure: In a typical procedure the fluorobenzyl-
amines were added to a solution of Ph2PK or Ph(Me)PK in DME
with stirring. After heating the reaction mixtures at reflux for 24 h
the solvent was evaporated under reduced pressure (20 °C, 0.01
mbar) and the residue obtained was washed with 100 ml of water.
The crude products were dried in vacuo and isolated by distillation
at 220Ϫ240 °C and 10Ϫ3 mbar. Starting materials, reaction con-
ditions and yields are given in Table 5.
14: C19H18NP (291.4): calcd. C 78.33, H 6.23, N 4.81; found C
77.24, H 6.23, N 4.81. Ϫ MS (Mϩ: m/z ϭ 291). Ϫ IR: νas/νs-NH2 ϭ
20: C19H14NP (287.3): calcd. C 79.43, H 4.91, N 4.81; found C
79.05, H 4.89, N 4.88. Ϫ MS (Mϩ: m/z ϭ 287). Ϫ IR: ν(CN) ϭ
3376, 3313 cmϪ1
.
2219 cmϪ1
.
15: C19H18NP (291.4): calcd. C 78.33, H 6.23, N 4.81; found C
78.10, H 6.54, N 4.83. Ϫ MS (Mϩ: m/z ϭ 291). Ϫ IR: νas/νs-NH2 ϭ
21: C19H14NP (287.3): calcd. C 79.43, H 4.91, N 4.81; found C
79.41, H 4.88, N 4.84. Ϫ MS (Mϩ: m/z ϭ 287). Ϫ IR: ν(CN) ϭ
3371, 3298 cmϪ1
.
2225 cmϪ1
.
16: C19H18NP (291.4): calcd. C 78.33, H 6.23, N 4.81; found C
77.33, H 6.46 N 4.51. Ϫ MS (Mϩ: m/z ϭ 291). Ϫ IR: νas/νs-NH2 ϭ
22: C19H14NP (287.3): calcd. C 79.43, H 4.91, N 4.81; found C
79.02, H 4.84, N 4.86. Ϫ MS (Mϩ: m/z ϭ 287). Ϫ IR: ν(CN) ϭ
3371, 3294 cmϪ1
.
2225 cmϪ1
.
17: C14H16NP (229.3): calcd. C 73.35, H 7.03, N 6.11; found C
72.53, H 7.31, N 6.23. Ϫ MS (Mϩ: m/z ϭ 229). Ϫ IR: νas/νs-NH2 ϭ
23: C31H23NP2 (471.5): calcd. C 78.97, H 4.92, P 13.14; found C
79.01, H 5.04, P 13.07. Ϫ MS (Mϩ: m/z ϭ 471).
3356, 3289 cmϪ1
.
80
Eur. J. Inorg. Chem. 1998, 73Ϫ82

Water Soluble Phosphanes, IX
FULL PAPER
[2c]
Chem. Abstr. 1977, 87, 6654j. Ϫ
M. J. H. Russell, B. A.
Reduction of 20 and 21 with LiAlH4: To a suspension of 0.38 g
(10 mmol) or 0.13 g (3.6 mmol) of LiAlH4 in 80 or 40 ml of THF
was added over 15 min a solution of 2.87 g (10 mmol) of 20 or
1.00 g (3.5 mmol) of 21 in 20 or 10 ml of THF. After stirring for
0.5 h at ambient temperature the reaction mixtures were refluxed
for 1 h. The precipitate formed on the addition of 20 or 50 ml of
water, respectively, was separated by filtration and the solvent was
removed in vacuo (20 °C, 0.01 mbar). The remaining crude reaction
products were purified by vacuum distillation (220Ϫ240 °C, 10Ϫ3
mbar). Yields: 2.45 g (84%) of 14 and 0.82 g (80%) of 15.
Murrer, Fr-Pat. 2489308, 5. 3. 1982 (Johnson Matthey); Chem.
[2d]
Abstr. 1982, 97, 55308q. Ϫ
W. Richter, R. Kummer, K.
Schwirten, DE 3126265, 20. 1. 1983 (BASF AG); Chem. Abstr.
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Protonation of 14 with HCl: 0.5 g (1.7 mmol) of diphenylphos-
phanylbenzylamine (14) was dissolved in diethyl ether. An etheral
solution of HCl was added until no further precipitate was formed.
The solid was filtered off using a coarse porosity fritted funnel and
then dried in vacuo (20 °C, 0.1 mbar). Yield: 0.50 g (89%) of 14a.
[3d]
H. Schumann, J. Blum, Synth. Commun. 1992, 22, 1453. Ϫ
R. Luckenbach, K. Lorenz, Z. Naturforsch. 1977, 32b, 1038.
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Symp. Ser. 308, p. 17; F. R. Hartley, Supported Metal Com-
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[5] [5a]
14a: C19H19ClNP (327.8): calcd. C 69.62, H 5.84, N 4.27; found
C 68.56, H 5.89, N 4.22. Ϫ MS (Mϩ Ϫ HCl: m/z ϭ 291).
Synthesis of 1, 3, 20Ϫ22 in the Superbasic Medium. Ϫ General
Procedure: Diphenyl- or phenylphosphane were added to a suspen-
sion of powdered KOH (88%) in DMSO and the mixtures were
stirred for 1 h at ambient temperature. After addition of the appro-
priate amounts of the fluoroaromatic compounds (see Table 6), the
orange to red colored solutions were heated for 70 h at 60Ϫ70 °C
in the cases of 1 and 3. The reactions of the fluorobenzonitriles
with the phosphanes were complete within a couple of minutes. For
the isolation of 1 and 3 the reaction mixtures were first extracted
with 200 ml of diethyl ether. After acidification with conc. HCl
extraction was repeated with three 75-ml portions of diethyl ether.
The organic extracts were washed with 30 ml of water and then
dried over MgSO4. The residue obtained after evaporation of the
solvents in vacuo was recrystallized from methanol. 20Ϫ22 were
precipitated from the reaction mixtures by addition of 30Ϫ40 ml
of water and separated by filtration. Further purification was pos-
sible by recrystallization from methanol. 1, 3, 20Ϫ22 prepared by
this route gave correct analyses. The compounds were identified by
NMR spectroscopy (see above). Starting materials, reaction con-
ditions and yields are given in Table 6.
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Table 6. Syntheses of 1, 3, 20Ϫ22 by nucleophilic phosphanylation
of Ar*F in the superbasic medium DMSO/KOH
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R. Srinivas, G. K. V. Rao, V. Ravinder, Org. Mass Spectrometry
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Ar*F(Cl)
g (mmol)
Phosphane DMSO KOH
g (mmol) ml
Temp. Time Yield
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1
3
2-fluoro-
Ph2PH
40
70
80
40
50
3.83
(60)
20
72 h 3.5
(46)
benzoic acid 4.65 (25)
3.5 (25)
[16]
[17]
K-4-fluoro- Ph2PH
benzoate
4.5 (25)
1.9
(30)
55Ϫ60 20 h 5.1
4.80 (25.8)
(68)
[18]
[19]
T. Malmstroem, H. Weigl, C. Andersson, Organometallics 1995,
14, 2593.
20 2-fluoro-
Ph2PH
3.83
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20
20
20
10
11.9
D. H. Payne, H. Frye, Inorg. Nucl. Chem. Lett. 1972, 8, 73; J.
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benzonitrile 9.3 (50)
6.06 (50)
min (82)
21 3-fluoro-
Ph2PH
0.77
(12)
10
2.4
[20]
[21]
benzonitrile 1.86 (10)
1.2 (10)
Ph2PH
benzonitrile 1.86 (10)
1.4 (10)
min (82)
22 4-chloro-
1.0
(1.5)
10 2.65
min (92)
[21a] T. Bundgaard, H. J. Jakobsen, Acta Chem. Scand. 1972, 26,
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