A versatile methodology for the synthesis of α,β-unsaturated 3-iminophosphines

Article abstract of DOI:10.1002/chem.200802310

Fourteen new αβ-unsaturated β-chloroimines were synthesized from commercially available ketones using the Vilsmeier-Haack reagent, followed by Schiff-base condensation. Each imine was subsequently converted to an αβ-unsaturated 3-iminophosphine through either late-metal-catalyzed phosphorus-carbon cross-coupling or through an addition-elimina-tion sequence. Depending on the substituents present on the vinyl group, the resultant phosphines were isolated as either E or Z diastereomers with successful isolation of predominately single diastereomers for all fourteen new phosphines investigated. Full synthetic and spectroscopic details, as well as several X-ray crystal structures of these new imines and phosphines, are reported in addition to X-ray crystal structures of related palladium complexes.

Full text of DOI:10.1002/chem.200802310

DOI: 10.1002/chem.200802310
A Versatile Methodology for the Synthesis of a,b-Unsaturated
3-Iminophosphines
Andrew R. Shaffer and Joseph A. R. Schmidt*[a]
Abstract: Fourteen new a,b-unsaturat-
tion sequence. Depending on the sub-
stituents present on the vinyl group,
the resultant phosphines were isolated
as either E or Z diastereomers with
successful isolation of predominately
single diastereomers for all fourteen
ed b-chloroimines were synthesized
from commercially available ketones
using the Vilsmeier–Haack reagent,
followed by Schiff-base condensation.
Each imine was subsequently convert-
ed to an a,b-unsaturated 3-iminophos-
phine through either late-metal-cata-
lyzed phosphorus–carbon cross-cou-
pling or through an addition–elimina-
new phosphines investigated. Full syn-
thetic and spectroscopic details, as well
as several X-ray crystal structures of
these new imines and phosphines, are
reported in addition to X-ray crystal
structures of related palladium com-
plexes.
Keywords: imino compounds
palladium phosphines Schiff
bases · Vilsmeier–Haack reaction
·
·
·
Introduction
schemes for phosphine synthesis remains an important pur-
suit in the advancement of phosphine-based catalysis.
Phosphines are attractive ligands for late-metal-based cata-
lyst design; the strong bonds formed between phosphorus
and late metals provide for the stabilization of reactive
metal centers commonly found as intermediates in catalytic
cycles.[1] For example, the use of phosphine ligands in palla-
dium catalysis has circumvented the formation of palladium
black, one of the most common catalyst decomposition
pathways observed with this metal.[2] Additionally, phos-
phine-ligated metal complexes often display excellent air
and water stability, avoiding phosphine oxide formation due
to the strong interaction between the phosphine lone pair
and the metal center.[1] As current synthetic routes available
for the synthesis of substituted phosphines limit the specific
steric and electronic properties of phosphine-based ligands
somewhat, the discovery of new and general reaction
The development of phosphine chemistry has drawn
much attention because phosphines have been successfully
used as ancillary ligands for a variety of catalytic reactions,
including hydroamination,[3–5] hydrogenation,[6,7] allylic ami-
nation,[8–10] cycloaddition,[11] and cross-coupling.[12–15] While
aiming to achieve high catalyst activity in the above reac-
tions, control of molecular chirality is invaluable for phar-
maceutical applications and fine-chemical syntheses.[16,17]
Often, catalytic control of product chirality can be accom-
plished through the use of chiral metal complexes (enantio-
selective control) or by using specific diastereomers of metal
complexes displaying an even lower molecular symmetry
(diastereomeric control). The use of chiral phosphines has
played a strong role in enantioselective control, whereas un-
symmetric phosphine-containing chelating ligands (using
two phosphorus donor atoms or one phosphorus and one ni-
trogen atom) are important for diastereomeric control. The
formation of a single diastereomer by using mixed chelates
is also highly valuable as it allows for alternate mechanistic
pathways for asymmetric catalysis.
[a] A. R. Shaffer, Prof. Dr. J. A. R. Schmidt
Department of Chemistry, The University of Toledo
2801 W. Bancroft St. MS 602 Toledo, OH 43606-3390 (USA)
Fax : (+1)419-530-4033
Thus far, bidentate, chiral diphosphine-ligated catalysts
have realized success in a wide variety of asymmetric cata-
lytic reactions.[5,6,8–10,12,13,16–18] The biggest limitations of these
catalysts relate to substrate scope and catalyst activity.[16,17]
An alternate approach to asymmetric catalysis involves bi-
dentate ligands in which each donor atom has unique steric
and electronic properties. Asymmetric ligands of this type
E-mail: Joseph.Schmidt@utoledo.edu
Supporting Information for this article is available on the WWW
under http://dx.doi.org/10.1002/chem.200802310. It contains summa-
ries of crystal data, collection parameters, and ORTEP diagrams for
1
crystal structures of 2c–e, 2h, 2j, 2l, and 4; and a H NMR spectrum
for 1c.
2662
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

FULL PAPER
have displayed hemilability (partial decoordination),[19] re-
sulting in new and useful mechanistic pathways.[7,11,14,15,20–22]
We recently described the first example of a new class of bi-
dentate phosphine ligand, known as a 3-iminophosphine,
which contains a phosphine moiety tethered to an imine
through a vinylic backbone.[23] The presence of an a,b-unsa-
turated alkenyl backbone distinguished these species from
other known phosphine–imine ligands that have been con-
structed based on ortho-substituted phenyl groups.[7,11,21,22]
Palladium complexes supported by 3-iminophosphines are
active catalysts for the hydroamination of phenylacetylene
and 1,3-cyclohexadiene.[23] Herein, we report a versatile and
general method for the synthesis of a,b-unsaturated 3-imino-
phosphines involving a diverse array of substituents. Not
only are these phosphines expected to be effective chelating
ligands for late metals, but they also function as versatile
precursors to related compounds through the use of well-es-
tablished imine reactivity. For example, imine reduction[24,25]
or addition reactions[26–30] would convert the compounds re-
ported herein to the related amines or substituted amines,
respectively.
group in place of the phenyl group and yielded only the Z
isomer 1b.[34] In contrast, the use of propiophenone pro-
duced almost exclusively the E diastereomer of 1c (E/Z
9:1), due to the enhanced stabilization of the enol inter-
mediate.[32,33,35] We note that previous reports[32,33] of com-
1
pound 1c contain errors in the reported H NMR spectros-
copy data (see the Experimental Section for correct chemi-
cal shifts).[36] Compounds 1a–c form the backbone for our
synthesis of a wide range of a,b-unsaturated 3-iminophos-
phines.
Schiff-base condensation of 1a–c readily converted these
aldehydes to aldimines with various primary amines (2a–o;
Scheme 1; Table 1), including tert-butylamine, aniline, and
Table 1. Schiff-base condensation of b-chloroaldehydes (1a–c) to form
a,b-unsaturated b-chloroimines (2a–o).[a]
Entry
R1
R2
R3
Product
T
[8C]
t
Yield[b]
[%]
[h]
1
2
3
4
5
6
7
8
Ph
Ph
Ph
Ph
H
H
H
H
H
H
H
H
tBu
Ph
2,6-Me2Ph
2,6-Et2Ph
2,6-iPr2Ph
tBu
2a
2b[c]
2c
0
0
0
0
0
0
0
0
0
14
14
14
14
14
14
14
14
14
14
110
14
110
110
110
86
65
72
71
78
2d
2e
2 f
Ph
tBu
tBu
tBu
tBu
tBu
Ph
Ph
Ph
Ph
Ph
82
Ph
2g[d]
2h
2i
(62)[d] (4)
88
Results and Discussion
2,6-Me2Ph
2,6-Et2Ph
2,6-iPr2Ph
tBu
9
H
H
90
87
94
79
81
84
77
A wide range of a,b-unsaturated 3-iminophosphines have
been synthesized from commercially available, inexpensive
precursors using the new three-step, high-yield protocol pre-
sented herein. This methodology employs the Vilsmeier–
Haack reagent[31] to produce a,b-unsaturated b-chloroalde-
hydes (1a–c),[32–35] followed by a Schiff-base condensation to
yield a,b-unsaturated b-chloroimines (2a–o). The final con-
version to the desired a,b-unsaturated 3-iminophosphines
(3a–o) is effected by either a late-metal-catalyzed coupling
reaction (3a–e) or the direct substitution of chloride using
an alkali metal phosphide (3 f–o).
10
11
12
13
14
15
2j
2k
2l
2m
2n
2o
0
Me
Me
Me
Me
Me
25
25
25
25
25
Ph
2,6-Me2Ph
2,6-Et2Ph
2,6-iPr2Ph
[a] Reaction conditions: amine (1.1 equiv), 1a–c (1.0 equiv), diethyl ether
(30 mL). [b] Isolated yields. [c] 90 mL of diethyl ether. [d] Imine 2g was
observed as a component of the crude products, but was converted to the
addition product 4 in good yield (62%) upon workup.
The Vilsmeier–Haack reagent, generated in situ, is com-
monly employed to convert a ketone with an enolizable a
hydrogen (through its enol tautomer) into a vinyl chloride
while simultaneously adding an iminium group, thus extend-
ing the carbon framework by one unit.[35] Herein, the reac-
tion of the Vilsmeier–Haack reagent with acetophenone, pi-
nacolone, or propiophenone was used to generate the corre-
sponding b-chlorovinyl aldehydes after aqueous workup
(1a–c; Scheme 1). By using optimized conditions, compound
1a was produced in 75% yield with very high diastereose-
lectivity (Z/E 9:1), as previously reported.[32] The use of pi-
nacolone produced the related product with a tert-butyl
2,6-dialkylanilines.[37] The Z isomers of compounds 2a–e
were readily separated from the trace amounts of E diaste-
reomers produced from the condensation of the small
amount of E-1a initially present and were isolated in 65–
86% yield. Imines 2 f–j were found to produce only Z dia-
stereomers, as present in the initial aldehyde 1b. This group
1
of imines (2a–j) had very similar H NMR resonances for
their 1-aza-1,3-butadiene backbones (Z isomers in all cases),
with minor differences attributable to the electronic effects
of the substituents present. Excluding 2l, the condensation
reactions to produce 2k–o proceeded much slower due to
the methyl substitution of the backbone. For imine 2l,
workup allowed for isolation of exclusively the E diastereo-
mer, with the small amount (~10%) of Z isomer readily re-
moved by recrystallization. For 2m–o, attempted distillation
to remove the starting aldehyde and residual unreacted ani-
lines from the final products led to thermal isomerization of
the substituted vinyl group, resulting in approximately a 3:1
ratio of E/Z isomers. Thus, the crude products were used for
1
subsequent reactions (E/Z ratio of about 9:1). The H NMR
Scheme 1. Synthesis of a,b-unsaturated b-chloroimines (2a–o).
spectra for E imines 2k–o were significantly different from
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2663

J. A. R. Schmidt and A. R. Shaffer
those of the Z imines (2a–j), but trends in the resonances
were consistent within this group of E imines. Imines 2c–e,
h, j, and l were isolated as solids by recrystallization, and
the solid-state structures of these compounds were deter-
mined by X-ray crystallography (see the Supporting Infor-
mation). Overall, these solid-state structures showed that
the bond lengths and angles varied little throughout this
series; all bond lengths and angles were typical for organic
compounds of this type.[38,39]
a,b-unsaturated b-chloroimines (2a–e) in a stepwise fashion
to understand more fully the underlying chemistry in this
process. Initially, compound 2d was added to a palladium(0)
source, tetrakis(triphenylphosphine)palladium(0), at 08C in
toluene (Scheme 3). Oxidative addition to the metal center
Several aspects of the syntheses of imines 2a–o merit fur-
ther comment. In general, undesirable products were
formed when these reactions were run under high concen-
trations, whereas the reactions proceeded very slowly if they
were carried out too dilute. The optimized conditions de-
scribed herein provide for a reasonable reaction time while
minimizing the amount of byproducts formed. The reactions
involving unsubstituted aniline were especially challenging
and required very careful control of conditions and subse-
quent handling. The shelf life of product 2b was limited to
about 48 h when stored under ambient atmosphere; howev-
er, it was stable for several months under nitrogen. More-
over, imine 2g (tBuCCl=CHCH=NPh) could be observed in
the crude reaction mixtures, but its isolation proved untena-
ble. Attempted isolation by crystallization proved futile, be-
cause 2g reacts with leftover aniline from the condensation
reaction to yield the addition product 4 (Scheme 2). The
identity of 4 was confirmed by NMR spectroscopy, high-res-
olution mass spectrometry and X-ray crystallography.
Scheme 3. Oxidative addition of 2d to Pd0.
afforded a palladium(II) complex, 5, as well as two equiva-
lents of free triphenylphosphine, which were readily re-
moved in pentane washes. The 31P NMR spectrum for 5
showed a single resonance at d=24.3 ppm, indicating that
the two remaining triphenylphosphine ligands were equiva-
lent, and thus trans to one another. Additionally, the narrow
line width observed implied that 5 was not fluxional in solu-
tion. To confirm its connectivity, yellow crystals of 5 were
grown from a solution in toluene layered with pentane at
room temperature and its X-ray crystal structure was solved
(Figure 1). The triphenylphosphine ligands were trans to one
another, confirming the NMR spectroscopy assessment. Fur-
thermore, the stereochemistry of the C=C double bond was
retained in the Z diastereomer, with the imine carbon trans
to the phenyl substituent.
Scheme 2. Attempted isolation of 2g results in addition of aniline to
yield 4.
Our initial approach for the conversion of the a,b-unsatu-
rated b-chloroimines (2a–o) to phosphines involved treat-
ment with lithium diphenylphosphide (LiPPh2). We antici-
pated that 2a–o would undergo phosphide addition followed
by rapid chloride elimination, effecting conversion of the
chloro group to a diphenylphosphine. Attempts to use this
methodology for imines 2a–e proved unsuccessful because
multiple, unidentified phosphorus-containing products were
observed by 31P NMR spectroscopy. Similar results were ob-
served with sodium diphenylphosphide (NaPPh2). Addition
of diphenylphosphine (HPPh2) in the presence of triethyl-
amine or pyridine also yielded multiple products. In contrast,
when diphenyltrimethylsilylphosphine (Ph2PSiMe3) was used
as the phosphorus source, no reaction was observed at all.
Previous work by Beletskaya and coworkers has shown
that cross-coupling of Ph2PSiMe3 with vinylic halides can be
effected using either nickel or palladium catalysts with re-
tention of stereochemistry.[40,41] We investigated the use of
late-metal cross-coupling reactions for conversion of our
Figure 1. ORTEP diagram (50% thermal ellipsoids) of 5. Hydrogen
À
atoms omitted for clarity. Bond lengths [ꢁ]: N1=C1=1.273(3), C1 C2=
À
1.445(3), C2=C3=1.354(3), Pd1 C3=2.017(2). Bond angles [8]: P1-Pd1-
P2=176.2(1), C3-Pd1-Cl1=177.4(1), C1-C2-C3=122.6(2), N1-C1-C2=
123.4(2), N1-C1-C2-C3=179.2(2).
To investigate the metal-mediated phosphine coupling
step, one equivalent of Ph2PSiMe3 was added to
5
(Scheme 4), and the reaction was monitored by 1H NMR
2664
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

Iminophosphine Synthesis
FULL PAPER
Table 2. Metal-catalyzed cross-coupling of a,b-unsaturated b-chloro-
imines with Ph2PSiMe3.[a]
Entry
Reactant
Catalyst
[Pd
T
t
Conversion to 3[c]
[%]
[oC]
[h]
1
2
3
4
5
6
7
8
2d
2d
2a
2b
2c
2d
2e
2 f
2 f
2 f
2k
G
120
90
120
50
70
90
130
130
130
110
130
172
14
60
21
>99
>99
>99
85
[Ni
[Ni
[Ni
[Ni
[Ni
[Ni
[Ni
[Ni
[Ni
[Ni
ACHTUNGTRENNUNG
A
14
14
14
14
14
14
Scheme 4. Substitution of chloride with phosphide results in rapid reduc-
tive elimination, as observed by 31P{1H} NMR spectroscopy.
N
N
R
N
90
spectroscopy. After 10 min, the doublet at d=0.138 ppm
G
<5
<5
45
[42]
corresponding to the methyl groups of Ph2PSiMe3 was re-
9
10
11
R
158
38
158
placed by a sharp singlet representative of chlorotrimethyl-
ACHTUNGTRENNUNG
silane (Me3SiCl, d=0.175 ppm). Pronounced shifts for the
A
<5
1
alkenyl backbone resonances in the H NMR spectrum, as
[a] Reaction conditions: 2a–o (1.0 equiv), Ph2PSiMe3 (1.2 equiv), catalyst
well as changes in the 31P NMR spectrum were also ob-
served. Very similar results were observed when a more
nucleophilic phosphine source, lithium diphenylphosphide,
was used. We postulate that in both cases substitution of the
chloro ligand for a diphenylphosphide ligand occurs at the
palladium, with concomitant loss of Me3SiCl and LiCl. The
resultant complex is then unstable with respect to reductive
elimination, which occurs through the rapid formation of a
carbon–phosphorus bond. The final product (6) from this re-
action sequence was observed spectroscopically, and its
31P NMR spectrum consisted of two broad resonances at d=
24.5 and 25.8 ppm, which integrated in a ratio of 2:1. The
broad peaks observed are indicative of fluxionality in solu-
tion, which we attribute to rapid coordination/decoordina-
tion of the phosphine ligands. The 2:1 ratio of ligands agrees
well with the two triphenylphosphine ligands present for
each equivalent of 3-iminophosphine formed. When purifi-
cation of 6 by recrystallization was attempted, the only iso-
lated compound was tetrakis(triphenylphosphine)palladi-
um(0), a low solubility material that was readily generated
by the ligand coordination/decoordination processes occur-
ring in solution.
(5 mol%), toluene (50 mL). [b] 10 mol% [Ni
using H NMR spectroscopy.
R
1
After installation of the diphenylphosphino group into 3-
iminophosphines 3a–e, determination of the diastereomeric
configuration of these trisubstituted alkenes proved to be
relatively challenging. Simple coordination chemistry was
employed as one means for determination of the alkene ste-
reochemistry in 3a–e. Thus, phosphine 3b was readily coor-
dinated to palladium(II), supplied as the (allyl)palladium-
chloride dimer, to produce 7 (Scheme 5). X-ray quality crys-
Scheme 5. Coordination of 3b to [{PdACTHNUTRGNEN(UG allyl)Cl}2].
Given that the set of reactions utilized to produce 5 and 6
resulted in the regeneration of phosphine-coordinated palla-
dium(0) species in solution, we postulated that this phospho-
rus–carbon coupling reaction might be possible using only a
catalytic amount of palladium(0) reagent. To investigate this
reaction catalytically, it was important to use Ph2PSiMe3 as
the phosphine source because it was previously found to be
inert towards compounds 2a–e, unlike HPPh2, LiPPh2 or
NaPPh2. Initially, tetrakis(triphenylphosphine)palladium(0)
was employed as a catalyst for this coupling, but the reac-
tion proceeded very slowly (Table 2; entry 1). To achieve
faster reaction times, alternative nickel(0) sources were in-
vestigated. The use of tetrakis(triphenylphosphine)nickel(0)
as the metal catalyst gave better results than the analogous
palladium(0) complex due to the increased reactivity of the
nickel–ligand bonds (Table 2; entry 2), but ultimately we
found that replacing triphenylphosphine with 1,5-cycloocta-
diene (COD) as the auxiliary ligand increased the reaction
tals of this complex were grown from a layered solution of
tetrahydrofuran and pentane at room temperature. The crys-
tal structure of 7 displayed a square-planar palladium spe-
cies with the 3-iminophosphine ligand bound through only
the phosphorus (Figure 2). This structure allowed for defini-
tive assignment of the 3-iminophosphine diastereomer,
which was surprisingly found to be the E isomer (phospho-
rus atom trans to the imine). Normally, reductive elimina-
tion is expected to proceed with retention of configuration,
implying that in this case, the operable reaction mechanism
may be more complicated than initially anticipated. This iso-
merization proved to be general, leading to isolation of ex-
clusively the E diastereomers of compounds 3a–e (Table 3).
To help elucidate the causes for the alkene isomerization
observed in the coupling leading to 3a–e, various reaction
conditions were investigated. By performing the reaction in
the absence of light, it was found that a significant amount
of the Z isomer was formed, with an almost 1:1 ratio of Z/E
being the highest amount of Z isomer observed in any at-
tempt (3d). Even in the absence of light, increasing the re-
action times led once again to the production of more E dia-
rate dramatically. Thus, catalytic amounts of [NiACHTNUTRGNEUNG(cod)2]
proved to be the best way to convert imines 2a–e to the re-
lated 3-iminophosphines 3a–e (Table 2; entries 3–7).
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2665

J. A. R. Schmidt and A. R. Shaffer
the Z diastereomer would require an alternative synthetic
route in which the kinetic product could be favored.
In the case of imines 2 f–o (with R1 =tBu or R2 =Me),
metal-catalyzed cross-coupling of the vinyl chloride with
Ph2PSiMe3 was ineffective, with little or no conversion to
the desired 3-iminophosphine products (Table 2; entries 8–
11). Fortunately, the use of the initially proposed addition–
elimination sequence by direct reaction with LiPPh2 proved
to be a very successful means for the synthesis of these
imines. For the syntheses of 3 f–j, each of the a,b-unsaturat-
ed b-chloroimines (2 f–j) was added to a slight excess of
LiPPh2 at À788C and slowly allowed to warm to 08C. A
similar approach was used for 3k–o, but the reaction time
was considerably longer in most cases (Table 3; entries 11–
15). The ratio of 3-iminophosphine diastereomers was highly
dependent on the temperature and concentration at which
the addition occurred, and a select number of examples
demonstrated the formation of only a single isomer. When
two isomers were generated, additional heating after the re-
action was complete did not lead to product isomerization;
no change in the E/Z ratio was observed. As we have not
yet been able to fully isolate a single diastereomer of the b-
chloroimines 2m–o, the crude materials were used in the ad-
dition–elimination sequence to produce 3m–o. In all cases,
product workup led to isolation of the primary products as
clean, predominately single diastereomers (including 3m–o)
(Table 3). Confirmation of our diastereomeric assignments
in 3 f–o was achieved by crystallization of the unmetallated
phosphine. X-ray quality crystals of 3 f were grown from
pentane, and the crystal structure confirmed the product as
the Z diastereomer (the imine moiety is cis to the diphenyl-
phosphine and trans to the tert-butyl group; Figure 3). The
N1=C1 and C2=C3 bond lengths are consistent with typical
Figure 2. ORTEP diagram (50% thermal ellipsoids) of 7. Hydrogen
À
atoms omitted for clarity. Bond lengths [ꢁ]: C1=N1=1.278(3), C1 C2=
À
À
À
1.451(3), C2=C3=1.350(3), C3 P1=1.824(2), P1 Pd1=2.310(1), Pd1
À
À
Cl1=2.368(1), Pd1 C30=2.122(2), Pd1 C28=2.185(2). Bond angles [8]:
N1-C1-C2=120.0(2), C1-N1-C10=119.1(2), C1-C2-C3=123.5(2), C2-C3-
P1=119.4(2), P1-Pd1-Cl1=93.1(1), C30-Pd1-C28=68.1(1), C30-C29-
C28=129.6(4).
Table 3. Conversion of a,b-unsaturated b-chloroimines (2a–o) to 3-imino-
phosphines (3a–o).[a]
Entry
Product
T [8C]
t [h]
Method
Yield[b] [%]
1
2
3
4
5
6
7
8
3a
3b
3c
3d
3e
3 f
3g
3h
3i
3j
3k
3l
3m
3n
3o
110
110
110
110
110
À78
À78
À78
À78
À78
À78
À78
À78
À78
À78
14
14
14
14
14
14
14
14
14
A
A
A
A
A
B
B
B
B
B
B
B
B
B
B
75
71
61
69
74
57
N/A[c]
67
41
44
63
52
48
58
71
9
10
11
12
13
14
15
14
144[d]
14
144[d]
144[d]
144[d]
[a] Reaction conditions (Method A): 2a–e (1.0 equiv), Ph2PSiMe3
(1.2 equiv), [Ni(cod)2] (5 mol%), toluene (30 mL). Reaction conditions
ACHTUNGTRENNUNG
(Method B): 2 f–o (1.0 equiv), Ph2PLi (1.3 equiv), toluene (20 mL).
[b] Isolated yield. [c] 2g was unavailable; thus 3g was not attempted.
[d] Reaction was stirred at À788C for 14 h and then at ambient tempera-
ture for 130 h.
stereomer at the expense of the Z isomer. The isolated E
isomer did not isomerize to the Z isomer under any condi-
tions tested, such as varying light, temperature, or the pres-
ence/absence of metal catalysts. Thus, we conclude that the
E diastereomer of 3-iminophosphines 3a–e is the thermody-
namic product of this reaction and an effective synthesis of
Figure 3. ORTEP diagram (50% thermal ellipsoids) of 3 f. Hydrogen
À
atoms are omitted for clarity. Bond lengths [ꢁ]: N1=C1=1.274(2), C1
À
C2=1.465(2), C2=C3=1.344(2), C3 P1=1.847(2). Bond angles [8]: C1-
N1-C8=121.0(2), N1-C1-C2=117.7(2), C1-C2-C3=129.5(2), C2-C3-P1=
125.9(1).
2666
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

Iminophosphine Synthesis
FULL PAPER
À
further purification. 1H and 13C NMR spectroscopy data were obtained
on a 600 MHz Inova NMR spectrometer at ambient temperature at 599.9
and 150.9 MHz, respectively. 31P NMR data were obtained on a 400 MHz
Varian NMR spectrometer at ambient temperature at 161.9 MHz.
1H NMR shifts are given relative to CHCl3 (7.26 ppm) and 13C NMR
shifts are given relative to CDCl3 (77.3 ppm). 31P NMR data were exter-
nally referenced to 0.00 ppm with 5% H3PO4 in D2O. For IR spectros-
copy, liquid samples were taken neat and solid samples were prepared as
Nujol mulls and taken between KBr plates on a Perkin–Elmer XTL
FTIR spectrophotometer. Melting points were observed on a capillary
melting point (Uni-Melt) apparatus in sealed capillary tubes and are un-
corrected. Boiling points were obtained at atmospheric pressure unless
otherwise noted. High-resolution mass spectra were obtained by using
electron impact ionization unless otherwise noted, by the Mass Spectrom-
etry Laboratory at the University of Illinois, Urbana, IL. Elemental anal-
yses were determined by Columbia Analytical Services, Tucson, AZ. X-
ray structure determinations were performed at the Ohio Crystallograph-
ic Consortium housed at The University of Toledo. Bis(1,5-cyclooctadie-
ne)nickel(0),[45] tetrakis(triphenylphosphine)nickel(0),[46] sodium diphe-
nylphosphide,[47] lithium diphenylphosphide,[48] and diphenyl(trimethylsi-
lyl)phosphine[42] were prepared as previously reported.
double bonds, and the C1 C2 bond length was comparable
with related species.[43,44]
Overall, the syntheses of 3-iminophosphines 3a–o pro-
ceeded readily with a wide range of substituents (Table 3).
For the b-phenyl-b-chloroimines 2a–e, phosphination was
best accomplished by using a late-metal-catalyzed cross-cou-
pling reaction, whereas the remaining b-chloroimines 2 f–o
were readily phosphinated by a direct addition–elimination
sequence. The 3-iminophosphines 3a–e were isolated as ex-
clusively E diastereomers and exhibited 31P NMR resonan-
ces near d=5 ppm. On the other hand, products 3 f–j were
produced as exclusively Z diastereomers with 31P NMR res-
onances in the vicinity of d=À20 ppm. Finally, 3-iminophos-
phines 3k–o, with methyl branches in their backbones, were
isolated as pure E diastereomers exhibiting 31P NMR reso-
nances near d=À7 ppm. These resonances are representa-
tive of the differing electronic contributions from the alkene
substituents, as well as the diastereomeric configurations of
the compounds isolated.
General procedure for the synthesis of 3-chloropropenals (1a–c): PCl5
(36.44 g, 175.0 mmol) was added to N,N-dimethylformamide (29.24 g,
400.0 mmol) and stirred at 258C for 2 h. The mixture was cooled to 08C,
and a mixture of the ketone (100.0 mmol) and N,N-dimethylformamide
(7.309 g, 100.0 mmol) was added. The resulting mixture was stirred at
368C for 12 h, then poured over ice, basified with sodium bicarbonate,
and extracted with Et2O (3ꢂ100 mL). The combined organic extracts
were washed with a saturated aqueous solution of NaHCO3 (2ꢂ100 mL)
and a saturated aqueous solution of NaCl (100 mL), dried over MgSO4
(10 min), filtered, and the solvent was evaporated. The E/Z ratios were
1:10 (1a) 1:20 (1b) and 9:1 (1c).
Conclusion
Several new a,b-unsaturated 3-iminophosphines and their
corresponding a,b-unsaturated b-chloroimine precursors
were synthesized by two very distinctive, yet conventional
methods. A late-metal-catalyzed phosphorus–carbon cross-
coupling method was employed in the synthesis of 3a–e.
Surprisingly, this reaction led to alkene isomerization and
these compounds were isolated as exclusively E diastereo-
mers. The remaining 3-iminophosphines (3 f–o) were synthe-
sized by using an addition–elimination reaction sequence.
Diastereomeric isomerization of 3 f–o was prevented by
careful regulation of the temperature and concentration at
which the addition occurred, allowing for the isolation of
single diastereomers of these products with retention of the
double-bond configuration observed in the precursor imines.
The use of these a,b-unsaturated 3-iminophosphines as li-
gands for the development of late-metal catalysts remains
an area of active investigation in our research laboratory.
1a:[32] Red liquid (12.499 g, 74.48%); b.p. 528C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) Z isomer: d=10.23 (d, 3J
ACHTUNGTRENNUNG
3
3J
matic resonances obscured, 6.54 ppm (d, 3J
13C{1H} NMR (150.9 MHz, CDCl3)
isomer: d=191.7, 152.6, 135.7,
ACHUTGTNRENNUG(H,H)=7.2 Hz, 1H); E isomer: d=9.48 (d, JACHTUNGTRENNUNG
AHCTUNGTRENNUNG
Z
132.1, 129.1, 127.4, 124.6 ppm; IR (KBr) n˜ =3060 (w), 2919 (w), 2842 (w),
2749 (w), 1752 (w), 1669 (s), 1601 (s), 1570 (m), 1492 (w), 1446 (m), 1311
(w), 1228 (m), 1168 (w), 1160 (w), 1129 (s), 1077 (w), 1028 (w), 1001 (w),
926 (w), 886 (w), 837 (w), 761 (s), 734 (w), 703 (m), 685 (m), 628 (m),
583 cmÀ1 (m); HRMS: m/z calcd for C9H6ClO: 165.01072 [MÀH]+;
found: 165.01078.
1
1b:[34] Yellow liquid (12.371 g, 84.01%); b.p. 948C; H NMR (599.9 MHz,
CDCl3) d=10.00 (d, 3J(H,H)=5.6 Hz, 1H), 6.10 (d, 3J
ACTHNUTRGENNUG ACHUTTGNREN(NUGN H,H)=5.6 Hz,
1H), 1.20 ppm (s, 9H); 13C{1H} NMR (150.9 MHz, CDCl3): d=192.8,
167.2, 123.2, 40.2, 28.5 ppm; IR (KBr) n˜ =3080 (w), 3062 (w), 3017 (w),
2963 (s), 2917 (m), 2863 (m), 1953 (w), 1898 (w), 1808 (w), 1677 (m),
1659 (m), 1610 (s), 1487 (w), 1473 (m), 1441 (m), 1370 (s), 1320 (m), 1284
(m), 1266 (m), 1211 (s), 1175 (w), 1152 (w), 1076 (w), 1040 (m), 1022
(m), 958 (w), 931 (w), 908 (m), 890 (m), 845 (w), 818 (w), 754 (s), 696 (s),
678 (m), 642 (w), 610 cmÀ1 (m); HRMS (ESI): m/z calcd for C7H10ClO:
145.0420 [MÀH]+; found: 145.0421.
Experimental Section
General: Compounds 1, 2, and 4 were synthesized under an ambient at-
mosphere. Compounds 3 and 5–7 were synthesized by using standard
Schlenk and dry box techniques. n-Butyllithium (1.6m in hexanes), tetra-
kis(triphenylphosphine)palladium(0), (allyl)palladium(II) chloride dimer,
and diphenylchlorophosphine were purchased from Strem and used as re-
ceived. CDCl3 was purchased from Cambridge Isotope Laboratories and
vacuum distilled from CaH2. Pentane, toluene, and tetrahydrofuran were
purchased from Fisher and purified by passage through a column of acti-
vated 4 ꢁ molecular sieves and degassed with nitrogen prior to use. Di-
ethyl ether was purified by passage through a column of activated alumi-
na and degassed with nitrogen prior to use. 1,4-Dioxane was heated at
reflux over sodium and distilled under nitrogen. Dimethylformamide and
dichloromethane were purchased from Fisher and used without further
purification. Acetophenone, propiophenone, pinacolone, phosphorus pen-
tachloride, tert-butylamine, aniline, 2,6-dimethylaniline, 2,6-diethylaniline,
and 2,6-diisopropylaniline were purchased from Acros and used without
1c:[32, 33,35] Yellow liquid (12.574 g, 69.61%); b.p. 588C (0.05 mmHg);
1H NMR (599.9 MHz, CDCl3) E isomer: d=9.48 (s, 1H), 7.42–7.50 (m,
5H), 2.09 ppm (s, 3H); Z isomer: d=10.41 (s, 1H), 7.42–7.50 (m, 5H),
1.85 ppm (s, 3H); 13C{1H} NMR (150.9 MHz, CDCl3) Z isomer: d=190.7,
154.8, 136.5, 136.0, 130.6, 130.3, 128.7, 13.6 ppm; IR (KBr) n˜ =3053 (w),
3026 (w), 2962 (w), 2918 (w), 2845 (m), 2746 (m), 1957 (w), 1894 (w),
1812 (w), 1726 (m), 1672 (s), 1609 (s), 1595 (m), 1586 (m), 1482 (m), 1442
(s), 1388 (m), 1374 (m), 1324 (m), 1288 (m), 1247 (s), 1220 (m), 1175 (w),
1152 (w), 1071 (m), 1017 (s), 967 (w), 926 (m), 899 (s), 863 (m), 814 (w),
764 (s), 714 (s), 696 (s), 628 cmÀ1 (m); HRMS: m/z calcd for C10H8ClO:
179.02637 [MÀH]+; found: 179.02667.
General procedure for the synthesis of a,b-unsaturated b-chloroimines
(2a–o): A solution of primary amine (6.00 mmol) in Et2O (10 mL) was
added slowly at 08C to
a stirred solution of the 3-chloropropenal
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2667

J. A. R. Schmidt and A. R. Shaffer
(5.00 mmol) in Et2O (20 mL). The resulting mixture was stirred for 12 h,
gradually warming to room temperature, dried over MgSO4, filtered, and
the solvent evaporated. The E/Z ratios were 1:10 (2a–e) 1:20 (2 f–j) and
9:1 (2k–o). The E/Z ratios decreased to 3:1 (2m–o) due to isomerization
during attempted purification by distillation. Thus, the crude products
were used for successive reactions.
ACTHNGUTERNNUG
3J(H,H)=6.0 Hz, 1H), 1.194 (s, 9H), 1.188 ppm (s, 9H); 13C{1H} NMR
(150.9 MHz, CDCl3): d=155.3, 155.0, 122.7, 57.9, 39.7, 29.9, 28.8 ppm; IR
(KBr) n˜ =2968 (s), 2926 (m), 2874 (m), 1706 (w), 1659 (w), 1633 (s), 1576
(w), 1477 (m), 1462 (m), 1389 (w), 1358 (m), 1296 (w), 1254 (m), 1233
(m), 1213 (m), 1150 (w), 1103 (w), 1082 (w), 1026 (w), 974 (m), 854 (m),
797 (m), 766 (w), 652 cmÀ1 (m); HRMS: m/z calcd for C11H20NCl:
201.12842 [M]+; found: 201.12825.
2a: Red liquid (0.959 g, 86.4%); b.p. 828C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) d=8.45 (d, 3J
A
2g: Yellow solid; 1H NMR (599.9 MHz, CDCl3) d=8.54 (d, 3J
ACHTUNGTRENNUNG
N
9.0 Hz, 1H), 7.38 (t, 3J
A
ACHTUNGTRENNUNG
9H); 13C{1H} NMR (150.9 MHz, CDCl3): d=154.8, 141.0, 137.0, 130.1,
128.8, 126.8, 125.8, 58.4, 29.9 ppm; IR (KBr) n˜ =3054 (w), 2962 (s), 2921
(m), 2850 (w), 2328 (m), 1790 (w), 1765 (w), 1734 (w), 1719 (w), 1693
(w), 1673 (m), 1647 (m), 1616 (s), 1591 (m), 1555 (m), 1534 (m), 1488
(m), 1448 (m), 1360 (m), 1310 (w), 1220 (m), 1151 (m), 1071 (w), 1027
(w), 997 (w), 957 (w), 878 (m), 858 (m), 758 (s), 689 cmÀ1 (m); HRMS:
m/z calcd for C13H15NCl: 220.08930 [MÀH]+; found: 220.08930.
1H), 7.19 (d, 3J
G
ACHTUNGTRENNUNG
1.28 ppm (s, 9H).
2h: Yellow powder, which was recrystallized from pentane to yield
yellow crystals (1.097 g, 87.9%); m.p. 46–478C; 1H NMR (599.9 MHz,
CDCl3) d=8.28 (d, 3J
(H,H)=8.4 Hz, 1H), 7.05 (d, 3J
ACHUTGTNRENNUG CAHTUNGTRENNUNG
2H), 6.94 (t, 3J(H,H)=7.8 Hz, 1H), 6.62 (d, 3J
A
A
(s, 6H), 1.31 ppm (s, 9H); 13C{1H} NMR (150.9 MHz, CDCl3): d=162.3,
158.0, 151.0, 127.9, 126.8, 123.7, 121.8, 39.6, 28.4, 18.2 ppm; IR (Nujol)
n˜ =3061 (w), 3009 (m), 2926 (s), 2864 (s), 1627 (m), 1586 (w), 1462 (s),
1379 (m), 1358 (m), 1254 (m), 1192 (m), 1150 (m), 1088 (w), 1026 (w),
997 (w), 969 (m), 855 (m), 829 (w), 798 (w), 766 (m), 709 (m), 637 (m),
606 cmÀ1 (w); HRMS: m/z calcd for C15H19NCl: 248.12060 [MÀH]+;
found: 248.12064.
2b: Yellow solid, which was recrystallized from diethyl ether to yield
yellow-orange crystals (0.784 g, 64.9%); m.p. 65–668C; 1H NMR
(599.9 MHz, CDCl3) d=8.72 (d, 3J
ACHTUNGTRENNUNG
2H), 7.44 (m, 3H), 7.42 (t, 3J
7.2 Hz, 1H), 7.25 (d, 3J
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
8.4 Hz, 1H); 13C{1H} NMR (150.9 MHz, CDCl3): d=159.7, 130.7, 129.5
(2C), 129.0 (2C), 127.1 (2C), 125.2 (2C), 121.4 ppm; IR (Nujol) n˜ =3054
(w), 2915 (s), 2855 (s), 2329 (m), 1956 (w), 1886 (w), 1871 (w), 1737 (w),
1672 (m), 1653 (m), 1603 (s), 1578 (s), 1558 (s), 1533 (m), 1518 (w), 1374
(w), 1350 (m), 1320 (w), 1245 (m), 1225 (s), 1191 (w), 1166 (s), 1101 (w),
1076 (m), 1022 (m), 997 (m), 967 (m), 898 (m), 868 (s), 763 (s), 684 cmÀ1
(s); HRMS: m/z calcd for C15H11NCl: 240.05800 [MÀH]+; found:
240.05812.
2i: Yellow liquid (1.250 g, 89.9%); b.p. 888C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) d=8.25 (d, 3J
ACHTUNGTRENNUNG
3J
7.8 Hz, 1H), 2.47 (q, 3J
3J
G
E
ACHTUNGTRENNUNG
158.3, 133.4, 126.5, 126.3, 124.4, 122.2, 40.1, 28.9, 24.8, 15.1 ppm; IR
(KBr) n˜ =3060 (m), 2959 (s), 2932 (s), 2867 (s), 2355 (w), 1916 (w), 1852
(w), 1793 (w), 1678 (w), 1628 (s), 1586 (m), 1449 (s), 1394 (w), 1357 (m),
1289 (w), 1248 (m), 1206 (m), 1183 (m), 1151 (m), 1100 (m), 1077 (w),
1059 (w), 1026 (w), 962 (m), 852 (m), 838 (m), 802 (m), 756 (s), 706 (m),
637 (m), 600 cmÀ1 (s); HRMS: m/z calcd for C17H24NCl: 277.1597 [M]+;
found: 277.1598.
2c: Red-orange solid, which was recrystallized from pentane at À258C to
yield red-orange crystals (0.966 g, 71.7%); m.p. 55–568C; 1H NMR
(599.9 MHz, CDCl3) d=8.45 (d, 3J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
13C{1H} NMR (150.9 MHz, CDCl3): d=162.1, 151.6, 144.1, 136.7, 130.7,
128.9, 128.4, 127.3, 127.1, 125.1, 124.4, 18.7 ppm; IR (Nujol) n˜ =3176 (w),
3057 (w), 2920 (s), 2847 (s), 2728 (w), 2675 (w), 1677 (w), 1613 (m), 1590
(m), 1527 (w), 1461 (s), 1374 (m), 1310 (w), 1223 (m), 1187 (w), 1155
(m), 1086 (w), 1031 (w), 999 (w), 979 (w), 970 (w), 892 (w), 851 (w), 832
(w), 760 (m), 709 (m), 681 (m), 650 cmÀ1 (w); HRMS: m/z calcd for
C17H15NCl: 268.08930 [MÀH]+; found: 268.08938.
2j: Yellow powder, which was recrystallized from pentane to yield
yellow crystals (1.327 g, 86.7%); m.p. 66–688C; 1H NMR (599.9 MHz,
CDCl3) d=8.22 (d, 3J
2H), 7.11 (t, 3J
(sept, 3J(H,H)=6.6 Hz, 2H), 1.31 (s, 9H), 1.17 ppm (d, 3J
ACHTUNGTRENNUNG
(H,H)=8.4 Hz, 1H), 7.15 (d, 3J
ACHUTGTNRENNUG CAHTUNGTRENNUNG
ACHUTNGRENNUG CAHTUNGTRENNUNG
(H,H)=7.8 Hz, 1H), 6.57 (d, 3J
T
12H); 13C{1H} NMR (150.9 MHz, CDCl3): d=162.4, 158.3, 138.0, 124.6,
123.3, 122.1, 118.8, 40.1, 28.9, 28.0, 23.9 ppm; IR (Nujol) n˜ = 3061 (w),
2963 (s), 2919 (s), 2857 (s), 2723 (w), 1921 (w), 1859 (w), 1792 (w), 1721
(w), 1668 (w), 1624 (s), 1606 (m), 1588 (m), 1464 (s), 1437 (m), 1379 (m),
1361 (m), 1321 (m), 1250 (m), 1206 (w), 1179 (w), 1152 (m), 1108 (w),
1094 (w), 1059 (w), 1041 (w), 1023 (w), 961 (m), 930 (w), 903 (w), 881
(w), 859 (m), 832 (w), 801 (m), 757 (s), 721 (w), 698 (w), 646 (m),
601 cmÀ1 (m); HRMS: m/z calcd for C19H28NCl: 305.19102 [M]+; found:
305.19097.
2d: Yellow powder, which was recrystallized from pentane to yield
orange crystals (1.052 g, 70.7%); m.p. 80–818C; 1H NMR (599.9 MHz,
CDCl3) d=8.45 (d, 3J
N
3
(m, 3H), 7.23 (d, J
U
1H), 2.53 (q, 3J(H,H)=7.8 Hz, 4H), 1.18 ppm (t, 3J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
13C{1H} NMR (150.9 MHz, CDCl3): d=162.0, 150.8, 144.3, 136.7, 133.4,
130.9, 129.0, 127.2, 126.6, 126.5, 124.9, 25.0, 15.2 ppm; IR (Nujol) n˜ =3054
(w), 2915 (s), 2845 (s), 2329 (m), 1772 (w), 1717 (w), 1697 (w), 1673 (w),
1653 (w), 1603 (s), 1578 (m), 1558 (m), 1543 (w), 1519 (w), 1489 (m),
1374 (m), 1240 (m), 1220 (m), 1156 (s), 1101 (m), 1076 (w), 1022 (w), 992
(w), 893 (m), 848 (m), 808 (m), 763 (s), 708 (m), 684 (m), 669 cmÀ1 (m);
HRMS: m/z calcd for C19H20NCl: 297.1284 [M]+; found: 297.1281.
2k: Orange liquid (1.103 g, 93.6%); b.p. 308C (0.10 mmHg); 1H NMR
(599.9 MHz, CDCl3) E isomer: d=7.88 (s, 1H), 7.34–7.37 (m, 5H), 2.22
(s, 3H), 1.10 ppm (s, 9H); 13C{1H} NMR (150.9 MHz, CDCl3): d=155.2,
139.8, 137.9, 134.7, 130.1, 129.2, 128.4, 57.6, 29.9, 15.9 ppm; IR (KBr) n˜ =
3221 (w), 3084 (w), 3058 (w), 3021 (w), 2966 (s), 2930 (m), 2866 (m),
2737 (w), 1952 (w), 1897 (w), 1810 (w), 1718 (w), 1677 (m), 1659 (m),
1617 (s), 1594 (m), 1575 (w), 1485 (w), 1471 (m), 1443 (m), 1375 (m),
1355 (m), 1324 (m), 1283 (m), 1260 (m), 1210 (s), 1173 (w), 1154 (w),
1099 (w), 1076 (w), 1039 (m), 1021 (m), 957 (w), 929 (m), 911 (m), 897
(m), 847 (w), 814 (w), 778 (w), 760 (s), 700 (s), 672 (m), 636 (m),
613 cmÀ1 (m); HRMS: m/z calcd for C14H17NCl: 234.10495 [MÀH]+;
found: 234.10516.
2e: Yellow powder, which was recrystallized from pentane to yield
yellow crystals (1.276 g, 78.3%); m.p. 117–1188C; 1H NMR (599.9 MHz,
CDCl3) d=8.42 (d, 3J
G
3
(m, 3H), 7.23 (d, J
N
1H), 2.99 (sept, 3J
C
12H); 13C{1H} NMR (150.9 MHz, CDCl3): d=161.7, 149.5, 144.2, 137.9,
136.6, 130.7, 128.9, 127.2, 127.1, 124.8, 123.4, 28.1, 23.9 ppm; IR (Nujol)
n˜ =3064 (w), 3014 (w), 2964 (s), 2855 (s), 2358 (m), 2328 (m), 1772 (w),
1737 (w), 1697 (m), 1653 (w), 1608 (s), 1583 (m), 1558 (m), 1494 (m),
1379 (m), 1360 (m), 1320 (w), 1250 (m), 1220 (m), 1191 (m), 1156 (m),
1106 (w), 1076 (w), 898 (w), 873 (m), 828 (w), 763 (s), 709 (m), 689 (m),
664 cmÀ1 (m); HRMS: m/z calcd for C21H24NCl: 325.1597 [M]+; found:
325.1600.
2l: Yellow solid, which was recrystallized from pentane to yield yellow
1
crystals (1.012 g, 79.2%); m.p. 72–748C; H NMR (599.9 MHz, CDCl3) E
isomer: d=8.09 (s, 1H), 7.40–7.44 (m, 5H), 7.31 (t, 3J
ACHTUNGTRENNUNG
2H), 7.17 (t, 3J(H,H)=7.2 Hz, 1H), 7.00 (d, 3J
ACTHNUGTRENNUGN ACHTUNGTRENNNUG
(s, 3H); 13C{1H} NMR (150.9 MHz, CDCl3): d=159.7, 152.3, 143.9, 137.6,
134.8, 130.1, 129.7, 129.3, 128.7, 126.1, 121.1, 15.7 ppm; IR (Nujol) n˜ =
3051 (w), 2962 (s), 2927 (s), 2856 (s), 2722 (w), 2357 (w), 1605 (w), 1579
(m), 1481 (m), 1459 (m), 1370 (m), 1312 (w), 1286 (w), 1263 (w), 1223
2 f: Yellow liquid (0.825 g, 82.5%); b.p. 368C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) d=8.17 (d, 3J
ACTHNUTRGNE(UNG H,H)=6.0 Hz, 1H); 6.20 (d,
2668
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

Iminophosphine Synthesis
FULL PAPER
(w), 1201 (m), 1161 (w), 1077 (w), 1019 (w), 970 (w), 930 (w), 899 (m),
846 (w), 757 (s), 721 (w), 686 (m), 628 cmÀ1 (m); HRMS: m/z calcd for
C16H13NCl: 254.0736 [MÀH]+; found: 254.0738.
À788C for 10 min. The a,b-unsaturated b-chloroimine was added to the
lithium diphenylphosphide and stirred for an additional 14 h, slowly
warming to ambient temperature. The solvent was evaporated and the
crude product was triturated with pentane (10 mL). The product was ex-
tracted from the leftover LiPPh2 with pentane (3ꢂ25 mL). 3a–f, 3h, and
3k–o were recrystallized from pentane or diethyl ether. The ratios of E/Z
were 20:1 (3a–e), 1:25 (3 f–j) and 10:1 (3k–o).
2m: Red liquid (1.150 g, 81.0%); b.p. >1708C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) E isomer: d=7.77 (s, 1H), 7.36–7.37 (m, 5H), 7.00
(d, 3J(H,H)=7.8 Hz, 2H), 6.90 (t, 3J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
3a: Tan solid (0.416 g, 74.6%); m.p. 128–1308C; 1H NMR (599.9 MHz,
A
ACHTUNGTRENNUNG
CDCl3) d=7.88 (d, 3J
A
R
ACHTUNGTRENNUNG
2.16 ppm (s, 6H); 13C{1H} NMR (150.9 MHz, CDCl3) E isomer: d=161.7,
151.2, 143.9, 137.5, 134.6, 129.9, 129.6, 128.6, 128.2, 127.0, 123.9, 18.6,
15.4 ppm; Z isomer: d=163.1, 151.5, 138.7, 132.0, 130.3, 129.4, 129.2,
128.6, 128.3, 127.1, 124.1, 18.9, 16.2 ppm; IR (KBr) n˜ =3198 (w), 3060
(m), 3015 (m), 2951 (m), 2914 (m), 2850 (m), 2722 (w), 2034 (w), 1953
(w), 1912 (w), 1848 (w), 1806 (w), 1770 (w), 1692 (w), 1614 (s), 1587 (s),
1536 (w), 1468 (s), 1440 (s), 1376 (m), 1358 (m), 1316 (w), 1284 (m), 1266
(m), 1220 (m), 1193 (s), 1161 (w), 1091 (m), 1074 (w), 1028 (s), 987 (w),
964 (w), 895 (s), 844 (m), 762 (s), 721 (m), 698 (s), 661 (m), 629 (m),
601 cmÀ1 (m); HRMS: m/z calcd for C18H17NCl: 282.10495 [MÀH]+;
found: 282.10480.
3J
3J
C
ACHTUNGTRENNUNG
3
3
ACHUTGTNREN(UNG H,H)=7.2 Hz, 1H), 6.20 (dd, JACHTUNGTRENNUNG(H,H)=
A
(150.9 MHz, CDCl3): d=156.5, 153.3 (d, 1J
1J(P,C)=21.0 Hz), 135.6 (d, 2J
130.6 (d, 2J
3J
ACHTUNGTRENNUNG
G
E
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
CDCl3): d=4.7 ppm; IR (Nujol) n˜ =3051 (w), 2962 (s), 2918 (s), 2847 (s),
2722 (w), 2689 (w), 1956 (w), 1885 (w), 1810 (w), 1663 (w), 1614 (m),
1579 (w), 1459 (s), 1436 (m), 1374 (m), 1307 (w), 1259 (w), 1210 (m),
1183 (w), 1156 (w), 1133 (m), 1092 (m), 1023 (m), 1000 (w), 936 (w), 918
(w), 890 (w), 803 (w), 785 (w), 767 (m), 739 (m), 693 cmÀ1 (s); HRMS:
m/z calcd for C25H26NP: 371.1803 [MÀH]+; found: 371.1802.
2n: Red liquid (1.313 g, 84.2%); b.p. >1708C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) E isomer: d=7.82 (s, 1H), 7.36–7.40 (m, 5H), 7.06
(d, 3J
3J
Z isomer: d=8.65 (s, 1H), 7.50 (d, J
3J(H,H)=7.2 Hz, 3J(H,H)=7.8 Hz, 2H), 7.41 (t, 3J
7.11 (d, 3J(H,H)=7.8 Hz, 2H), 7.05 (t, 3J
(H,H)=7.8 Hz, 1H), 2.51 (q,
3J(H,H)=7.2 Hz, 4H), 2.14 (s, 3H), 1.19 ppm (t, 3J
(H,H)=7.2 Hz, 6H);
13C{1H} NMR (150.9 MHz, CDCl3)
isomer: d=161.1, 150.4, 143.8,
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
(H,H)=7.2 Hz, 2H), 7.00 (t, 3J
3b: Red solid (0.419 g, 71.4%); m.p. 128–1318C; 1H NMR (599.9 MHz,
CDCl3) d=8.08 (d, 3J
ACHTUNGTRENNUNG
R
ACHTUNGTRENNUNG
3
AHCTUNGTRENNUNG
E
E
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
E
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
E
AHCTUNGTRENNUNG
121.2 ppm; 31P{1H} NMR (161.9 MHz, CDCl3): d=5.8ppm; IR (Nujol)
n˜ =3054 (m), 3017 (m), 2954 (s), 2912 (s), 2850 (s), 2724 (w), 2682 (w),
1954 (w), 1896 (w), 1818 (w), 1776 (w), 1634 (w), 1603 (m), 1582 (w),
1477 (s), 1462 (s), 1430 (m), 1304 (w), 1263 (w), 1210 (w), 1189 (m), 1153
(w), 1137 (m), 1090 (m), 1069 (m), 1027 (m), 1001 (w), 945 (w), 933 (w),
896 (w), 839 (m), 797 (w), 760 (m), 739 (m), 718 (w), 697 (s), 603 (m),
551 (s), 509 cmÀ1 (s); HRMS: m/z calcd for C27H22NP: 391.1490 [M]+;
found: 391.1490.
137.5, 134.6, 132.9, 129.8, 129.6, 128.7, 126.4, 124.1, 24.9, 15.4, 14.9 ppm;
Z isomer d=162.5, 150.8, 139.4, 138.6, 133.1, 131.9, 129.4, 129.2, 128.6,
126.5, 124.3, 25.0, 16.2, 14.9 ppm; IR (KBr) n˜ =3062 (m), 3018 (m), 2953
(s), 2924 (s), 2864 (s), 1700 (w), 1616 (s), 1592 (s), 1488 (m), 1448 (s),
1374 (m), 1320 (w), 1285 (m), 1260 (m), 1226 (w), 1186 (s), 1166 (w),
1102 (m), 1077 (w), 1062 (w), 1038 (m), 1023 (m), 968 (w), 929 (w), 894
(m), 870 (w), 850 (m), 800 (w), 761 (s), 721 (m), 693 (s), 666 cmÀ1 (m);
HRMS: m/z calcd for C20H21NCl: 310.13625 [MÀH]+; found: 310.13632.
2o: Red liquid (1.314 g, 77.3%); b.p. >1708C (0.05 mmHg); 1H NMR
(599.9 MHz, CDCl3) E isomer: d=7.75 (s, 1H), 7.33–7.35 (m, 5H), 7.08
3c: Red liquid (0.383 g, 60.8%); 1H NMR (599.9 MHz, CDCl3) d=7.71
(d, 3J
G
G
(d, 3J
3J
Z isomer: d=8.60 (s, 1H), 7.50 (d, J
3J(H,H)=7.2 Hz, 3J(H,H)=7.8 Hz, 2H), 7.40 (t, 3J
7.17 (d, 3J(H,H)=7.8 Hz, 2H), 7.11 (t, 3J
(H,H)=7.8 Hz, 1H), 2.94 (sept,
3J
(H,H)=6.6 Hz, 2H), 2.14 (s, 3H), 1.21 ppm (d, J
13C{1H} NMR (150.9 MHz, CDCl3)
isomer: d=161.3, 150.4, 149.3,
ACHTUNGTRENNUNG ACHTUNGTRENN(UGN H,H)=7.2 Hz, 1H), 2.85 (sept,
(H,H)=7.2 Hz, 2H), 7.04 (t, 3J
3J
3J
3J
ACHTUNGTRENNUNG
3
ACHTUNGTRENNUNG(H,H)=7.2 Hz, 2H), 2.41 (s, 3H), 1.11 ppm (d, JACHTUGNTRENNNUG
E
ACHTUNGTRENNUNG
3
AHCTUNGTRENNUNG
G
A
ACHTUNGTRENNUNG
2.06 ppm (s, 6H); 13C{1H} NMR (150.9 MHz, CDCl3): d=162.7 (d,
A
R
ACHTUNGTRENNUNG
3J
19.8 Hz), 135.0 (d, J
2J(P,C)=9.6 Hz), 129.8, 129.5 (d, 3J
(d, 3J(P,C)=6.8 Hz), 128.4, 126.4, 123.9, 18.7 ppm; 31P{1H} NMR
(P,C)=2.6 Hz), 157.3 (d, 1J(P,C)=22.0 Hz), 151.6, 138.6 (d, 1J
AHCTUNGTREUNNGN ACHTUNGTRENNUNG ACHTUNGTRENNUNG
(P,C)=
(P,C)=9.2 Hz), 133.8 (d,
ACHTUNGTRENN(UNG P,C)=8.1 Hz), 129.04, 128.99, 128.8
A
ACHTUNGTRENNUNG
3
2
2
A
ACHTUNGTREN(NUGN H,H)=6.6 Hz, 12H);
ACHUTNGRENNU(G P,C)=20.4 Hz), 134.7 (d, JACTHUNGTRENNUNG
E
U
143.9, 137.5, 134.6, 129.8, 129.6, 128.7, 124.3, 123.2, 28.1, 23.7, 15.4 ppm;
Z isomer: d=162.6, 150.8, 149.6, 138.6, 137.6, 131.9, 129.4, 129.3, 128.6,
124.5, 123.3, 28.2, 23.9, 16.2 ppm; IR (KBr) n˜ =3058 (m), 3025 (m), 2958
(s), 2916 (s), 2886 (s), 2724 (w), 1948 (w), 1914 (w), 1806 (w), 1693 (w),
1614 (s), 1591 (s), 1514 (w), 1487 (m), 1460 (s), 1442 (s), 1379 (m), 1361
(m), 1320 (m), 1284 (m), 1266 (s), 1237 (m), 1184 (s), 1162 (w), 1098 (m),
1071 (m), 1022 (s), 967 (w), 927 (m), 900 (s), 845 (m), 796 (m), 759 (s),
714 (s), 701 (s), 674 (w), 624 cmÀ1 (m); HRMS: m/z calcd for C22H25NCl:
338.16755 [MÀH]+; found: 338.16765.
AHCTUNGTRENNUNG
(161.9 MHz, CDCl3): d=5.8 ppm; IR (KBr) n˜ =3062 (m), 2926 (s), 2852
(s), 1955 (w), 1887 (w), 1808 (w), 1767 (w), 1615 (m), 1584 (m), 1547 (w),
1458 (s), 1437 (m), 1379 (m), 1305 (w), 1259 (m), 1196 (m), 1133 (w),
1091 (m), 1023 (w), 924 (w), 887 (w), 835 (m), 772 (m), 735 (m), 693 (s),
625 (w), 599 cmÀ1 (m); HRMS: m/z calcd for C29H26NP: 419.1803 [M]+;
found: 419.1802.
3d: Red-orange solid (0.466 g, 69.4%); m.p. 91–938C; 1H NMR
(599.9 MHz, CDCl3) d=7.71 (d, 3J
ACHTUNGTRENNUNG
General synthesis of a,b-unsaturated-3-iminophosphines (3a–o)
4H), 7.36–7.39 (m, 6H), 7.32 (d, 3J
G
3J
3J
A
ACHTUNGTRENNUNG
Method A: Three Schlenk tubes were charged with bis(1,5-cyclooctadie-
ne)nickel(0) (0.075 mmol), the corresponding a,b-unsaturated b-chloro-
imine (1.50 mmol), and Ph2PSiMe3 (1.80 mmol) respectively. 5 mL of tol-
uene was added to each Schlenk tube. The contents of the Schlenk tubes
were combined and heated at reflux for 14 h. The solution was cooled to
room temperature and passed through a pad of Celite 545. The solvent
was removed to yield the crude product primarily, with only minimal cat-
alyst contamination. The solid was recrystallized from either pentane or
diethyl ether at À258C.
3
3
AHCTUNGTRENGU(NN H,H)=6.6 Hz, 2H), 6.95 (t, JACHTUNGTREG(NNUN H,H)=6.6 Hz, 1H), 6.39 (dd, JACHTUNGTRENNUNG
9.0 Hz, J
ACHTUNGTRENNUNG
3
3
(P,H)=4.8 Hz, 1H), 2.39 (q, J
R
3J
3J
C
G
ACHTUNGTRENNUNG
19.6 Hz), 135.0 (d, 2J
N
ACHTUNGTRENNUNG
129.8, 129.4 (d, 4J
3J
T
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
(161.9 MHz, CDCl3): d=5.9 ppm; IR (Nujol) n˜ =3052 (m), 2957 (s), 2915
(s), 2852 (s), 1950 (w), 1892 (w), 1876 (w), 1803 (w), 1615 (s), 1583 (m),
1458 (s), 1374 (m), 1306 (w), 1254 (w), 1186 (m), 1159 (w), 1133 (m),
1091 (m), 1070 (w), 1028 (w), 997 (w), 960 (w), 929 (w), 887 (w), 871 (w),
Method B: Two Schlenk tubes were charged with the corresponding a,b-
unsaturated b-chloroimine (1.50 mmol) and LiPPh2 (1.80 mmol), respec-
tively. Toluene (30 mL) was added to each Schlenk tube and cooled to
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2669

J. A. R. Schmidt and A. R. Shaffer
840 (w), 798 (w), 762 (m), 740 (m), 693 (s), 625 (w), 604 cmÀ1 (w);
3j: Yellow liquid (0.302 g, 44.2%); 1H NMR (599.9 MHz, CDCl3) d=
HRMS: m/z calcd for C31H30NP: 447.21158 [M]+; found: 447.21165.
7.59 (d, 3J
7.18 (t, 3J
(sept, 3J(H,H)=6.6 Hz, 2H), 1.43 (s, 9H), 0.92 ppm (d, 3J
12H); 13C{1H} NMR (150.9 MHz, CDCl3): d=162.8 (d, 3J
162.6 (d, 1J(P,C)=29.7 Hz), 153.0 (d, 1J
(P,C)=39.9 Hz), 148.7, 136.8,
(P,C)=15.0 Hz), 131.9 (d, 2J
(P,C)=18.2 Hz), 128.9 (d,
(P,C)=5.7 Hz), 128.8, 124.0, 122.6, 40.4 (d, 2J
(P,C)=30.0 Hz), 30.2 (d,
(P,C)=11.0 Hz), 27.5, 23.4 ppm; 31P{1H} NMR (161.9 MHz, CDCl3): d=
ACHTUNGTRENNUNG
3e: Yellow crystals (0.528 g, 74.0%); m.p. 134–1358C; 1H NMR
A
ACHTUNGTRENNUNG
(599.9 MHz, CDCl3) E isomer: d=7.68 (d, 3J
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
7.51 (m, 4H), 7.36–7.37 (m, 6H), 7.32 (d, 3J
3J(H,H)=7.2 Hz, 3H), 7.06 (d, 3J
7.8 Hz, 1H), 6.39 (dd, 3J
(H,H)=9.6 Hz, J
3J
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
A
ACHTUNGTRENNUNG
G
U
ACHTUNGTRENNUNG
136.5 (d, 2J
G
A
ACHTUNGTRENNUNG
3
A
ACHTUNGTRENNUNG
3J
3J
ACHTUNGTRENNUNG
E
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
À19.6 ppm; IR (KBr) n˜ =3054 (m), 2960 (s), 2866 (m), 1956 (w), 1883
(w), 1810 (w), 1627 (s), 1611 (s), 1585 (m), 1475 (s), 1459 (s), 1433 (s),
1386 (w), 1360 (m), 1323 (w), 1260 (m), 1181 (m), 1145 (w), 1098 (m),
1046 (m), 1020 (m), 920 (w), 889 (w), 836 (w), 800 (m), 742 (s), 721 (m),
695 (s), 643 (w), 596 (m), 569 (m), 506 cmÀ1 (s); HRMS: m/z calcd for
C31H38NP: 455.2742 [M]+; found: 455.2741.
A
G
ACHTUNGTRENNUNG
R
ACHTUNGTRENNUNG
G
E
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
31P{1H} NMR (161.9 MHz, CDCl3): d=4.6 ppm; IR (Nujol) n˜ =3061 (m),
2916 (s), 2854 (s), 1664 (w), 1612 (s), 1586 (m), 1457 (s), 1436 (m), 1379
(m), 1322 (m), 1259 (w), 1187 (m), 1130 (m), 1099 (m), 1020 (w), 1000
(w), 932 (w), 891 (m), 834 (m), 798 (m), 772 (w), 761 (m), 746 (m),
691 cmÀ1 (s); HRMS: m/z calcd for C33H34NP: 475.24288 [M]+; found:
475.24282.
3k: Red liquid (0.365 g, 63.1%); NMR (600 MHz) d=9.13 (d, 4J
ACHTUNGTRENNUNG(P,H)=
8.4 Hz, 1H), 7.15–7.20 (m, 10H), 6.83–6.91 (m, 3H), 6.63–6.66 (m, 2H),
1.91 (s, 3H), 1.14 ppm (s, 9H); 13C{1H} NMR (150.9 MHz, CDCl3): d=
3
157.3 (d, J
G
E
E
19.8 Hz), 144.5 (d, 1J
(d, 2J(P,C)=25.0 Hz), 129.3, 128.8 (d, 2J
4J(P,C)=3.0 Hz), 128.3 (d, 3J
(d, 3J
(P,C)=26.4 Hz), 136.4 (d, 3J
ACHUTGTNRENNUG CAHTUNGTRENNUNG
3 f: White solid (0.299 g, 56.7%); m.p. 94–968C; 1H NMR (599.9 MHz,
CDCl3) d=7.59 (d, 3J(H,H)=9.0 Hz, 1H), 7.36 (pseudo t, 3J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
A
7.8 Hz, 4H), 7.30 (t, 3J
N
2H), 6.88 (t, 3J(H,H)=9.0 Hz, 3J
U
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
IR (KBr) n˜ =3135 (w), 3051 (m), 3009 (w), 2968 (s), 2915 (m), 2863 (w),
1950 (w), 1887 (w), 1808 (w), 1761 (w), 1615 (s), 1589 (w), 1479 (m), 1432
(s), 1361 (m), 1306 (w), 1259 (m), 1217 (m), 1154 (w), 1091 (w), 1070 (w),
1023 (s), 955 (w), 929 (w), 913 (w), 892 (w), 845 (w), 798 (m), 777 (w),
740 (s), 699 (s), 641 (w), 615 cmÀ1 (w); HRMS: m/z calcd for C26H28NP:
385.1959 [M]+; found: 385.1956.
G
G
ACHTUNGTRENNUNG
E
G
ACHTUNGTRENNUNG
N
ACHTUNGTRENNUNG
29.5 ppm; 31P{1H} NMR (161.9 MHz, CDCl3): d=À20.1 ppm; IR (Nujol)
n˜ =3124 (w), 3072 (m), 3049 (m), 2958 (s), 2901 (s), 2843 (s), 2667 (w),
1958 (w), 1950 (w), 1887 (w), 1864 (w), 1809 (w), 1768 (w), 1742 (w),
1714 (w), 1664 (w), 1652 (w), 1620 (m), 1579 (m), 1542 (w), 1462 (s),
1434 (s), 1376 (m), 1361 (m), 1319 (w), 1296 (w), 1265 (w), 1229 (w),
1216 (m), 1182 (m), 1145 (w), 1109 (w), 1088 (w), 1062 (w), 1020 (w), 995
(w), 953 (w), 930 (w), 885 (w), 844 (w), 798 (w), 775 (w), 741 (s), 720
(m), 689 (s), 642 (m), 595 (s), 507 cmÀ1 (s); HRMS: m/z calcd for
C23H30NP: 351.2116 [M]+; found: 351.2112.
3l: Yellow solid (0.319 g, 52.4%); m.p. 152–1548C; 1H NMR
(599.9 MHz, CDCl3) d=9.45 (d, 4J
ACTHNUTRGNE(NUG P,H)=8.4 Hz, 1H), 7.32–7.34 (m,
2H), 7.23–7.25 (m, 5H), 7.18–7.22 (m, 6H), 7.06–7.08 (m, 2H), 6.98–7.01
(m, 3H), 6.60–6.61 (m, 2H), 2.06 ppm (s, 3H); 13C{1H} NMR (150.9 MHz,
CDCl3): d=161.4 (d, 1J
G
G
2
4
32.4 Hz), 146.7 (d, J
(P,C)=20.0 Hz), 140.2 (d, J
2J
3J
(P,C)=10.0 Hz), 133.8 (d, 2J
ACHUTGTNRENNUG CAHTUNGTRENNUNG
1
C
3h: Yellow liquid (0.401 g, 66.9%); b.p. >1708C (0.10 mmHg); H NMR
4.0 Hz); 31P{1H} NMR (161.9 MHz, CDCl3): d=À6.0 ppm; IR (Nujol) n˜ =
2948 (s), 2910 (s), 2858 (s), 2722 (w), 2669 (w), 1602 (w), 1576 (m), 1460
(s), 1371 (s), 1309 (w), 1262 (w), 1193 (w), 1152 (w), 1094 (w), 1069 (w),
1021 (m), 968 (w), 921 (w), 879 (w), 843 (w), 801 (w), 764 (m), 738 (m),
717 (m), 691 (m), 633 (m), 610 cmÀ1 (s); HRMS: m/z calcd for C28H24NP:
405.1646 [M]+; found: 405.1643.
(599.9 MHz, CDCl3) d=7.54 (d, 3J
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
3
1
1
(d, J
15.9 Hz), 136.3 (d, J
3J(P,C)=5.6 Hz), 128.3, 127.7, 126.4, 123.4, 40.2 (d, 2J
30.1 (d, 3J(P,C)=11.1 Hz), 18.1 ppm; 31P{1H} NMR (161.9 MHz, CDCl3):
2
2
N
G
3m: Yellow liquid (0.310 g, 47.7%); 1H NMR (599.9 MHz, CDCl3) d=
E
9.19 (d, 4J(P,H)=8.4 Hz, 1H), 7.17–7.23 (m, 11H), 7.02 (d, 3J
AHTCUNGTRENNUGN ACHTUNGTRENNUNG
d=À20.9 ppm; IR (KBr) n˜ =3136 (w), 3053 (m), 3021 (m), 2958 (s), 2906
(s), 2836 (s), 2728 (w), 2581 (w), 2026 (w), 1950 (w), 1882 (w), 1809 (w),
1772 (w), 1615 (s), 1579 (s), 1469 (s), 1432 (s), 1385 (m), 1354 (m), 1301
(w), 1259 (m), 1238 (w), 1191 (s), 1150 (m), 1087 (s), 1024 (m), 998 (m),
951 (w), 919 (w), 888 (m), 835 (m), 794 (m), 762 (s), 741 (s), 694 (s), 676
(m), 600 (s), 587 cmÀ1 (m); HRMS: m/z calcd for C27H30NP: 399.2116
[M]+; found: 399.2114.
7.8 Hz, 2H), 6.94–6.97 (m, 2H), 6.91 (t, 3J
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
E
ACHTUNGTRENNUNG
3
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
3i: Yellow liquid (0.260 g, 40.5%); 1H NMR (599.9 MHz, CDCl3) d=
À6.0 ppm; IR (KBr) n˜ =3042 (m), 2926 (s), 2853 (s), 2727 (w), 2674 (w),
1950 (w), 1892 (w), 1808 (w), 1767 (w), 1615 (s), 1589 (m), 1463 (s), 1432
(s), 1374 (m), 1264 (s), 1191 (m), 1091 (s), 1070 (m), 1019 (s), 929 (w),
887 (w), 845 (w), 803 (m), 735 (s), 699 (m), 641 cmÀ1 (m); HRMS: m/z
calcd for C30H28NP: 433.1959 [M]+; found: 433.1958.
7.59 (d, 3J
7.15 (t, 3J
(q, 3J(H,H)=7.8 Hz, 4H), 1.43 (s, 9H), 0.91 ppm (t, 3J
6H); 13C{1H} NMR (150.9 MHz, CDCl3): d=163.7 (d, 3J
150.2, 136.6 (d, 2J(P,C)=21.4 Hz), 134.2 (d, 1J
(P,C)=16.5 Hz), 132.3,
(P,C)=18.2 Hz), 129.2 (d, 1J
(P,C)=11.8 Hz), 128.9 (d,
(P,C)=5.7 Hz), 128.3, 125.5, 123.8, 40.3 (d, 2J
(P,C)=30.6 Hz), 30.1 (d,
(P,C)=11.1 Hz), 24.2, 14.2 ppm; 31P{1H} NMR (161.9 MHz, CDCl3): d=
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
A
R
3n: Yellow solid (0.404 g, 58.3%); m.p. 108–1098C; 1H NMR
131.9 (d, 2J
G
G
E
(599.9 MHz, CDCl3) d=9.21 (d, 4J
ACHTUNGTRENNUNG
3J
3J
E
11H), 7.04 (d, 3J
N
ACHTUNGTRENNUNG
C
ACHTUNGTRENNUNG
À20.4 ppm; IR (KBr) n˜ =3056 (m), 3002 (w), 2961 (s), 2919 (m), 2887
(m), 1922 (w), 1884 (w), 1811 (w), 1612 (s), 1586 (m), 1476 (m), 1450
(m), 1421 (m), 1387 (w), 1356 (w), 1329 (w), 1303 (w), 1256 (w), 1235
(w), 1209 (w), 1183 (m), 1146 (w), 1099 (m), 1061 (w), 1026 (m), 1000
(w), 947 (w), 890 (w), 863 (w), 842 (w), 800 (m), 758 (m), 743 (s), 696 (s),
638 (w), 602 (m), 507 (m), 476 cmÀ1 (m); HRMS: m/z calcd for
C29H34NP: 427.2429 [M]+; found: 427.2433.
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
E
ACHTUNGTRENNUNG
G
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
2670
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

Iminophosphine Synthesis
FULL PAPER
1956 (w), 1888 (w), 1809 (w), 1762 (w), 1678 (w), 1616 (m), 1584 (m),
1458 (s), 1432 (m), 1375 (m), 1307 (w), 1260 (m), 1223 (w), 1181 (m),
1155 (w), 1092 (m), 1076 (m), 1024 (m), 966 (w), 919 (w), 883 (w), 862
(w), 840 (w), 799 (m), 768 (m), 737 (s), 720 (m), 694 (s), 637 (w), 516 (s),
480 cmÀ1 (s); HRMS: m/z calcd for C32H32NP: 461.2272 for [M]+; found:
461.2279.
127.2, 125.5, 123.5, 24.5, 13.6 ppm; 31P{1H} NMR (161.9 MHz, CDCl3):
d=24.7 ppm; IR (Nujol) n˜ =3053 (m), 2948 (s), 2917 (s), 2854 (s), 1636
(w), 1600 (m), 1579 (m), 1542 (w), 1458 (s), 1375 (m), 1338 (w), 1301 (w),
1260 (w), 1232 (w), 1186 (w), 1155 (w), 1092 (m), 1029 (w), 888 (w), 846
(w), 804 (w), 768 (w), 736 (m), 715 cmÀ1 (w); elemental analysis calcd
(%) for C55H50ClNP2Pd·CH2Cl2: C 66.34, H 5.18, N 1.38; found: C 66.27,
H 4.76, N 1.30.
3o: Yellow solid (0.524 g, 71.3%); m.p. 123–1248C; 1H NMR
(599.9 MHz, CDCl3) d=9.23 (d, 4J
ACHTUNGTRENNUNG
7: A solution of 2b (0.682 g, 1.74 mmol) in CH2Cl2 (15 mL) was added to
a stirred solution of (allyl)palladiumchloride dimer (0.318 g, 0.871 mmol)
in CH2Cl2 (15 mL) and stirred for 14 h. The solvent was evaporated,
yielding a yellow-orange solid, which was dissolved in THF and precipi-
tated using pentane at À258C to yield 7 (0.824 g, 82.4%). Orange crystals
were grown from a layered solution of THF and pentane at ambient tem-
perature. M.p. 99–1018C; 1H NMR (599.9 MHz, CDCl3) d=8.01 (d,
10H), 7.05 (d, 3J
N
ACHTUNGTRENNUNG
3
3J
G
ACHTUNGTREN(NUGN H,H)=7.2 Hz, 12H);
13C{1H} NMR (150.9 MHz, CDCl3): d=163.3 (d, 1J
AHCTUNGTRENNUNG
3
1
2
(d, J
21.0 Hz), 134.2 (d, 2J
128.8, 128.6, 128.3 (d, 3J
23.0, 17.5 ppm (d, 3J(P,C)=4.8 Hz); 31P{1H} NMR (161.9 MHz, CDCl3):
G
G
ACHTUNGTRNE(NUNG P,C)=
G
ACHTUNGTRENNUNG
3J
3J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
A
E
ACHTUNGTRENNUNG
7.8 Hz, 3H), 7.17 (t, 3J
R
ACHTUNGTRENNUNG
d=À6.2 ppm; IR (Nujol) n˜ =3047 (w), 2955 (s), 2918 (s), 2845 (s), 2726
(w), 2671 (w), 1612 (w), 1584 (w), 1456 (m), 1374 (m), 1305 (w), 1259
(w), 1222 (w), 1181 (w), 1094 (w), 1071 (w), 1021 (w), 925 (w), 884 (w),
796 (w), 764 (w), 742 (w), 696 cmÀ1 (m); HRMS: m/z calcd for C34H36NP:
489.2585 [M]+; found: 489.2582.
2H), 6.88 (dd, 3J
3J
G
ACHTUNGTRENNUNG
E
U
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
3
4: Yellow solid, decomposition product of 2g (0.585 g, 61.9%); m.p. 151–
1548C; 1H NMR (599.9 MHz, CDCl3) d=9.87 (brs, 1H), 7.46 (pseudo t,
AHCTUNGTRENNUNG
148.4 (d, 1J
G
G
ACHTUNGTRENNUNG
3J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG ACTUHNGTRENNNGU
(H,H)=7.8 Hz, 3J(H,H)=7.2 Hz, 2H), 7.38 (t, 3J
2J
1J
ACHTUNGTRENNUNG
3
3
7.34 (d, JACHTUNGTRENNUNG(H,H)=7.8 Hz, 2H), 7.14 (pseudo t, JACHTUGNTRENNNUG
7.07 (t, JACHTUNGTRENNUNG(H,H)=7.2 Hz, 1H), 6.70 (d, JACHTUNGTRENNUNG
N
G
ACHTUNGTRENNUNG
3
3
2.2 Hz), 128.8 (d, 4J
N
ACHTUNGTRENNUNG
5.2 Hz), 80.0 (d, 2J
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
(150.9 MHz, CDCl3): d=181.4, 152.9, 146.9, 138.8, 131.2, 129.7, 128.7,
126.4, 126.0, 117.9, 91.9, 40.0, 29.7 ppm; IR (Nujol) n˜ =3443 (w), 3370
(w), 3192 (w), 3087 (w), 2951 (s), 2919 (s), 2846 (s), 1633 (s), 1591 (m),
1523 (s), 1481 (s), 1465 (s), 1360 (m), 1324 (m), 1282 (s), 1256 (m), 1214
(m), 1172 (w), 1093 (m), 1078 (w), 1025 (w), 995 (m), 968 (m), 931 (w),
905 (w), 863 (w), 811 (m), 758 (m), 722 (w), 696 cmÀ1 (m); HRMS: m/z
calcd for C19H22N2: 278.1783 [MÀHCl]+; found: 278.1783.
CDCl3): d=32.3 ppm; IR (Nujol) n˜ =3045 (m), 2953 (s), 2916 (s), 2852
(s), 2724 (w), 2669 (w), 1597 (w), 1579 (w), 1460 (m), 1437 (m), 1373 (m),
1308 (w), 1263 (w), 1189 (w), 1157 (w), 1134 (w), 1093 (m), 1066 (w),
1020 (w), 956 (w), 933 (w), 896 (w), 837 (w), 795 (w), 768 (m), 750 (w),
715 (w), 695 (m), 598 cmÀ1 (m); elemental analysis calcd (%) for
C30H27ClNPPd: C 62.73, H 4.74, N 2.44; found: C 62.40, H 4.84, N 2.18.
Crystallography: A summary of crystal data and collection parameters
for crystal structures of 3 f, 5, and 7 are provided in Table 4. Detailed de-
5: A solution of 2d (0.385 g, 1.29 mmol) in toluene (15 mL) was added to
a stirred solution of tetrakis(triphenyl-
phosphine)palladium(0)
(1.245 g,
1.077 mmol) in toluene (15 mL) at
08C. The reaction was warmed to am-
bient temperature and stirred for an
additional 14 h. The solvent was
Table 4. Crystal data and collection parameters.
Compound
3f
5
7
formula
Mr
C23H30NP
351.51
C55H50ClNP2Pd·0.6 C5H12
972.17
P21/c (#14)
140
18.314(1)
10.929(1)
24.314(1)
90.000
99.009(1)
90.000
4807.0(1)
4
1.303
Siemens SMART
MoKa (l=0.71069 ꢁ)
graphite
CCD area detector
w, 0.38
C30H27ClNPPd
574.42
P1 (#2)
140
9.923(1)
12.152(1)
12.453(1)
108.390(2)
104.282(2)
104.625(2)
1288.8(2)
2
evaporated, yielding
a yellow solid,
¯
space group
T [K]
a [ꢁ]
b [ꢁ]
c [ꢁ]
P21/c (#14)
150
12.993(6)
15.179(8)
11.373(6)
90.000
which was triturated with pentane (3ꢂ
5 mL) and then washed with pentane
(3ꢂ25 mL) to remove free triphenyl-
phosphine. The solid was dissolved in
toluene and precipitated using pentane
at À258C to yield 5 (0.923 g, 92.3%).
Yellow crystals were grown from a lay-
ered solution of CH2Cl2 and diethyl
ether at ambient temperature. M.p.
227–2288C; 1H NMR (599.9 MHz,
a [8]
b [8]
109.31(1)
90.000
2116.7(2)
4
g [8]
V [ꢁ3]
Z
1calcd [gcmÀ3
]
1.103
1.480
CDCl3) d=8.90 (d, 3J
ACHTUNGTRENNUNG(H,H)=9.0 Hz,
diffractometer
radiation
monochromator
detector
scan type, width
scan speed
no. of reflns measd
2q range [8]
Siemens SMART
MoKa (l=0.71069 ꢁ)
graphite
CCD area detector
w, 0.38
30.0 s/frame
hemisphere
4.9-55.3
Siemens SMART
MoKa (l=0.71069 ꢁ)
graphite
CCD area detector
w, 0.38
15.0 s/frame
hemisphere
4.5-56.6
1H), 7.51–7.59 (m, 12H), 7.29–7.35
(m, 8H), 7.20–7.23 (m, 12H), 6.98–
7.03 (m, 3H), 6.92–6.95 (m, 1H), 6.79–
6.82 (m, 2H), 6.46 (d, 3J
ACHTUNGTRENNUNG
9.0 Hz, 1H), 1.88 (q, 3J
4H), 0.89 ppm (t, 3J
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
30.0 s/frame
hemisphere
4.5-67.8
6H);
13C{1H} NMR
crystal size [mm]
no. of reflns measd
no. of unique reflns
no. of observations
no. of parameters
R, Rw, Rall
0.20ꢂ0.16ꢂ0.16
23789
5349
5349
226
0.45ꢂ0.26ꢂ0.06
61781
20542
20542
552
0.30ꢂ0.30ꢂ0.20
15217
6421
6421
307
G
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
ACHTUNGTRENNUNG
R
ACHTUNGTRENNUNG
0.0494, 0.1448, 0.0777
0.967
0.0501, 0.1146, 0.0714
1.068
0.0316, 0.0795, 0.0577
1.047
ACHTUNGTRENNUNG
GOF
ACHTUNGTRENNUNG
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2671

J. A. R. Schmidt and A. R. Shaffer
scriptions of data collection, as well as data solution, are provided below.
ORTEP diagrams were generated with the ORTEP-3[49] software pack-
age. For each sample, a suitable crystal was mounted on a pulled glass
fiber using Paratone-N hydrocarbon oil. The crystal was transferred to a
Siemens SMART[50] diffractometer with a CCD area detector, centered
in the X-ray beam, and cooled to 140 or 150 K using a nitrogen-flow low-
temperature apparatus that had been previously calibrated by a thermo-
couple placed at the same position as the crystal. An arbitrary hemi-
sphere of data was collected using 0.38 w scans, and the data were inte-
grated by the program SAINT.[51] The final unit cell parameters were de-
termined by a least-squares refinement of the reflections with I>10s(I).
Data analysis using Siemens XPREP[52] and the successful solution and
refinement of the structure determined the space group. Empirical ab-
[12] J. P. Wolfe, S. Wagaw, J. F. Marcoux, S. L. Buchwald, Acc. Chem.
Res. 1998, 31, 805–818.
[13] L. Penn, A. Shpruhman, D. Gelman, J. Org. Chem. 2007, 72, 3875–
3879.
[14] A. Scrivanti, M. Bertoldini, U. Matteoli, V. Beghetto, S. Antonaroli,
A. Marini, B. Crociani, J. Mol. Catal. A 2005, 235, 12–16.
[15] M. Koprowski, R. M. Sebastian, V. Maraval, M. Zablocka, V.
Cadierno, B. Donnadieu, A. Igau, A. M. Caminade, J. P. Majoral,
Organometallics 2002, 21, 4680–4687.
[16] Phosphorus Ligands in Asymmetric Catalysis: Synthesis and Appli-
cations, Vol. 1–3 (Ed.: A. Bçrner), Wiley-VCH, Weinheim, 2008.
[17] D. S. Glueck, Chem. Eur. J. 2008, 14, 7108–7117.
[18] B. H. Lipshutz, A. Lower, R. J. Kucejko, K. Noson, Org. Lett. 2006,
8, 2969–2972.
[19] C. S. Slone, D. A. Weinberger, C. A. Mirkin, Prog. Inorg. Chem.
1999, 48, 233–350.
[20] I. D. Kostas, Curr. Org. Synth. 2008, 5, 227–249.
[21] K. Hiroi, K. Watanabe, Tetrahedron: Asymmetry 2002, 13, 1841–
1843.
sorption corrections were applied for
5 and 7 using the program
SADABS.[53] Equivalent reflections were averaged, and the structures
were solved by direct methods using the SHELXTL software package.[54]
Unless otherwise noted, all non-hydrogen atoms were refined anisotropi-
cally, and hydrogen atoms were included as fixed atoms but not refined.
Compound 3 f: X-ray quality crystals were grown from a saturated solu-
tion in pentane at À258C. The final cycle of full-matrix least-squares re-
finement was based on 5349 observed reflections and 226 variable param-
eters and converged yielding final residuals: R=0.0494, Rall =0.0777, and
GOF=0.967.
[22] S. L. Yao, S. Saaby, R. G. Hazell, K. A. Jorgensen, Chem. Eur. J.
2000, 6, 2435–2448.
[23] A. R. Shaffer, J. A. R. Schmidt, Organometallics 2008, 27, 1259–
1266.
[24] C. P. Casey, G. A. Bikzhanova, I. A. Guzei, J. Am. Chem. Soc. 2006,
128, 2286–2293.
[25] P. Spies, S. Schwendemann, S. Lange, G. Kehr, R. Frohlich, G.
Erker, Angew. Chem. 2008, 120, 7654–7657; Angew. Chem. Int. Ed.
2008, 47, 7543–7546.
Compound 5: X-ray quality crystals were grown from a layered solution
of toluene and pentane at room temperature. One molecule of disor-
dered pentane existed in the asymmetric unit and was refined isotropical-
ly. Hydrogen atoms were included for all ordered atoms. The final cycle
of full-matrix least-squares refinement was based on 20542 observed re-
flections and 552 variable parameters and converged yielding final resid-
uals: R=0.0501, Rall =0.0713, and GOF=1.068.
[26] S. E. Denmark, N. Nakajima, C. M. Stiff, O. J. C. Nicaise, M. Kranz,
Adv. Synth. Catal. 2008, 350, 1023–1045.
[27] G. K. Friestad, A. K. Mathies, Tetrahedron 2007, 63, 2541–2569.
[28] T. Vilaivan, W. Bhanthumnavin, Y. Sritana-Anant, Curr. Org. Chem.
2005, 9, 1315–1392.
[29] S. Kobayashi, H. Ishitani, Chem. Rev. 1999, 99, 1069–1094.
[30] R. Bloch, Chem. Rev. 1998, 98, 1407–1438.
Compound 7: X-ray quality crystals were grown from a layered solution
of THF and pentane at room temperature. The final cycle of full-matrix
least-squares refinement was based on 6421 observed reflections and 307
variable parameters and converged yielding final residuals: R=0.0316,
R
all =0.0577, and GOF=1.047.
[31] E. V. Vashkevich, V. I. Potkin, N. G. Kozov, E. D. Skakovskii, Russ.
J. Org. Chem. 2003, 39, 1587–1592.
CCDC-708151, 708152, 708153, 708154, 708155, 708156, 708157, 708158,
708159, and 708160 contain the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_
request/cif.
[32] A. Chakraborty, J. K. Ray, Synth. Commun. 1995, 25, 1869–1876.
[33] R. T. Lalonde, R. A. Florence, B. A. Horenstein, R. C. Fritz, L.
Silveira, J. Clardy, B. S. Krishnan, J. Org. Chem. 1985, 50, 85–91.
[34] P. Cagniant, G. Kirsch, C. R. Acad. Sci. Ser. IIc 1975, 281, 35–38.
[35] Z. Arnold, J. Zemlicka, Collect. Czech. Chem. Commun. 1959, 55,
2385–2392.
[36] A 1H NMR spectrum is included in the Supporting Information as
confirmation of our proton resonance assignments.
[37] W. T. Brady, C. H. Shieh, J. Org. Chem. 1983, 48, 2499–2502.
[38] M. Beit-Yannai, Z. Rappoport, J. Org. Chem. 1997, 62, 5634–5637.
[39] J. Scholz, S. Kahlert, H. Gorls, Organometallics 2004, 23, 1594–1603.
[40] M. A. Kazankova, E. A. Chirkov, A. N. Kochetkov, I. V. Efimova,
I. P. Beletskaya, Tetrahedron Lett. 1999, 40, 573–576.
[41] M. O. Shulyupin, E. A. Chirkov, M. A. Kazankova, L. P. Beletskaya,
Synlett 2005, 658–660.
Acknowledgements
This material is based upon work supported by the National Science
Foundation under CHE-0841611. Additionally, we gratefully acknowl-
edge the University of Toledo for generous startup funding, as well as a
University of Toledo Interdisciplinary Research Initiation Award.
[42] G. D. Vaughn, K. A. Krein, J. A. Gladysz, Organometallics 1986, 5,
936–942.
[1] The Chemistry of Organophosphorus Compounds, Vol. 1 (Ed.: F. R.
Hartley), Wiley, New York, 1990.
[43] R. Y. Lai, K. Surekha, A. Hayashi, F. Ozawa, Y. H. Liu, S. M. Peng,
S. T. Liu, Organometallics 2007, 26, 1062–1068.
[44] C. Garcꢃa-Yebra, J. P. Janssen, F. Rominger, G. Helmchen, Organo-
metallics 2004, 23, 5459–5470.
[45] D. J. Krysan, P. B. Mackenzie, J. Org. Chem. 1990, 55, 4229–4230.
[46] S. D. Ittel, Inorg. Synth. 1990, 28, 98–104.
[2] J. Tsuji, Palladium Reagents and Catalysts, Wiley, New York, 2004.
[3] M. Beller, J. Seayad, A. Tillack, H. Jiao, Angew. Chem. 2004, 116,
3448–3479; Angew. Chem. Int. Ed. 2004, 43, 3368–3398.
[4] T. Minami, H. Okamoto, S. Ikeda, R. Tanaka, F. Ozawa, M. Yoshifu-
ji, Angew. Chem. 2001, 113, 4633–4635; Angew. Chem. Int. Ed.
2001, 40, 4501–4503.
[47] R. B. King, J. Bakos, C. D. Hoff, L. Marko, J. Org. Chem. 1979, 44,
1729–1731.
[5] J. R. Zhou, J. F. Hartwig, J. Am. Chem. Soc. 2008, 130, 12220–12221.
[6] K. Makino, M. Iwasaki, Y. Hamada, Org. Lett. 2006, 8, 4573–4576.
[7] A. Lightfoot, P. Schnider, A. Pfaltz, Angew. Chem. 1998, 110, 3047–
3050; Angew. Chem. Int. Ed. 1998, 37, 2897–2899.
[8] J. W. Faller, J. C. Wilt, Organometallics 2005, 24, 5076–5083.
[9] J. W. Faller, J. C. Wilt, Org. Lett. 2005, 7, 633–636.
[10] Y. Imada, M. Nishida, K. Kutsuwa, S. I. Murahashi, T. Naota, Org.
Lett. 2005, 7, 5837–5839.
[11] R. Stohler, F. Wahl, A. Pfaltz, Synthesis 2005, 1431–1436.
[48] K. M. Zhu, P. D. Achord, X. W. Zhang, K. Krogh-Jespersen, A. S.
Goldman, J. Am. Chem. Soc. 2004, 126, 13044–13053.
[49] L. J. Farrugia, J. Appl. Crystallogr. 1997, 30, 565.
[50] SMART, Area-Detector Software Package, v5.625, Bruker AXS,
Madison (USA), 1997–2001.
[51] SAINT, SAX Area-Detector Integration Program, V6.22, Bruker
AXS, Madison (USA), 1997–2001.
2672
www.chemeurj.org
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2009, 15, 2662 – 2673

Iminophosphine Synthesis
FULL PAPER
[52] XPREP, Reciprocal Space Exploration Program, V6.12, Bruker
AXS, Madison (USA), 2001.
[54] SHELXL-97, Structure Solution Program, V6.10, Bruker AXS,
Madison (USA), 2000.
[53] SADABS, Bruker/Siemens Area Detector Absorption Program,
V2.03; Bruker AXS, Madison (USA), 2001.
Received: November 6, 2008
Published online: January 29, 2009
Chem. Eur. J. 2009, 15, 2662 – 2673
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
2673