α-phosphanyl amino acids: Synthesis, structure and reactivity of N-aryl-α-phosphanylglycines

Article abstract of DOI:10.1002/ejoc.200901251

The novel N-aryl-α-phosphanylglycines 1a-d have been easily prepared by one-pot three-component reactions of di-phenylphosphane, primary arylamines and glyoxylic acid hy-drate in diethyl ether. The reactions proceed via intermediate arylammonium (diphenyl

Full text of DOI:10.1002/ejoc.200901251

FULL PAPER
DOI: 10.1002/ejoc.200901251
α-Phosphanyl Amino Acids: Synthesis, Structure and Reactivity of
N-Aryl-α-phosphanylglycines
Joanna Lach,[a] Cun-Yue Guo,[a][‡] Markus K. Kindermann,[a] Peter G. Jones,[b] and
Joachim Heinicke*[a]
Dedicated to Professor Dr. Alfred Schmidpeter on the occasion of his 80th birthday
Keywords: P ligands / Amino acids / Hydrolysis / Solvent effects / Oligomerization
The novel N-aryl-α-phosphanylglycines 1a–d have been
easily prepared by one-pot three-component reactions of di-
phenylphosphane, primary arylamines and glyoxylic acid hy-
drate in diethyl ether. The reactions proceed via intermediate
arylammonium (diphenylphosphanyl)glycolates 2 and stop at
this stage in the case of N-secondary anilines, for example,
the stable N-methylanilinium phosphanylglycolate 3. The
conversion of 2 into 1 is an equilibrium, as demonstrated by
the reversible hydrolysis of 1b to 2b in [D8]THF containing
acids. This and the sensitivity to hydrolysis hint at an acetal-
like character and partial protonation even at the phosphorus
atom. Oxidation of the N-aryl derivatives 1b,c by aqueous
H2O2 proceeds more rapidly than hydrolysis and provides the
first examples of phosphinoylglycines 5. Oxidation by sulfur
is rapid even at room temperature in methanol, giving the
thiophosphinoylglycines 6. The coordination properties of 1
at the phosphanyl group are characterized by the reaction of
1b with [MVI(CO)5(THF)] (MVI = Cr, Mo, W) and the coordi-
varying amounts of water. The solid α-phosphanyl amino ac- nation chemical shifts in the NMR spectra and νCO shifts in
ids are stable, but in THF or DMSO solution they suffer from
slow decarboxylation, which becomes rapid on heating at
about 80 °C, yielding N-secondary phosphanylmethylanil-
ines 4. Solutions of 1 in the polar protic solvent methanol are
stable over long periods, but show rapid proton/deuterium
exchange even of the α-CH proton in deuteriomethanol and
thus increased CH acidity compared with normal α-amino
the IR spectra of the resulting [(1b)MVI(CO)5] complexes 7b–
9b. The structures of the new compounds were elucidated by
crystal structure analysis of 1b and 6b and the solution NMR
spectroscopic data of all the compounds. Screening for the
nickel-catalysed oligomerization of ethylene showed the for-
mation of active catalysts from 1 and Ni(cod)2.
mary phosphanes extended the range of N-phosphanyl-
methyl amino acids to various P,N-heterocyclic types.[3] In-
stead of PH compounds, the formaldehyde adducts thereof
can also be used.[4] Since 1996 several amino acids with a
phosphanyl group on the phenyl ring of phenylglycine and
phenylalanine[5,6] or in the β position (“phosphinoser-
ines”[7,8] and 4-phosphanylprolines[9,10]) have been reported,
as have their oligopeptides and catalytic screenings.[11] An
α-phosphanyl dialkylamino acid ester, iPr2PCH(NEt2)CO-
OMe, has been obtained from chlorodiisopropylphosphane
and the sodium enolate of N,N-diethylglycine methyl es-
ter,[12] but we have been the first to communicate on acyclic
α-phosphanyl amino acids, N-alkyl-phosphanylglycines.[13]
These compounds proved highly sensitive to hydrolysis, ex-
changed the alkylamino group for a hydroxy group prior to
oxidation when treated with aqueous hydrogen peroxide
and well-defined transition-metal complexes have not yet
been found. The incorporation of P-alkyl instead of P-
phenyl groups led to an increase in the sensitivity of N-
alkyl-α-phosphanylglycines. To obtain more stable α-phos-
phanyl amino acids we systematically varied the nitrogen
Introduction
Synthetic amino acids are of interest in various fields of
chemistry, biochemistry and pharmacy.[1] The first repre-
sentatives with a phosphanyl group were obtained by con-
densation of natural amino acids with secondary phos-
phanes and formaldehyde, usually forming bis(phosphanyl-
methyl) amino acids, and studied with respect to their use
as ligands in rhodium-catalysed hydrogenation reactions
and in complexes for radio-diagnostics.[2] The use of pri-
[a] Institut für Biochemie – Anorganische Chemie, Ernst-Moritz-
Arndt-Universität Greifswald,
Felix-Hausdorff-Str. 4, 17487 Greifswald, Germany
Fax: +49-3834-864377
E-mail: heinicke@uni-greifswald.de
[b] Institut für Anorganische und Analytische Chemie, Technische
Universität Braunschweig,
Hagenring 30, 38106 Braunschweig, Germany
[‡] Present address: Beijing National Laboratory for Molecular
Sciences (BNLMS), Laboratory of New Materials, Institute of
Chemistry, Chinese Academy of Sciences,
2 Zhongguancun N. 1st St., Beijing 100190, P. R. China
Supporting information for this article is available on the
WWW under http://dx.doi.org/10.1002/ejoc.200901251.
1176
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186

Synthesis, Structure and Reactivity of N-Aryl-α-phosphanylglycines
substituents of the (diphenylphosphanyl)glycines and report secondary phosphanes and formaldehyde,[2,4,17] only N-
here on the novel N-aryl derivatives 1, their synthesis, struc- monosubstitution takes place in the reaction with glyoxylic
ture and properties, and the first examples of their transi- acid hydrate. This resembles the behaviour of zwitterionic
tion-metal complexes and their use in homogeneous cataly- α-amino acids such as alanine under mild conditions[2] and
sis.
is thus attributed to the presence of the COOH group.
1
Monitoring of the formation of 1b by 31P and H NMR
spectroscopy ([D8]THF) provided evidence for a stepwise
reaction. A precipitate formed a few minutes after mixing
the ethereal solution of p-toluidine and diphenylphosphane
with the solution of glyoxylic acid monohydrate; its NMR
Results and Discussion
Synthesis of N-Aryl-α-(diphenylphosphanyl)glycines
Whereas most of the previously reported C-phosphanyl- spectra displayed considerable amounts of N-tolylammo-
substituted amino acids were obtained by substitution reac- nium (diphenylphosphanyl)glycolate (2b) in addition to the
tions, replacing a halide or tosylate group of protected main product 1b and minor amounts of residual Ph2PH
amino acids by phosphide, we envisaged the synthesis of and an unidentified compound (δ = –5.5 ppm). Glycolate
the title compounds 1 employing a three-component con- 2b was indicated by the sharp PCH doublet at δ = 4.95 ppm
densation reaction. For pentavalent P–H compounds of the [2J(PH) = 2.4 Hz] downfield from the PCH signal of 1b
types HP(O)R2 and H2P(O)R, three-component condensa- (integral ratio ca. 36:64) and by the typical phosphorus res-
tion reactions with amines and aldehydes or ketones are onance of 2b at δ = 6.4 ppm. These two typical signals are
well known as Kabachnik–Fields reactions.[14,15] For tri- almost identical to those observed in the fully characterized
valent PH compounds such condensation reactions have and stable N-methylanilinium phosphanylglycolate 3b
been reported only for formaldehyde.[3a,16–19] Examples of formed in the reaction of diphenylphosphane and N-meth-
analogous reactions of aldehydes and ketones could not be ylaniline with glyoxylic acid hydrate (Scheme 2). The route
found in an extended search although various C-substituted via 2 distinguishes our reaction from the modified Mannich
α-phosphanyl-alkylamines are available by the addition of mechanism, discussed for the reactions of phosphanes and
phosphanes to Schiff bases.[16,17] Only two-component con- NH amines with formaldehyde;[2,3,17] the latter reacts with
densation reactions of ω-phosphanyl-alkylamines or o- primary or secondary amines easily to form imines or im-
phosphanylanilines with aldehydes or ketones are known monium cations, which add the PH component. We assume
to provide P–C–N heterocycles,[20] which are hydrolytically that the alternative mechanism is associated with the
more stable than acyclic PIII–C–N compounds. Usually COOH group, protonating the amine and intramolecularly
heating with azeotropic removal of water is required. In re- a hydroxy group of the adjacent CH(OH)2 moiety. After
lated studies on arsenic heterocycles,[21] the condensation of the cleavage of water the addition of phosphane is favoured
2-(arsinoalkyl)amines with pyruvic acid took place much over the competing additions of water (back reaction) or of
more readily than with aldehydes or ketones and furnished unprotonated amine. For the second step, the replacement
the heterocyclic arsanyl amino acids in a strongly exother- of the second OH by the amino group, a similar course is
mic reaction in high yield without the need of further heat- expected. The lower rate is attributed to the presence of
ing. Therefore, in our present search for acyclic α-phos- only one OH group and steric hindrance by the diphenyl-
phanyl amino acids, we supposed that the activation of the phosphanyl group. The reaction is driven by the slightly
keto function by the electron-withdrawing COOH group higher stability of 1b·H2O compared with 2b, experimen-
might allow a more facile condensation and thus also three- tally shown by the hydrolysis equilibrium in favour of 1b
component reactions with trivalent PH compounds and (see below).
NH amines, as known for formaldehyde. This assumption
proved incorrect for pyruvic acid but successful for the
more reactive glyoxylic acid in the case of sterically unhin-
dered and sufficiently basic primary amines.
The reaction according to Scheme 1 proceeds at room
temperature simply by adding an ethereal solution of glyox-
ylic acid monohydrate to a solution of the aromatic amine
and diphenylphosphane in diethyl ether and stirring the
mixture for some hours. In addition to the phenyl and p-
tolyl derivatives (1a and 1b), functionally substituted deriv-
atives 1c and 1d were also prepared, which demonstrates
that the scope of the reaction is sufficiently wide to allow
electron-withdrawing or -donating functional groups in the
arylamine. Further intramolecular condensation of the
COOH and the o-hydroxy group of 1d, with the formation
of a six-membered lactol ring, was not observed under these
reaction conditions. In contrast to the usually strongly pre-
ferred bis-phosphanylmethylation of primary amines with 2.
Scheme 1. Three-component synthesis of N-aryl-α-(diphenylphos-
phanyl)glycines 1a–d and the hydrolytic equilibrium between 1 and
Eur. J. Org. Chem. 2010, 1176–1186
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1177

J. Lach, C.-Y. Guo, M. K. Kindermann, P. G. Jones, J. Heinicke
FULL PAPER
Scheme 2. Formation of (diphenylphosphanyl)glycolate 3.
The failure of the conversion of 3 to the corresponding
N-disubstituted α-(diphenylphosphanyl)glycine may be due
to steric hindrance or to a lower thermodynamic stability,
for example, associated with solvation effects. Harsher reac-
tion conditions in the three-component condensation with
glyoxylic acid, that is, heating with azeotropic removal of
water, resulted in mixtures. The reason may be the manifold
condensation reactions of glyoxylic acid hydrate at an ele-
vated temperature[22] and the sensitivity of phosphanylgly-
cines to thermal decomposition.
Scheme 3. Reactions of N-aryl(phosphanyl)glycines 1b,c [Ar: p-
CH3C6H4, p-C(O)CH3C6H4].
Reactivity
(preferred in CD3OD). The much lower extent of hydrolysis
Solid N-aryl(diphenylphosphanyl)glycines 1a–d are stable in the N-aryl- compared with the N-alkyl-α-(diphenylphos-
if stored at ambient temperature under an inert atmosphere. phanyl)glycines is attributed to the much lower basicity of
However, like (diphenylphosphanyl)acetic acid,[23] they un- the arylamino groups and hydrolysis by elimination of
dergo decarboxylation on heating. At 95 °C the reaction is amines from the N-protonated form of 1. The detection of
complete within 2 h, in THF at reflux within 4–5 h. Moni- Ph2PH shows that even the very weakly basic diphenylphos-
toring of the process by NMR reveals mainly 4b and minor phanyl group is slowly cleaved by P-protonation. Thus, it
amounts of (Ph2PCH2)2NpTol[24] (Scheme 3). The phos- can be assumed that the reduced hydrolytic stability of pho-
phanylglycines 1a–d are slowly attacked by atmospheric sphanylglycines compared with normal α-amino acids is
oxygen in the crystalline state, but rapidly in solution, re- caused by the P,N-acetal nature of 1 and destabilizing pro-
sulting in phosphane oxides 5, detectable by NMR, along tonation by the adjacent COOH group. Hence, one might
[25]
with small amounts of Ph2P(O)PPh2
and other byprod- expect greater stability for coordination compounds of the
ucts. Sulfur likewise oxidizes phosphanylglycines at room α-phosphanyl amino acids with the electron lone-pair at
temperature to the corresponding phosphane sulfides, dem- phosphorus blocked by less destabilizing electrophiles than
onstrated on the preparative scale by the synthesis of 6b the proton.
and 6c. For synthetic access to phosphinoylglycines 5, the
Attempts to stabilize 1a–d as BH3 adducts by reaction
oxidation of 1 by excess aqueous hydrogen peroxide (30%) with Me2S–BH3 in THF in a molar ratio of 1:1 to 1:3 led
is more suitable than air oxidation and gives pure products. to mixtures of phosphanylboranes with downfield shifted
Examples are the conversion of 1b and 1c to 5b and 5c, and broad phosphorus resonances, but failed to give de-
respectively. This shows that the N-aryl-α-(diphenylphos- fined pure compounds. The wide spectrum of transition-
phanyl)glycines are markedly less sensitive to hydrolysis metal electrophiles should, however, offer the possibility of
than N-alkyl-α-(diphenylphosphanyl)glycines,[13] which stabilizing the ligands in their complexes and, in addition,
form alkylammonium (diphenylphosphinoyl)glycolates might reveal potential applications of the sensitive but eas-
when treated with aqueous H2O2.
ily accessible phosphorus ligands.
To quantify the sensitivity of N-aryl(phosphanyl)glycines
The η1-P coordination properties of N-aryl-α-phosphan-
towards moisture, solutions of 1b in [D8]THF containing ylglycines were studied by reactions of 1b with [M(CO)5-
excess water were studied by NMR spectroscopy. The trace (THF)] in THF (M = Cr, Mo, W). If solid 1b is added to a
phosphorus signal of the hydrolysis product 2b reversibly solution of [M(CO)5(THF)] in THF, the complexes 7b–9b
increased with temperature. Increased concentrations of are formed in a pure state. Generation of the complexes
water led to increased ratios of 2b:1b. These findings indi- directly at the surface of 1b prevented side-reactions of 1b
cate a temperature- and concentration-dependent hydrolytic in solution. If solutions of 1b in [D8]THF are combined
equilibrium of 2b and 1b in THF (at 25 °C [2b]/{[1b]([H2O]– with [W(CO)5(THF)], the formation of 9b can be detected
1
[2b])} = 8ϫ10–4 mmol–1 based on the H integration of p- by 31P NMR along with substantial amounts of [(Ph2PH)-
Me signals) and that 1b·H2O is more stable than 2b. In W(CO)5][28] and a compound tentatively assigned as
CD3OD solution the hydrolysis of 1b is also minor. The [Ph2PA(O)PB(Ph2)W(CO)5] on the basis of characteristic
hydrolytic equilibrium is accompanied even at room tem- 1JPP and 1JPW couplings. The compounds 7b, 8b and 9b are
perature by slow decomposition reactions leading irrevers- the first examples of defined transition-metal complexes of
ibly to the aforementioned decarboxylation product 4b (diphenylphosphanyl)glycines. The coordination by the
(preferred in [D8]THF) and to small amounts of Ph2PH phosphorus markedly changes the solubility properties. In
1178
www.eurjoc.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186

Synthesis, Structure and Reactivity of N-Aryl-α-phosphanylglycines
contrast to 1b and phosphanylglycines in general, the η1-P- THF form catalysts with high activity in the oligomeriza-
coordinated group 6 metal pentacarbonyl complexes 7b–9b tion of ethylene, yielding waxy low-molecular-weight poly-
are all soluble in CDCl3. In the NMR spectra the coordi- mers and smaller amounts of flash-distillable oligomers
nated 31P nuclei display strong downfield coordina- (C4–C12, mainly C6 and C8), both with high selectivity for
tion shifts, decreasing in the order Cr Ͼ Mo Ͼ W [∆δ31- linear chains with vinyl and methyl end groups (Table 1).
(Pcomplex–ligand) = 64.8, 46.6, 27.2 ppm]; the same trend is Other olefins, for example, 1-hexene, are neither converted
shown by the 13C nuclei of the carbonyl groups. The ∆δ(31P) into oligomers nor incorporated into the growing ethylene
values lie in the upper range of those typical of [(diphenyl- oligomer chain. If 1-hexene is used as the solvent then the
alkylphosphane)MVI(CO)5] complexes.[26] The chemical chain growth is slow because of competing interactions of
shifts of the α-C atoms, PCH and i-C(Ph) are little affected, the catalyst with this olefin, but it is not inserted into the
1
likewise the JPC coupling constants of the sp3-hybridized ethylene oligomer chain. Catalysts formed in situ from (di-
1
α-C atom, whereas the JPC value of the sp2-hybridized i-C phenylphosphanyl)acetic acid and Ni(cod)2 or NiCl2 and
is increased from 16–18 to 32–40 Hz. The one-bond 31P– NaBH4 show the same selectivity.[29] Closer investigation of
183W coupling constant in 9b (249 Hz) and the batho- these industrially important catalysts, applied in the Shell
chromic shifts of the carbonyl stretching frequencies in 7b– Higher Olefin Process,[30] showed that organo- or hydrido-
9b (A1 mode: 2064, 2073, 2071 cm–1; E mode: 1940, 1951,
1938 cm–1), both indicative of the donor ability of the phos-
phane ligands in [R3PW(CO)5] complexes,[26,27] display sim-
ilar values to those of conventional [(diphenylalkyphos-
phane)M(CO)5] complexes.
Although the electron lone-pair at the phosphorus of 1b
is blocked by coordination to soft M(CO)5 fragments and
the coordination properties seem to parallel those of stable
[(diphenylalkylphosphane)M(CO)5] complexes, solutions of
7b–9b in [D8]THF decompose slowly if stored for some
days. Even the somewhat more stable tungsten complex 9b
decomposes completely when subjected to column
chromatography on silica gel and elution with variable
amounts of n-hexane/dichloromethane. Detection of
[(Ph2PH)W(CO)5] by characteristic 31P NMR spectroscopy
gives evidence of proton-mediated P–C bond cleavage.
Although so far no complexes other than the above-men-
Figure 1. Pressure–time plots for the oligomerization of ethylene
tioned η1-P–transition metal(0) systems could be isolated
catalysed by (a) 1c/Ni in THF (solid line), (b) 1b/Ni in THF/1-
as defined compounds, there are hints of the formation of
hexene (50:50 vol.-%; dotted line), (c) 1b/Ni in 1-hexene (dashed
nickel complexes. Solutions of 1b or 1c and Ni(cod)2 in line), (d) 1c/Ni in 1-hexene (dash-dot line).
Table 1. Oligomerization of ethylene by catalysts generated in situ from 1b or 1c and Ni(cod)2.
Entry C2H4 [g, mmol];
solvent [mL]
Ligand, Ni [mmol];
pstart [bar], T [°C], t [h]
Conversion [g, %];
TON [mol/mol],
TOF [mol/molh]
PE wax [g];[a]
1H NMR:[b] M [g/mol] Vin/internal Me/C=C, Me/1000
m.p. [°C], ρ [g/cm3]
Olefin
1
10.8, 385;
toluene 10,
THF 10
1b, 0.1, 0.1;
40, 100, 15
10.6, 98;
3780, n.d.
8.0;
108.6, 0.88
780
76:24
1.6, 29
2
3
4
5
12.6, 449;
THF 20
11.2, 399;
toluene 20
13.4, 477;
THF 20
11.6, 413;
THF 10;
1-hexene 10
10.2, 364;
1-hexene 20
10.1, 360;
1-hexene 11
1b, 0.09, 0.09;
40, 100, 15
1c, 0.1, 0.1;
40, 100, 16
1c, 0.1, 0.1;
40, 100, 16
1b, 0.1, 0.1;
40, 100, 16.8
8.2, 65;
2920, n.d.
10.8, 96;
3850, n.d.
13.2, 98;
4700, 13000
11.4, 98;
5.2;
111.0, 0.92
5.4;
700
715
780
510
88:12
78:22
77:23
70:30
1.3, 25
1.6, 32
1.5, 27
1.8, 48
100, 0.91
10.5.[c]
99–101, 0.91
8.7;
91, 0.89
4060, 6200
6
7
1b, 0.1, 0. 1;
40, 100, 16
1c, 0.1, 0.1;
40, 100, 16
7.0, 69;
2500, 300
3.5, 35;
4.8;
127–129, 0.90
3.5;
1600
1086
80:20
72:28
2.4, 21
2.3, 29
1250, 100
101, 0.90
[a] Solvent and lower α-olefins were separated by flash distillation; for purification of the remaining wax, see the Exp. Sect. [b] NMR
spectra were measured after swelling (24 h, 100 °C) in C6D5Br at 100 °C. [c] 13C NMR spectrum measured in the presence of
[Cr(acac)3] (AQ 1.5 s, DE 6.0 s). n.d.: not determined.
Eur. J. Org. Chem. 2010, 1176–1186
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1179

J. Lach, C.-Y. Guo, M. K. Kindermann, P. G. Jones, J. Heinicke
FULL PAPER
nickel(II) (diphenylphosphanyl)acetate complexes are tive of π interactions with the N-tolyl π system. The confor-
formed and that the catalyst is stabilized by the _PO– chelate mation around the P–C(1) axis is essentially staggered with
backbone.[31] Other types of _PO– nickel chelates, for exam- dihedral angles C(31)–P–C(1)–N of 94.60(8) and 63.49(10)°
ple, phosphanylbenzoate, -enolate or -phenolate ligands, and C(21)–P–C(1)–N of –160.59(8) and 175.76(8)°.
display the same principal behaviour and selectivity,[32]
whereas _PN nickel chelate catalysts[33] need MAO or other
organo-aluminium compounds to form ethylene oligomer-
ization catalysts. Therefore it can be assumed that the cata-
lysts generated from 1b or 1c and Ni(cod)2 are also stabi-
lized by a _PO– chelate backbone and that exploration of
the coordination behaviour of the novel α-phosphanyl
amino acid ligands will reveal further feasible coordination
modes (Figure 1).
Crystal Structures
Detailed structural information on the new N-arylglycine
phosphorus compounds has been provided by single-crystal
X-ray diffraction analyses of 1b (Figure 2) and 6b (Fig-
ure 3), both grown from methanol. Compound 1b crys-
tallizes solvent-free, 6b as a methanol monosolvate. In con-
trast to the zwitterionic N-alkyl(diphenylphosphanyl)gly-
cines,[13] the less N-basic arylamino derivatives 1b and 6b
display non-dissociated carboxylic acid groups. In 1b these
pack to form the usual inversion-symmetric dimers with
O(2)···O(1) 2.6243(12) Å, angle 176.1(19)° (see the Support-
ing Information), whereas the amino group is not involved
in hydrogen bonds. The dimers are connected by additional
weak C–H···O interactions: C(16)–H(16)··O(1) (H···O
2.60 Å, angle 131°) and C(22)–H(22)···O(2) (H···O 2.62 Å,
angle 141°]. In 6b the classic hydrogen-bonding is mediated
by methanol molecules [C(O)O(2)–H(02)···O(99)(Me)–
H(03)···O(1)C(OH): O(2)···O(99) 2.5603(14), O(99)···O(1)
2.7453(15) Å, angles 175(2), 163(2)°] and the dimers extend
in a broad ribbon structure parallel to the z axis (Figure 4)
through much longer N–H(01)···O(2) interactions [N···O
3.2560(16) Å, angle 148(2)°]. In 1b and 6b the bond lengths
and angles have normal values. The nitrogen atom is sp2-
hybridized [C(11)–N–C(1) 118.71(10), 119.85(11)°], indica-
Figure 3. Molecular structure of 6b in the crystal (methanol solv-
ate; ellipsoids drawn at the 50% probability level). Selected bond
lengths [Å] and angles [°]: P–C(1) 1.8588(13), P–C(21) 1.8188(14),
P–C(31) 1.8194(14), C(1)–C(2) 1.5331(18), C(1)–N 1.4367(17), N–
C(11) 1.4116(17); C(21)–P–C(31) 105.70(6), C(21)–P–C(1)
110.18(6), C(31)–P–C(1) 102.76(6), N–C(1)–P 105.00(9), C(2)–
C(1)–P 113.61(9), N–C(1)–C(2) 114.38(11).
Figure 4. Packing of 6b in the crystal (for clarity the N-(p-tolyl)
group is represented only by the position of its i-C atom). The
classic hydrogen bonds combine to form broad ribbons parallel to
the z axis.
Structure and Behaviour in Solution
The structures of all the new compounds in solution were
1
elucidated by reliable and complete sets of H, 31P and 13C
NMR spectroscopic data. Different chemical shift ranges of
the PCH proton and 13C nuclei distinguish the phosphanyl-
glycine and phosphanylglycolate derivatives. A particular
feature of the phosphanylglycines is the dynamic behaviour
of the COOH, NH and PCH protons. The COOH signal is
generally very broad and observable usually only by inte-
gration of the downfield region (below 8 ppm; see the Sup-
porting Information). The appearance of the NH and CH
signals depends on the N substituent and the temperature.
Whereas the N-phenyl derivative 1a in [D8]THF displays
separate broad NH and PCH singlets at room temperature
and the less N-basic p-acetophenyl derivative 1c doublets
Figure 2. Molecular structure of 1b in the crystal (ellipsoids drawn
at the 50% probability level). Selected bond lengths [Å] and angles
[°]: P–C(1) 1.8946(12), P–C(21) 1.8325(12), P–C(31) 1.8341(12),
C(1)–C(2) 1.5197(16), C(1)–N 1.4521(15), N–C(11) 1.4109(15);
C(21)–P–C(31) 102.51(5), C(21)–P–C(1) 99.12(5), C(31)–P–C(1)
101.28(5), N–C(1)–P 106.94(8), C(2)–C(1)–P 107.48(8), N–C(1)–
C(2) 113.32(9).
3
with JHH coupling, the more N-basic p-tolyl and o-hy-
1180
www.eurjoc.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186

Synthesis, Structure and Reactivity of N-Aryl-α-phosphanylglycines
droxyphenyl derivatives 1b and 1d show a very broad and signal of 1b is only slightly different for the two solvents
flat NH signal and a broadened PCH peak. Variable-tem- [D8]THF and CD3OD at room temperature (δ = –0.22 and
perature 1H NMR measurements of 1b indicate that the 1.3 ppm) and little affected by the addition of excess glacial
higher basicity at the nitrogen atom causes the collapse of acetic acid (1:5 molar ratio, [D8]THF: δ = –0.09 ppm;
3
2
the JHCNH and JPCH fine-coupling at lower temperature.
CD3OD: δ = 1.3 ppm), pyridine ([D8]THF: δ = –0.27 ppm;
The solution behaviour of 1b was studied in more detail. CD3OD: δ = 0.7 ppm), or tert-butylamine (CD3OD: δ =
3
2
At –50 °C doublets of doublets with JHCNH and JPCH 1.5 ppm). This suggests that the extent of P-protonation in
couplings are observed for PCH, at –20 °C doublets and at the equilibrium remains rather low despite the clear effects
0 °C coalescence to two broad singlets (Figure 5). The NH on the reactivity and stability of the α-phosphanyl amino
signal becomes very broad and flat (visible by integration) acids.
on heating above room temperature, is symmetrically super-
imposed over the PCH signal at 40 °C and found slightly
Conclusions
upfield at 55 °C. The PCH2 doublet of 4b, still very weak
after 2 d at room temperature, increases rapidly on heating
to 40 °C and particularly on heating to 55 °C and indicates
the above-mentioned decarboxylation. The behaviour of 1b
in [D6]DMSO is similar, but the line-broadening is slightly
less, being comparable at 25 °C with that of 1b in THF at
0 °C. A trace amount of an oxidation product is detectable
by 31P NMR (δ = 48 ppm) on heating at 40 and 55 °C, but
no extensive oxidation by the sulfoxide solvent occurs. In
the protic polar solvent CD3OD the picture is different. The
NH and PCH protons do not exhibit separate signals. Only
a broad OH singlet of CD3OH is visible, with a strong up-
field shift with increasing temperature, as is known for
methanol. NH and PCH protons undergo H/D exchange
with the excess solvent. The exchange of the PCH proton
by deuterium was confirmed by 13C NMR spectroscopy.
The α-CH signal of 1b cannot be observed in CD3OD be-
cause of H/D exchange. If a base such as tert-butylamine is
added immediately to a freshly prepared solution of 1b, the
PCH signal is still observed, that is, complete PCH/PCD
exchange is suppressed. The dynamic properties in solution
in the absence of base are attributable to a rapid proton
exchange on the NMR timescale between the acidic COOH
and the Lewis basic amino or phosphanyl group. As shown
by the PCH/PCD exchange in the deuterium donor solvent
CD3OD, even the usually rather weakly acidic α-CH proton
is involved in quite rapid proton (deuterium) transfer reac-
tions. Finally, it should be mentioned that the phosphorus
N-Aryl-α-phosphanylglycines, novel α-phosphanyl amino
acids with reduced basicity at the nitrogen atom, are easily
accessible by one-pot three-component reactions of primary
arylamines, diphenylphosphane and glyoxylic acid hydrate
in diethyl ether at room temperature. The reaction is restric-
ted to N-monosubstituted amines and was found to involve
intermediate arylammonium (diphenylphosphanyl)glycol-
ates, which reversibly condense to the slightly more stable
phosphanylglycines. Compared with conventional α-amino
acids, the α-phosphanylglycines are much more sensitive to
decarboxylation and hydrolysis. N-Aryl substituents are less
sensitive to hydrolysis than N-alkylated phosphanylglycines
and provide sufficient stabilization to allow an easy access
to stable α-phosphinoylglycines by oxidation with aqueous
hydrogen peroxide. [η1-P-(Diphenylphosphanyl)glycineM-
(CO)5] complexes, obtained by reaction of 1 with [M(CO)5-
(THF)] (M = Cr, Mo, W), demonstrate the accessibility of
phosphanylglycine transition-metal complexes and show
that the phosphorus donor properties are comparable to
those of the usual alkyldiphenylphosphanes. Although the
electron lone-pair at phosphorus is blocked, the complexes
remain sensitive to hydrolysis. Nevertheless, highly active
catalysts for oligomerization of ethylene are formed in situ
from THF solutions of the phosphanylglycines and Ni-
(cod)2. The selectivity is the same as with the less easily
accessible but hydrolytically more stable (diphenylphos-
phanyl)acetic acid ligand and hints at catalyst stabilization
by a _PO– nickel chelate backbone. The performance of the
test ligands 1b and 1c in catalytic ethylene oligomerization
suggests that exploring the transition-metal coordination
and ways of stabilizing complexes of phosphanylglycines
may reveal applications of the novel phosphanylglycine li-
gands in coordination chemistry and transition-metal-cata-
lysed reactions.
Experimental Section
General: All manipulations with air-sensitive compounds were con-
ducted under nitrogen using Schlenk techniques. Solvents were
dried by standard methods and freshly distilled before use. NMR
tubes of samples repeatedly measured over several days were closed
by ground glass joints or sealed off to avoid slow oxidation by air
diffusing through the usual plastic caps. Diphenylphosphane was
prepared from triphenylphosphane by phenyl cleavage with sodium
(2 equiv.) in liquid ammonia and neutralization with excess
Figure 5. Variable-temperature proton signals of the NH and PCH
nuclei of 1b in [D8]THF.
Eur. J. Org. Chem. 2010, 1176–1186
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1181

J. Lach, C.-Y. Guo, M. K. Kindermann, P. G. Jones, J. Heinicke
FULL PAPER
NH4Cl.[34] Other chemicals were purchased and used without fur-
ther purification. NMR spectra were recorded with a multinuclear
Bruker ARX300 FT-NMR spectrometer at 300.1 (1H), 75.5 (13C)
and 121.5 (31P) MHz. Chemical shifts (δ) are given in ppm and are
referenced to tetramethylsilane for 1H and 13C NMR and to H3PO4
(85%) for 31P NMR unless indicated otherwise. The relative inten-
sities of the phosphorus signals do not represent quantitative molar
ratios; they are used for rough estimations of the main, side and
trace components or to observe changes in the relative concentra-
tion of a particular component. Coupling constants refer to JHH
(in 1H NMR) or JPC (in 13C NMR) unless stated otherwise. Assign-
ments of the C and H signals of the two P-phenyl groups, usually
different by virtue of the asymmetric α-C atom, are indicated by i,
130.06 (s, p-CHB), 133.53 (d, 2J = 17.8 Hz, 2 o-CHA), 135.31 (d, 2J
1
= 21.6 Hz, 2 o-CHB), 136.24 (d, J = 15.9 Hz, i-CqA), 137.28 (d, 1J
= 17.9 Hz, i-CqB), 146.17 (d, 3J = 7.6 Hz, i-CqЈ), 172.37 (d, 2J =
9.5 Hz, COOH) ppm. 31P{1H} NMR ([D8]THF): δ = 0.22 ppm. IR
(KBr disc): ν = 3368 (m), 3051 (m), 2917 (m), 2611 (mw), 2534
˜
(mw), 1698 (vs), 1614 (m), 1514 (s), 1481 (m), 1432 (m), 1292 (m),
1264 (s), 817 (s), 743 (s), 696 (s) cm–1. C21H20NO2P (349.36): calcd.
C 72.20, H 5.77, N 4.01; found C 72.27, H 5.48, N 3.81.
α-(Diphenylphosphanyl)-N-(4-acetylphenyl)glycine Methanol Solvate
(1c): A solution of glyoxylic acid monohydrate (0.50 g, 5.43 mmol)
in diethyl ether (10 mL) was added to a solution of diphenylphos-
phane (1.01 g, 5.4 mmol) and 4-aminoacetophenone (0.73 g,
5.4 mmol) in diethyl ether (10 mL). Work-up as described for 1a
furnished a white powder (1.1 g, 54%), m.p. 104–106 °C. The sub-
stance is easily soluble in methanol and crystallizes in the form of
o, m and p and by lower case and B. The C and H atoms of the
A
N-aryl groups are denoted by either iЈ, oЈ, mЈ and pЈ or by numbers
(N atom at C1). Elemental analyses were determined with a
CHNS-932 analyser from LECO (standard conditions). Melting
points (uncorrected) were measured in a capillary tube with a
Sanyo Gallenkamp melting-point apparatus.
1
needles when the solution is concentrated. H NMR ([D8]THF): δ
= 2.36 (s, 3 H, CH3), 5.01 (d, J = 9.1 Hz, 1 H, PCH), 6.00 (d, J =
8.1 Hz, 1 H, NH), 6.69 [m(AAЈ), 2 H, oЈ-CH], 7.24–7.38 (m, 6 H,
PhH), 7.45–7.58 (m, 4 H, PhH), 7.73 [m(BBЈ), 2 H, mЈ-CH] ppm.
13C{1H} and DEPT-135 NMR ([D8]THF): δ = 25.79 (s, CH3),
57.67 (d, 1J = 19.1 Hz, PCH), 113.02 (s, 2 oЈ-CH), 128.44 (s, pЈ-
α-(Diphenylphosphanyl)-N-phenylglycine, MeOH Solvate (1a): A
solution of glyoxylic acid monohydrate (0.5 g, 5.43 mmol) in diethyl
ether (10 mL), best prepared in an ultrasound bath, was added to
a solution of diphenylphosphane (1.0 g, 5.37 mmol) and aniline
(0.50 g, 5.37 mmol) in diethyl ether (10 mL). After a few minutes
precipitation of a white solid began. The mixture was stirred over-
night, the solid filtered off, washed with diethyl ether and dried in
vacuo to give a white powder (1.2 g, 67%), m.p. 119–121 °C. The
3
3
Cq), 128.96 (d, J = 7.8 Hz, 2 m-CHA), 129.24 (d, J = 6.5 Hz, 2
m-CHB), 129.67 (s, p-CHA), 130.25 (s, p-CHB), 130.88 (s, 2 mЈ-CH),
133.73 (d, 2J = 19.0 Hz, 2 o-CHA), 135.27 (d, 2J = 21.3 Hz, 2 o-
CHB), 135.89 (d, 1J = 16.3 Hz, i-CqA) 136.72 (d, 1J = 16.7 Hz, i-
CqB), 152.20 (d, 3J = 6.6 Hz, iЈ-Cq), 171.63 (d, 2J = 8.9 Hz, COOH),
194.51 (s, CO) ppm. 31P NMR ([D8]THF): δ = 0.24 ppm. For meth-
anol solvate: C23H24NO4P (409.14): calcd. C 67.47, H 5.91, N 3.42;
found C 67.21, H 6.19, N 3.63.
1
compound was crystallized from methanol. H NMR ([D8]THF):
3
δ = 4.88 (br. s, 1 H, PCH), 5.13 (very br. s, 1 H, NH), 6.59 (tt, J
4
3
4
= 7.2, J = 0.9 Hz, 1 H, pЈ-CH), 6.66 (dt, J = 8.4, J = 0.9 Hz, 2
H, oЈ-CH), 7.04 (ddt, 3J = 8.4, 7.2, 4J = 1–2 Hz, 2 H, mЈ-CH),
7.24–7.35 (m, 6 H, Ph), 7.46–7.57 (m, 4 H, Ph), 3.26 (s,
MeOH) ppm. 13C{1H} and DEPT-135 NMR ([D8]THF): δ = 58.06
(d, 1J = 17.5 Hz, PCH), 114.32 (s, 2 oЈ-CH), 118.42 (s, pЈ-CH),
128.90 (d, 3J = 7.0 Hz, 2 m-CHA), 129.07 (d, 3J = 12.9 Hz, 2 m-
CHB), 129.40 (s, p-CHA), 129.56 (s, 2 mЈ-CH), 130.14 (s, p-CHB),
133.57 (d, J = 18.5 Hz, o-CHA), 135.32 (d, J = 21.2 Hz, o-CHB),
136.13 (d, 1J = 15.9 Hz, i-CqA), 137.15 (d, 1J = 17.2 Hz, i-CqB),
148.43 (d, 3J = 7.8 Hz, iЈ-Cq), 172.34 (d, 2J = 9.3 Hz, COOH),
49.82 (MeOH) ppm. 31P{1H} NMR ([D8]THF): δ = –0.09 ppm.
For the methanol solvate: C21H22NO3P (367.13): calcd. C 68.66, H
6.04, N 3.81; found C 68.62, H 5.98, N 3.62.
α-(Diphenylphosphanyl)-N-(2-hydroxyphenyl)glycine (1d): A solu-
tion of glyoxylic acid monohydrate (0.50 g, 5.43 mmol) in diethyl
ether (20 mL) was added to a solution of diphenylphosphane
(1.0 g, 5.37 mmol) and o-aminophenol (0.59 g, 5.4 mmol) in diethyl
ether (5 mL). Work-up as described for 1a furnished a white pow-
der (1.51 g, 80%), m.p. 110–115 °C. 1H NMR ([D8]THF): δ = 4.87
(s, 1 H, PCH), 6.35–6.64 (m, 4 H, 3Ј-CH to 6Ј-CH), 7.25–7.34 (m,
6 H, PhH), 7.41–7.58 (m, 4 H, PhH) ppm. 13C{1H} and DEPT-135
2
2
1
NMR ([D8]THF): δ = 57.70 (d, J = 19.6 Hz, PCH), 111.98 (s, 6-
CH), 114.23 (s, 3-CH), 118.00 (s, 4-CH), 120.53 (s, 5-CH), 128.83
3
3
(d, J = 7.3 Hz, m-CHA), 128.95 (d, J = 5.7 Hz, m-CHB), 129.34
(s, p-CHA), 129.91 (s, p-CHB), 133.89 (d, 2J = 18.8 Hz, o-CHA),
2
1
135.07 (d, J = 21.2 Hz, o-CHB), 136.32 (d, J = 16.5 Hz, i-CqA),
136.83 (d, 1J = 18.6 Hz, i-CqB), 137.05 (d, 3J = 6.1 Hz, 1-Cq),
145.70 (s, 2-Cq), 172.17 (d, 2J = 8.1 Hz, COOH) ppm. 31P{1H}
NMR ([D8]THF): δ = 0.99 ppm. C20H18NO3P (351.10): calcd. C
68.37, H 5.16, N 3.99; found C 68.59, H 4.81, N 3.70.
α-(Diphenylphosphanyl)-N-(p-tolyl)glycine (1b): A solution of glyox-
ylic acid monohydrate (0.60 g, 6.5 mmol) in diethyl ether (7 mL)
was added to a solution of diphenylphosphane (1.21 g, 6.5 mmol)
and p-toluidine (0.70 g, 6.5 mmol) in diethyl ether (15 mL). Work-
up as described for 1a furnished a white powder (2.2 g, 97%), m.p.
138–140 °C, that is soluble in methanol or THF, but at best spar-
ingly soluble in water. Single crystals (colourless needles and col-
umns) were obtained from a freshly prepared saturated solution in
methanol. Crystal data are compiled in Table 2, selected bond
N-Methylanilinium (Diphenylphosphanyl)glycolate (3): A solution of
glyoxylic acid monohydrate (0.50 g, 5.43 mmol) in diethyl ether
(20 mL) was added to a solution of diphenylphosphane (1.00 g,
5.37 mmol) and N-methylaniline (580 mg, 5.41 mmol) in diethyl
ether (15 mL). Work-up as described for 1a furnished a white pow-
1
lengths and angles are reported in Figure 2. H NMR ([D8]THF):
δ = 2.05 (s, 3 H, CH3), 4.73 (br. s, Ͼ3 H, PCH, NH, OH), 6.46
der (1.60 g, 86%), m.p. 89–93 °C. 1H NMR ([D8]THF): δ = 2.89
3
3
2
[m(AAЈ), J = 8.4 Hz, 2 H, oЈ-CH], 6.76 [m(BBЈ), J ≈ 8.2 Hz, 2 H, (very br., 6 H, CH3, 3 NH/OH), 5.07 (d, JPH = 2.5 Hz, 1 H,
3
3
mЈ-CH], 7.15–7.23 (m, 6 H, o-CH, p-CH), 7.36–7.45 (m, 4 H, m-
CH), 3.15 (s, 0.1 MeOH) ppm. 1H NMR ([D6]DMSO): δ = 2.14 (s,
3 H, CH3), 4.87 (br. s, 1 H, PCH), 5.69 (very br. s, NH), 6.65
PCHO), 6.60 (tt, J = 7.3 Hz, 1 H, pЈ-CH), 6.69 (m, J = 7–8 Hz,
2 H, oЈ-CH), 7.12 (m, 3J = 8.8, 7.3 Hz, 2 H, mЈ-CH), 7.24–7.33
(m, PhH), 7.42–7.61 (m, PhH) ppm. 13C{1H} and DEPT-135 NMR
3
3
1
[m(AAЈ), J = 8.4 Hz, 2 H, oЈ-CH], 6.89 [m(BBЈ), J ≈ 8.3 Hz, 2 H, ([D8]THF): δ = 40.50 (s, CH3), 73.02 (d, JPC = 26.0 Hz, PCHO),
3
mЈ-CH], 7.33–7.43 (m, 6 H, o-CH, p-CH), 7.45–7.55 (m, 4 H, m-
113.18 (s, 2 oЈ-CH), 117.00 (s, pЈ-CH), 128.64 (d, JPC = 6.7 Hz, 2
CH), 12.30 (very br. s, 1 H, COOH) ppm. 13C{1H} NMR ([D8]-
m-CHA), 128.72 (d, JPC = 6.9 Hz, 2 m-CHB), 129.31 (s, p-CHA),
3
THF): δ = 20.42 (s, CH3), 58.31 (d, 1J = 17.6 Hz, PCH), 114.46 129.38 (s, 2 mЈ-CH, p-CHB), 134.65 (d, JPC = 19.9 Hz, 2 o-CHA),
2
(oЈ-CH), 127.26 (pЈ-Cq), 128.83 (d, 3J = 7.4 Hz, m-CHA), 128.99
134.81 (d, JPC = 18.7 Hz, 2 o-CHB), 136.14 (d, JPC = 17.2 Hz, i-
2
1
3
1
(d, J = 5.4 Hz, m-CHB), 129.29 (s, p-CHA), 130.02 (s, 2 mЈ-CH),
CqA), 137.19 (d, JPC = 14.7 Hz, i-CqB), 151.61 (s, i-CqЈ), 174.28
1182
www.eurjoc.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186

Synthesis, Structure and Reactivity of N-Aryl-α-phosphanylglycines
2
(d, JPC = 10.7 Hz, COOH) ppm. 31P{1H} NMR ([D8]THF): δ = α-(Diphenylphosphinoyl)-N-(4-acetylphenyl)glycine (5c): A mixture
6.44 ppm. C21H22NO3P (367.38): calcd. C 68.66, H 6.04, N 3.81;
found C 68.56, H 6.02, N 4.02. (A small amount of Ph2PH was
detected, increasing with the time because of slow protolytic P–C
cleavage in solution.).
of 1c (635 mg, 1.68 mmol) and aqueous H2O2 (15 mL, 30%) was
stirred for 1 d at room temperature. The resulting small white need-
les were separated, washed with methanol (3 mL) and dried in
1
vacuo (609 mg, 92%), m.p. 151–154 °C. H NMR ([D8]THF): δ =
2.36 (s, 3 H, CH3), 5.41 (dd, 2JPH = 11.8, 3J = 10.5 Hz, 1 H, PCH),
Thermal Decarboxylation of 1b and Detection of N-[(Diphenylphos-
phanyl)methyl]-p-toluidine (4b) and its Oxide 4b(O): Neat 1b
(0.759 g, 2.17 mmol) was heated in a Schlenk flask at 95 °C. After
2 h the solid had turned to a pale-yellow melt that formed a viscous
liquid at room temperature. 31P NMR monitoring in [D8]THF
showed the formation of 4b, (Ph2PCH2)2NpTol[24] (δ = –27.0) and
a trace of Ph2PH (δ = –40.6 ppm), relative intensities 82:17:1. Re-
placement of [D8]THF by CD3OD gave similar shifts for 4b and
(Ph2PCH2)2NpTol (δ = –20.2, –26.6 ppm) and no hint of reaction
of either compound with methanol. The mixture was oxidized by
air and worked up by column chromatography to give 0.42 g (60%)
of 4b(O).
3
6.39 (dd, 3J = 10.2, JPH = 3.9 Hz, 1 H, NH), 6.75 [m(AAЈ)
,
,
3J =
3J =
8.8 Hz, 2 H, oЈ-CH], 7.37–7.56 (m, 6 H, PhH), 7.69 [m(BBЈ)
8.8 Hz, 2 H, mЈ-CH], 7.86–8.02 (m, 4 H, PhH) ppm. 13C{1H} and
DEPT-135 NMR ([D8]THF): δ = 25.87 (s, CH3), 58.14 (d, 1J =
3
68.7 Hz, PCH), 113.23 (2 oЈ-CH), 128.50 (pЈ-Cq), 129.55 (d, J =
3
12.7 Hz, 2 m-CHA), 129.30 (d, J = 12.2 Hz, 2 m-CHB), 130.90 (s,
2 mЈ-CH), 131.32 (d, 1J = 99.8 Hz, i-CqA), 131.95 (d, 1J = 102.2 Hz,
2
2
i-CqB), 132.11 (d, J = 9.4 Hz, 2 o-CHA), 132.57 (d, J = 9.4 Hz, 2
o-CHB), 132.87 (d, 4J = 2.3 Hz, p-CHA), 132.94 (d, J = 2.6 Hz, p-
4
3
CHB), 152.44 (d, J = 8.2 Hz, iЈ-Cq), 169.56 (s, COOH), 195.92 (s,
CO) ppm. 31P{1H} NMR ([D8]THF): δ = 29.92 ppm. IR (KBr
disc): ν = 3431 (vs), 1640 (vs), 1586 (vs), 1405 (s), 1282 (m), 1139
˜
(wm), 821 (wm) cm–1. C22H20NO4P (393.37): calcd. C 67.17, H
5.12, N 3.56; found C 66.90, H 5.10, N 3.48.
4b: 1H NMR ([D8]THF): δ = 2.06 (s, 3 H, CH3), 3.67 (d, 2J =
3
4.1 Hz, 2 H, PCH2), 6.45 [m(AAЈ), J = 8.5 Hz, 2 H, oЈ-CH], 6.76
[m(BBЈ), 3J ≈ 8.1 Hz, 2 H, mЈ-CH], 7.13–7.23 (m, 6 H, o-CH, p-CH), α-(Diphenylthiophosphinoyl)-N-(p-tolyl)glycine, Methanol Solvate
7.28–7.37 (m, 4 H, m-CH) ppm. 13C{1H} and DEPT-135 NMR (6b): A mixture of equimolar amounts of 1b (310 mg, 0.89 mmol)
([D8]THF): δ = 20.45 (s, CH3), 45.31 (d, 1J = 9.0 Hz, PCH2N), and sulfur (28.5 mg, 0.89 mmol) in methanol (10 mL) was stirred
113.51 (oЈ-CH), 126.06 (pЈ-Cq), 129.17 (d, 3J = 6.7 Hz, m-CH), for 1 d at room temperature. Then about 50% of the solvent was
2
129.29 (s, p-CH), 129.93 (s, 2 mЈ-CH), 133.57 (d, J = 18.5 Hz, 2
o-CH), 138.69 (d, 1J = 14.7 Hz, i-Cq), 147.46 (d, 3J = 6.1 Hz, i-
CqЈ) ppm. 31P{1H} ([D8]THF): δ = –20.7 ppm.
evaporated in vacuo, yielding small white needles. These were sepa-
rated by filtration, washed with methanol and briefly dried
(308 mg, 84%), m.p. 77–83 °C. The compound is soluble in THF,
water and to a lesser extent in methanol. A single crystal of the
methanol solvate suitable for X-ray diffraction (for crystal data see
Table 2, selected bond lengths and angles are reported in Figure 3)
was taken directly from the methanol mother liquor. 1H NMR inte-
gration of freshly prepared 6b confirms a 1:1 ratio of 6b/methanol.
On storage the substance loses some methanol. 1H NMR ([D8]-
THF): δ = 2.05 (s, 3 H, CH3), ca. 1.5–2.70 and 2.70–3.00 (br. s, 2
1
2
4b(O): H NMR (CD3OD): δ = 2.16 (s, 3 H, CH3), 4.12 (d, J =
3
6.0 Hz, 2 H, PCH2), 6.58 [m(AAЈ), J = 8.5 Hz, 2 H, oЈ-CH], 6.87
[m(BBЈ)
,
3J ≈ 8.1 Hz, 2 H, mЈ-CH], 7.26–7.64 (m, 6 H, m-CH, p-
CH), 7.82 (m, JPH = 11.5, 3J = 8.0–8.4 Hz, 4 H, o-CH) ppm.
13C{1H} and DEPT-135 NMR (CD3OD): δ = 20.48 (s, CH3), 45.43
[d, 1J = 82.1 Hz, P(O)CH2N], 114.55 (oЈ-CH), 128.24 (pЈ-Cq),
3
129.99 (d, J = 11.9 Hz, m-CH), 130.44 (s, 2 mЈ-CH), 131.95 (d, 1J
3
3
3
H, OH), 4.87 [br. dd, J(HCNH) = 11.2, J(PH) = 4.9 Hz, 1 H, NH],
2
4
= 99.1 Hz, i-Cq), 132.35 (d, J = 9.3 Hz, 2 o-CH), 133.66 (d, J =
2.5 Hz, p-CH), 147.11 (d, 3J = 7.8 Hz, i-CqЈ) ppm. 31P{1H}
(CD3OD): δ = 32.2 ppm. HRMS (ESI in MeOH): calcd. for
C20H21NOP [M + H]+ 322.13553; found 322.13574.
2
3
5.35 [dd, J(PH) = 13.4, J(HCNH) = 11.2 Hz, 1 H, PCH], 6.51
3
3
[m(AAЈ), J ≈ 8.4 Hz, 2 H, 2 oЈ-CH], 6.76 [m(BBЈ), J ≈ 8.3 Hz, 2 H,
2 mЈ-CH], 7.23–7.42 (m, 6 H, 4 m-CH, 2 p-CH), 7.81–7.90 [m,
3J(PH) = 12.8 Hz, 2 H, o-CHA], 7.93–8.02 [m, J(PH) = 13.2 Hz, 2
3
H, o-CHB], 11.15 (br. s, OH), 3.15 (s, 3 H, MeOH) ppm. 13C{1H}
and DEPT-135 NMR ([D8]THF): δ = 19.15 (pЈ-CH3), 48.51
α-(Diphenylphosphinoyl)-N-(p-tolyl)glycine, Methanol Solvate (5b):
Glycine 1b (500 mg, 1.43 mmol) was added to excess aqueous H2O2
(10 mL, 30%) and the mixture shaken at room temperature for 1 d.
The solution was concentrated in vacuo, the resulting precipitate
was separated by filtration, washed with methanol (3 mL) and
dried in vacuo to give a white powder (529 mg, 93%), m.p. 162–
163 °C. 1H NMR ([D8]THF): δ = 2.14 (s, 3 H, CH3), 5.10–5.23 (m,
2 H, PCH, NH), 6.61 (d, 3JPH = 8.4 Hz, 2 H, oЈ-CH), 6.85 (d, 3JPH
= 8.3 Hz, 2 H, mЈ-CH), 7.37–7.53 (m, 6 H, PhH), 7.85–8.00 (m, 4
H, PhH), 3.26 (s, 3 H, MeOH) ppm. 13C{1H} and DEPT-135
NMR ([D8]THF): δ = 20.43 (s, CH3), 59.12 (d, 1J = 70.4 Hz, PCH),
114.86 (2 oЈ-CH), 127.92 (pЈ-CH), 128.81 (d, 3J = 12.1 Hz, 2 m-
CHA), 129.04 (d, 3J = 12.0 Hz, 2 m-CHB), 129.98 (2 mЈ-CH),
1
(MeOH), 57.78 (d, J = 56.7 Hz, PCH), 113.75 (2 oЈ-CH), 126.94
(pЈ-Cq), 127.32 (d, 3J = 13.0 Hz, 2 m-CHA), 127.66 (d, 3J = 12.8 Hz,
2 m-CHB), 128.79 (s, 2 mЈ-CH), 130.68 (d, 1J = 78.0 Hz, i-CqA),
130.75 (d, 4J = 2.6 Hz, p-CHA), 130.98 (d, 4J = 2.7 Hz, p-CHB),
131.13 (d, 2J = 9.6 Hz, 2 o-CHA), 132.07 (d, 2J = 10.5 Hz, o-CHB),
132.14 (d, 1J = 83.2 Hz, i-CqB), 144.18 (d, 3J = 11.9 Hz, iЈ-Cq),
2
167.69 (d, J = 5.1 Hz, COOH) ppm. 31P{1H} NMR ([D8]THF): δ
= 46.5 ppm. C21H20NO2PS (381.43): calcd. C 66.13, H 5.29, N
3.67. For the methanol solvate: C22H24NO3PS (413.47): calcd. C
63.91, H 5.85, N 3.39; found C 65.74, H 5.59, N 3.46.
α-(Diphenylthiophosphinoyl)-N-(4-acetylphenyl)glycine (6c): A mix-
ture of equimolar amounts of 1c (630 mg, 1.67 mmol) and sulfur
(53.4 mg, 1.67 mmol) in methanol (10 mL) was stirred for 1 d at
1
2
132.20 (d, J = 99.6 Hz, i-CqA), 132.32 (d, J = 9.3 Hz, 2 o-CHA),
132.48 (d, 4J = 2.7 Hz, p-CHA), 132.56 (br., superimposed, p-CHB),
2
1
132.78 (d, J = 9.3 Hz, 2 o-CHB), 132.72 (d, J = 101.1 Hz, i-CqB), room temperature and filtered. Then about 50% of the solvent was
145.98 (d, 3J
= 11.6 Hz, iЈ-Cq), 169.93 (s, COOH), 49.77 evaporated in vacuo to give small white needles that were sepa-
(MeOH) ppm. 31P{1H} NMR ([D8]THF): δ = 27.49 ppm. IR (KBr
rated, washed with methanol (5 mL) and dried (649 mg, 95%), m.p.
disc): ν = 3432 (vs), 1635 (m), 1606 (m), 1592 (m), 1437 (s), 1249
164–165 °C. 1H NMR ([D8]THF): δ = 2.36 (s, 3 H, CH3), 5.70 [dd,
˜
(m), 1178 (vs), 1164 (vs), 1124 (s), 887 (s), 741 (vs), 695 (vs) cm–1. 2J(PH) = 12.2, J(HCNH) = 10.6 Hz, 1 H, PCH], 5.90 [dd, J(HCNH)
3
3
MS (EI, 70 eV, 315 °C): m/z (%) = 322 (2), 321 (9) [M – CO2]+, 202
= 10.6, J(PH) = 4.3 Hz, 1 H, NH], 6.73 [m(AAЈ), J ≈ 8.8 Hz, 2 H,
3
3
(24) [Ph2PO]+, 120 (100) [TolNHCH2]+, 91 (19), 47 (17). For the oЈ-CH], 7.32–7.52 (m, PhH), 7.69 [m(BBЈ) 3J ≈ 8.8 Hz, 2 H, mЈ-
,
methanol solvate: C22H24NO4P (397.40): calcd. C 66.49, H 6.09, N
3.52; found C 66.47, H 6.06, N 3.59.
CH], 7.92 (m, 4 H, PhH), 3.26 (s, 0.3 H, MeOH) ppm. 13C{1H}
1
and DEPT-135 NMR ([D8]THF): δ = 25.75 (s, CH3), 58.11 (d, J
Eur. J. Org. Chem. 2010, 1176–1186
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1183

J. Lach, C.-Y. Guo, M. K. Kindermann, P. G. Jones, J. Heinicke
= 54.4 Hz, PCH), 113.33 (2 oЈ-CH), 128.66 (d, J = 12.9 Hz, 2 m- presence of impurities (δ = 6.7 ppm and smaller signals) in addition
FULL PAPER
3
3
CHA), 128.97 (pЈ-Cq), 129.00 (d, J = 12.0 Hz, 2 m-CHB), 130.70
(s, 2 mЈ-CH), 131.67 (partially superimposed d, 1J ≈ 80 Hz, i-CqA),
132.25 (d, 4J = 3.9 Hz, p-CHA), 132.39 (d, 4J = 3.8 Hz, p-CHB),
to the main product (δ = 46.1 ppm)].
η1-P-[α-(Diphenylphosphanyl)-N-(p-tolyl)glycine](pentacarbonyl)-
tungsten(0) (9b): [W(CO)6] (380 mg, 1.08 mmol) was dissolved in
THF (80 mL) and irradiated with a UV immersion lamp until the
calculated amount of CO had been liberated (3.5 h). Solid 1b
(190 mg, 0.54 mmol) was added to the solution of [W(CO)5(THF)].
After stirring for 3 h, the solvent was partially evaporated in vacuo
(residual volume ca. 5 mL). CH2Cl2 (15 mL) was added, the insolu-
ble residue was filtered off and the solution was stored for 3 d at
–24 °C. Small, pale-yellow crystals formed that were separated
from the cold mother liquor, washed with CH2Cl2 (5 mL) and dried
in vacuo (227 mg, 62%). 1H NMR (CDCl3): δ = 2.24 (s, 3 H, CH3),
5.02 [d, 2J(PH) = 9.4 Hz, 1 H, PCH], 6.61 [m(AAЈ), 3J = 8.4 Hz, 2 H,
2
132.40 (d, J = 10.0 Hz, 2 o-CHA), 132.75 (partially superimposed
d, 1J ≈ 80 Hz, i-CqA), 133.30 (d, 2J = 10.6 Hz, 2 o-CHB), 151.58 (d,
3J = 8.1 Hz, iЈ-Cq), 168.29 (d, 2J = 4.0 Hz, COOH), 194.68 (s, CO),
49.77 (MeOH) ppm. 31P{1H} NMR ([D8]THF): δ = 47.3 ppm.
C22H20NO3PS (409.44): calcd. C 64.54, H 4.92, N 3.42; found C
64.44, H 4.77, N 3.33.
η1-P-[α-(Diphenylphosphanyl)-N-(p-tolyl)glycine](pentacarbonyl)-
chromium(0) (7b): [Cr(CO)6] (375 mg, 1.70 mmol) was dissolved in
THF (85 mL) and irradiated with a UV immersion lamp until the
calculated amount of CO had been liberated (3 h). Solid 1b
(650 mg, 1.86 mmol) was then added to the resulting yellow solu-
tion of [Cr(CO)5(THF)]. After stirring for 30 min most of the sol-
vent was evaporated in vacuo to leave a residual volume of around
5 mL. CH2Cl2 (25 mL) was added, insoluble material filtered off
and the solution stored overnight at –20 °C. The small, pale-yellow
crystals that formed were separated from the cold solution and
dried in vacuo (775 mg, 75%). The substance was contaminated by
a small amount of 1b [δ(31P) = 2.8 ppm] and [Cr(CO)6] [δ(13C) =
211.5 ppm]. 1H NMR (CDCl3): δ = 2.24 (s, 3 H, CH3), 5.07 (br., 1
H, PCH), 6.60 (br., 2 H, oЈ-CH), 6.99 (br., 2 H, mЈ-CH), 7.20–7.80
(m, 10 H, 2 PhH), 8.5–9.5 (br. s, 1 H, OH) ppm; NH superimposed.
13C{1H} and DEPT-135 NMR (CDCl3): δ = 20.45 (pЈ-CH3), 58.73
(d, 1J = 15.8 Hz, PCH), 114.57 (s, 2 oЈ-CH), 128.56 (d, 3J ≈ 8.7 Hz,
2 m-CHA), 128.67 (d, 3J = 7.8 Hz, 2 m-CHB), 129.23 (s, pЈ-Cq),
129.92 (s, 2 mЈ-CH), 130.63 (s, p-CHA), 130.78 (s, p-CHB), 132.52
(d, 2J = 10.2 Hz, 2 o-CHA), 132.78 (d, 2J = 10.8 Hz, 2 o-CHB),
132.68 (d, 1J ≈ 34 Hz, i-CqA), 133.47 (d, 1J = 32.4 Hz, i-CqB), 143.66
3
oЈ-CH], 7.00 [m(BBЈ), J ≈ 8.2 Hz, 2 H, mЈ-CH], 7.36–7.51 (m, 6 H,
PhH), 7.54–7.68 (m, 4 H, PhH) ppm. 13C{1H} NMR (CDCl3): δ =
1
20.43 (s, CH3), 59.36 (d, J = 20.2 Hz, PCH), 114.61 (s, 2 oЈ-CH),
128.56 (d, 3J = 9.6 Hz, 2 m-CHA), 128.63 (d, 3J = 10.1 Hz, 2 m-
4
CHB), 129.37 (s, pЈ-Cq), 129.94 (s, mЈ-CH), 130.69 (d, J = 1.6 Hz,
2
p-CHA), 130.98 (br. s, p-CHB), 132.41 (d, J = 11.0 Hz, 2 o-CHA),
1
132.47 (d, J = 39.5 Hz, i-CqA), 133.23 (d, 2J = 11.8 Hz, 2 o-CHB),
133.88 (d, 1J = 38.3 Hz, i-CqB), 143.38 (d, 3J = 9.2 Hz, iЈ-Cq),
2
2
1
171.36 (d, J = 7.0 Hz, COOH), 196.47 (d, satellite, J = 7.4, JWC
2
= 126.0 Hz, 4 cis-CO), 198.75 (d, J = 24.0 Hz, 1 trans-CO) ppm.
31P{1H} NMR (CDCl3): δ = 27.4 (1JPW = 249.4 Hz) ppm. IR (KBr
disc): ν = 3437 (s, br.), 2071 (wm), 1973, 1938 (vs), 1634 (m), 1437
˜
(w), 695 (m), 580 (ms) cm–1. C26H20NO7PW (673.25): calcd. C
46.38, H 2.99, N 2.08; found C 46.44, H 2.91, N 2.02.
Oligo/Polymerization of Ethylene: The various phosphanylglycines
1 (see Table 1) and Ni(cod)2 (each ca. 100 µmol) were dissolved in
THF or toluene (10 mL), cooled to 0 °C (10 min) and mixed. The
resulting yellow-brown solution was stirred at room temperature
for 5 min and transferred through a Teflon® tube to the argon-
filled autoclave. After weighing, the autoclave was pressurized with
ethylene (30–50 bar), the amount of ethylene was determined and
the autoclave was placed in the silicon bath and heated overnight
(15 h) at 100Ϯ5 °C. After cooling to room temperature uncon-
verted ethylene was allowed to escape through a cooling trap
(–40 °C; only trace amounts of butenes were observed). The vola-
tiles were flash-distilled at 80 °C/4.0 mbar from the solvent product
mixture. The residual waxy oligomer or polymer was treated for
1 d with methanol/hydrochloric acid (1:1), thoroughly washed with
methanol and finally dried in vacuo. The density was determined
by the sinking method using polymer tablets (IR press, 10 kbar) in
water/ethanol. The results are compiled in Table 1. The microstruc-
ture and molecular weights of the polyethylene waxes were deter-
mined by 1H NMR at 100 °C in C6D5Br after swelling for 1 d under
argon at 100 °C (acquisition time 4.9–5.4 s, delay 1.0 s). The strong
preference for linear chains with vinyl and methyl end groups was
also confirmed in two control experiments by 13C NMR measure-
ments {acquisition time 0.6–0.9 s, delay 0.1–0.4 s, presence of 3–
5 mg [Cr(acac)3]}. The reference was the p-CH of the solvent: δ(1H)
= 7.23 ppm, δ(13C) = 126.70 ppm.
3
2
(d, J = 8.2 Hz, iЈ-Cq), 171.69 (d, J = 6.2 Hz, COOH), 216.21 (d,
2J = 12.8 Hz, 4 cis-CO), 221.32 (d, 2J = 5.2 Hz, trans-CO) ppm.
31P{1H} NMR (CDCl ): δ = 65.04 ppm. IR (KBr disc): ν = 3419
˜
3
(m, br.), 2064 (wm), 1985 (w), 1940 (vst), 1698 (s), 1615 (m), 1516
(s), 696 (m) cm–1. C26H20CrNO7P (541.41): calcd. C 57.68, H 3.74,
N 2.59; found C 58.12, H 3.58, N 2.45.
η1-P-[α-(Diphenylphosphanyl)-N-(p-tolyl)glycine](pentacarbonyl)mo-
lybdenum(0) (8b): [Mo(CO)6] (283 mg, 1.07 mmol) was dissolved in
THF (85 mL) and irradiated with a UV immersion lamp until the
calculated amount of CO had been liberated (2.5 h, repeated re-
placement of CO by N2). Solid 1b (400 mg, 1.14 mmol) was added
to the resulting yellow solution of [Mo(CO)5(THF)]. After stirring
for 30 min the solvent was evaporated in vacuo. The residue was
taken up in THF (2 mL) and CH2Cl2 (10 mL) was added. After
4 h at –20 °C small yellow crystals had formed that were separated,
washed with CH2Cl2 and dried in a vacuum (509 mg, 76%). 1H
NMR (CDCl3): δ = 2.26 (s, 3 H, CH3), 4.01 (br. s, 1 H, NH), 4.95
3
3
(br. s, 1 H, PCH), 6.61 (d, J = 7.8 Hz, 2 H, oЈ-CH), 7.04 (d, J =
7.7 Hz, 2 H, mЈ-CH), 7.37–7.50 (m, 6 H, PhH), 7.55–7.65 (m, 4 H,
PhH) ppm. 13C{1H} NMR (CDCl3): δ = 20.45 (s, CH3), 58.88 (d,
1J = 14.4 Hz, PCH), 114.57 (s, 2 oЈ-CH), 128.70 (d, J = 9.3 Hz, 2
3
m-CHA), 128.73 (d, 3J = 9.3 Hz, 2 m-CHB), 129.68 (s, pЈ-Cq),
130.03 (s, 2 mЈ-CH), 130.59 (s, p-CHA), 131.00 (s, p-CHB), 132.18
(d, 2J = 11.8 Hz, 2 o-CHA), 132.32 (d, 1J = 33.0 Hz, i-CqA), 133.11
Crystal Structure Analyses: X-ray diffraction data for 1b and 6b
2
1
(d, J = 12.2 Hz, 2 o-CHB), 134.00 (d, J = 33.0 Hz, i-CqB), 143.26 were recorded with an Oxford Diffraction Nova A diffractometer
(d, 3J = 8.8 Hz, iЈ-Cq), 172.23 (d, 2J = 6.5 Hz, COOH), 204.02
using mirror-focussed Cu-Kα radiation. The structures were refined
by full-matrix least-squares methods on F2 for all unique reflections
(SHELXL-97).[35] The NH and OH hydrogen atoms were refined
(d, J = 9.1 Hz, 4 cis-CO) ppm; trans-CO in noise. 31P{1H} NMR
2
(CDCl ): δ = 46.8 ppm. IR (KBr disc): ν = 3435 (s, br.), 2073 (wm),
˜
3
1977, 1951 (vs), 1636 (m), 1436 (w), 590 (s) cm–1. C26H20MoNO7P freely; other hydrogen atoms were calculated by assuming idealized
(585.35): calcd. C 53.35, H 3.44, N 2.39; found C 53.60, H 3.24, N
2.24. [If a solution of 1b in THF was added to the solution of
[Mo(CO)5(THF)], 31P NMR reaction monitoring indicated the
geometries and refined by using riding models or rigid methyl
groups. Crystallographic data are given in Table 2 and selected
bond lengths and angles are presented in Figures 2 and 3. CCDC-
1184
www.eurjoc.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186

Synthesis, Structure and Reactivity of N-Aryl-α-phosphanylglycines
c) N. J. Wardle, S. W. A. Bligh, H. R. Hudson, Curr. Org.
Chem. 2007, 11, 1635–1651; d) P. M. T. Ferreira, L. S. Mon-
teiro, Targets in Heterocycl. Systems 2006, 10, 152–174; e) I.
Rilatt, L. Caggiano, R. F. W. Jackson, Synlett 2005, 18, 2701–
2719.
743854 (for 1b) and -743855 (for 6b) contain the supplementary
crystallographic data for this paper. These data can be obtained
free of charge from The Cambridge Crystallographic Data Centre
via www.ccdc.cam.ac.uk/data_request/cif.
[2]
a) K. Kellner, A. Tzschach, Z. Nagy-Magos, L. Markó, J. Or-
ganomet. Chem. 1980, 193, 307–314; b) K. Kellner, A.
Tzschach, Z. Nagy-Magos, L. Markó, J. Organomet. Chem.
1984, 268, 175–183; c) J. Zhang, J. J. Vittal, W. Henderson, J. R.
Wheaton, I. H. Hall, T. S. Andy Hor, Y. K. Yan, J. Organomet.
Chem. 2002, 650, 123–132.
a) B. A. Arbuzov, G. N. Nikonov, Adv. Heterocycl. Chem. 1994,
61, 59–140; b) A. A. Karasik, I. O. Georgiev, O. G. Sinyashin,
E. Hey-Hawkins, Polyhedron 2000, 19, 1455–1459; c) A. A. Ka-
rasik, I. O. Georgiev, E. I. Musina, O. G. Sinyashin, J. Heinicke,
Polyhedron 2001, 20, 3321–3331.
a) G. Märkl, G. Yu Jin, Tetrahedron Lett. 1981, 22, 223–226;
b) D. E. Berning, K. V. Katti, C. L. Barnes, W. A. Volkert, J.
Am. Chem. Soc. 1999, 121, 1658–1664.
S. R. Gilbertson, G. W. Starkey, J. Org. Chem. 1996, 61, 2922–
2923.
Table 2. Crystal data and structure refinement for 1b and
6b·MeOH.
Compound
1b
6b·MeOH
Empirical formula
Formula weight
Temperature [K]
Wavelength [Å]
Crystal system
Space group
a [Å]
b [Å]
c [Å]
α [°]
C21H20NO2P
349.35
103(2)
C22H24NO3PS
413.45
100(2)
[3]
[4]
1.54184
1.54184
monoclinic
P21/c
C2/c
5.6520(2)
11.7858(4)
26.6778(11)
90
36.9730(18)
10.3299(5)
11.1603(5)
90
[5]
[6]
β [°]
γ [°]
92.757(3)
90
1775.04(11)
4
98.588(5)
90
4214.6(3)
8
Volume [Å3]
Z
a) M. Tepper, O. Stelzer, T. Häusler, W. S. Sheldrick, Tetrahe-
dron Lett. 1997, 38, 2257–2258; b) D. J. Brauer, S. Schenk, S.
Roßenbach, M. Tepper, O. Stelzer, T. Häusler, W. S. Sheldrick,
J. Organomet. Chem. 2000, 598, 116–126.
Density (calcd.)
[Mgm–3]
1.307
1.303
Absorption coefficient
[mm–1]
[7]
[8]
a) C. Meyer, H. Grützmacher, H. Pritzkow, Angew. Chem. Int.
Ed. Engl. 1997, 36, 2471–2473; b) H. Grützmacher, C. Meyer,
S. Boulmaaz, H. Schönberg, S. Deblon, J. Liedtke, S. Loss, M.
Wörle, Phosphorus Sulfur Silicon Relat. Elem. 1999, 114, 465–
468.
a) S. J. Greenfield, S. R. Gilbertson, Synthesis 2001, 2337–2340;
b) D. J. Brauer, K. W. Kottsieper, S. Schenk, O. Stelzer, Z.
Anorg. Allg. Chem. 2001, 627, 1151–1156.
S. R. Gilbertson, R. V. Pawlick, Angew. Chem. Int. Ed. Engl.
1996, 35, 902–904.
M. Porte, W. A. van der Donk, K. Burgess, J. Org. Chem. 1998,
63, 5262–5264.
S. R. Gilbertson, S. E. Collibee, A. Agarkov, J. Am. Chem. Soc.
2000, 122, 6522–6523.
Z. S. Novikova, S. N. Zdorova, I. F. Lutsenko, Zh. Obshch.
Khim. 1976, 46, 433–434.
J. Heinicke, N. Peulecke, P. G. Jones, Chem. Commun. 2005,
262–264.
a) M. I. Kabachnik, T. Y. Medved, Dokl. Akad. Nauk SSSR
1952, 83, 689–692; b) E. K. Fields, J. Am. Chem. Soc. 1952, 74,
1528–1531.
For a review, see: R. A. Cherkasov, V. I. Galkin, Russ. Chem.
Rev. 1998, 67, 857–882.
For a review, see: W. Wolfsberger, Chem. Zeitg. 1985, 109, 317–
322.
For a review, see: K. Kellner, A. Tzschach, Z. Chem. 1984, 24,
365–375.
H. Coates, P. T. A. Hoyes, Brit. Pat. 842593, 1960 [Chem. Abstr.
1961, 55, 4363c].
H. K. A. Petrov, V. A. Parshina, B. A. Orlov, G. M. Cypina,
Zh. Obshch. Khim. 1962, 32, 4017–4022.
1.479
736
2.264
1744
F(000)
Crystal size [mm3]
θ range for data
collection [°]
Index ranges
0.30ϫ0.03ϫ0.01 0.15ϫ0.15ϫ0.02
4.10–75.59
–6ՅhՅ6,
–14ՅkՅ14,
–33ՅlՅ31
19459
4.45–75.9
–46ՅhՅ46,
–12ՅkՅ12,
–14ՅlՅ12
44913
4343 [R(int) =
0.0563]
[9]
Reflections collected
Independent reflections 3563 [R(int) =
[10]
[11]
[12]
[13]
[14]
0.0290]
98.7% to θ =
67.5°
Completeness
99.8% to θ = 72.5°
Absorption correction
Max. and min. trans-
mission
semi-empirical from equivalents
1.00000 and
0.84548
1.00000 and
0.76948
Refinement method
Data/restraints/param-
eters
full-matrix least-squares on F2
3563/0/235
1.060
R1 = 0.0304,
wR2 = 0.0823
R1 = 0.0341,
wR2 = 0.0851
4343/0/267
1.058
R1 = 0.0321, wR2
= 0.0857
R1 = 0.0376, wR2
= 0.0883
Goodness-of-fit on F2
Final R indices [I Ͼ
2σ(I)]
[15]
[16]
[17]
[18]
[19]
[20]
R indices (all data)
Largest diff. peak and
hole [eÅ–3]
0.269 and –0.261
0.306 and –0.331
Supporting Information (see also the footnote on the first page of
this article): Additional experiments and NMR spectroscopic data,
1H and 31P NMR spectra of selected products and 13C NMR spec-
tra of all products, packing figure of 1b in the crystal.
a) For a review, see: K. Issleib, Phosphorus Sulfur Relat. Elem.
1976, 2, 219–235; b) K. Issleib, H. Oehme, R. Kümmel, E. Le-
issring, Chem. Ber. 1968, 101, 3619–3622; c) K. Issleib, H.
Oehme, E. Leissring, Chem. Ber. 1968, 101, 4032–4035; d) K.
Issleib, H.-U. Brünner, H. Oehme, Organomet. Chem. Synth.
1970/71, 1, 161–168.
A. Tzschach, J. Heinicke, Arsenheterocyclen, Deutscher Verlag
für Grundstoffindustrie, Leipzig, 1978, p. 158.
F. Chastrette, C. Bracoud, M. Chastrette, G. Mattioda, Y.
Acknowledgments
C.-Y. G. acknowledges funding by a Deutscher Akademischer Aus-
tauschdienst (DAAD)–K. C. Wong fellowship. We thank G. Thede
and M. Steinich for numerous NMR measurements.
[21]
[22]
[23]
Christidis, Bull. Soc. Chim. Fr. 1985, 2, 66–74.
J. A. van Doorn, N. Meijboom, J. Chem. Soc. Perkin Trans. 2
1989, 1309–1313.
[1] For recent reviews, see, for example: a) D. Haldar, Curr. Org.
Synth. 2008, 5, 61–80; b) R. Mazurkiewicz, A. Kuznik, M.
Grymel, A. Pazdzierniok-Holewa, ARKIVOC 2007, 193–216;
Eur. J. Org. Chem. 2010, 1176–1186
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
1185

J. Lach, C.-Y. Guo, M. K. Kindermann, P. G. Jones, J. Heinicke
FULL PAPER
[24]
[31] a) M. Peuckert, W. Keim, Organometallics 1983, 2, 594–597; b)
M. Peuckert, W. Keim, S. Storp, R. S. Weber, J. Mol. Catal.
1983, 20, 115–127; c) W. Keim, Angew. Chem. Int. Ed. Engl.
1990, 29, 235–244; d) W. Keim, R. P. Schulz, J. Mol. Catal.
1994, 92, 21–33.
[32] a) A. Kermagoret, P. Braunstein, Dalton Trans. 2008, 822–831;
b) P. Kuhn, D. Sémeril, D. Matt, M. J. Chetcuti, P. Lutz, Dalton
Trans. 2007, 515–528; c) J. Heinicke, N. Peulecke, M. Köhler,
M. He, W. Keim, J. Organomet. Chem. 2005, 690, 2449–2457.
[33] a) Z. Weng, S. Teo, Z.-P. Liu, T. S. A. Hor, Organometallics
2007, 26, 2950–2952; b) F. Speiser, P. Braunstein, L. Saussine,
Acc. Chem. Res. 2005, 38, 784–793; c) X. Tang, D. Zhang, S.
Jie, W.-H. Sun, J. Chen, J. Organomet. Chem. 2005, 690, 3918–
3928; d) W. Keim, S. Killat, C. F. Nobile, G. P. Suranna, U.
Englert, R. Wang, S. Mecking, D. L. Schroder, J. Organomet.
Chem. 2002, 662, 150–171; e) Z. Guan, W. J. Marshall, Organo-
metallics 2002, 21, 3580–3586.
a) D. L. Davies, J. Neild, L. J. S. Prouse, D. R. Russell, Polyhe-
dron 1993, 12, 2121–2124; b) A. L. Balch, M. M. Olmstead,
S. P. Rowley, Inorg. Chim. Acta 1990, 168, 255–264.
[25]
[26]
E. Fluck, H. Binder, Inorg. Nucl. Chem. Lett. 1967, 3, 307–313.
a) S. O. Grim, D. A. Wheatland, W. McFarlane, J. Am. Chem.
Soc. 1967, 89, 5573–5577; b) G. M. Bodner, M. P. May, L. E.
McKinney, Inorg. Chem. 1980, 19, 1951–1958; c) G. M.
Bancroft, L. Dignard-Bailey, R. J. Puddephatt, Inorg. Chem.
1986, 25, 3675–3680.
[27] O. Kühl, Coord. Chem. Rev. 2005, 249, 693–704.
[28] a) M. Scheer, S. Gremler, Z. Anorg. Allg. Chem. 1993, 619, 471–
475; b) J. G. Smith, D. T. Thompson, J. Chem. Soc. A 1967,
1694–1697.
[29] a) W. Keim, R. S. Bauer, H. Chung, P. W. Glockner, W. Keim,
H. van Zwet, US Pat. 3635937, 1972; b) R. S. Bauer, H. Chung,
P. W. Glockner, W. Keim, US Pat. 3644563, 1972; c) R. S.
Bauer, P. W. Glockner, W. Keim, R. F. Mason, US Pat.
3647915, 1971; d) R. F. Mason, US Pat. 3686351, 1972.
[30] W. Keim, in: Industrial Applications of Homogenous Catalysis
(Eds.: A. Mortreux, F. Petit), Dordrecht, 1988, pp. 335–347.
[34] K. Issleib, A. Tzschach, Chem. Ber. 1959, 92, 1118–1126.
[35] G. M. Sheldrick, Acta Crystallogr., Sect. A 2008, 64, 112–122.
Received: November 3, 2009
Published Online: January 15, 2010
1186
www.eurjoc.org
© 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Org. Chem. 2010, 1176–1186