N-Acetyl-N,N-dipyrid-2-yl (cyclooctadiene) rhodium (I) and iridium (I) complexes: Synthesis, X-ray structures, their use in hydroformylation and carbonyl hydrosilylation reactions and in the polymerization of diazocompounds

Article abstract of DOI:10.1016/j.jorganchem.2007.08.009

The synthesis of novel N-acetyl-N,N-dipyrid-2-yl complexes of Rh^I and Ir^I, i.e. [RhCl(CH₃CONPy₂)(COD)] (1) and [IrCl(CH₃CONPy₂)(COD)] (2), respectively, is described. Upon prolonged treatment in CH₂Cl₂ at room temperature, complex 1 is transformed into a cationic Rh-complex, i.e. [Rh(CH₃CONPy₂)(COD)⁺RhCl₂(COD)^-] (1a). Compound 1a crystallizes in the monoclinic space group P2₁/c, complex 2 crystallizes in the triclinic space group P over(1, ?). Compound 1 was investigated for its catalytic activity in the hydroformylation of cyclooctene as well as of 1-octene. In addition, 1 was used in various carbonyl hydrosilylation reactions of both aldehydes and ketones. There, turn-over numbers up to 50 000 and yields in the range of 85-100% were observed. Finally, compound 1 was successfully used for the polymerization of N₂CHCOOEt yielding highly stereoregular poly(ethoxycarbonylcarbene) with M_w = 67 000 g/mol and a polydispersity index (PDI) of 2.59.

Full text of DOI:10.1016/j.jorganchem.2007.08.009

Journal of Organometallic Chemistry 692 (2007) 5272–5278
www.elsevier.com/locate/jorganchem
N-Acetyl-N,N-dipyrid-2-yl (cyclooctadiene) rhodium (I) and iridium
I) complexes: Synthesis, X-ray structures, their use
(
in hydroformylation and carbonyl hydrosilylation reactions and
in the polymerization of diazocompounds
a
b
a,c,
*
Bhasker Bantu , Klaus Wurst , Michael R. Buchmeiser
a
Leibniz-Institut f u¨ r Oberfl a¨ chenmodifizierung e.V. (IOM), Permoserstraße 15, D-04318 Leipzig, Germany
Institut f u¨ r Allgemeine, Anorganische und Theoretische Chemie, Universit a¨ t Innsbruck, Innrain 52a, A-6020 Innsbruck, Austria
b
c
Institut f u¨ r Technische Chemie, Universit a¨ t Leipzig, Linn e´ str. 3, D-04103 Leipzig, Germany
Received 30 April 2007; received in revised form 6 August 2007; accepted 9 August 2007
Available online 16 August 2007
Abstract
The synthesis of novel N-acetyl-N,N-dipyrid-2-yl complexes of Rh and Ir , i.e. [RhCl(CH CONPy )(COD)] (1) and [IrCl(CH CON-
I
I
3
2
3
Py
2
)(COD)] (2), respectively, is described. Upon prolonged treatment in CH
2
Cl
2
at roomtemperature, complex 1 is transformed into a cationic
/c, complex 2
+
ꢀ
Rh-complex, i.e. [Rh(CH
3
CONPy
2
)(COD) RhCl
2
(COD) ] (1a). Compound 1a crystallizes in the monoclinic space group P2
1
ꢀ
crystallizes in the triclinic space groupP1. Compound 1 was investigated for its catalytic activity in the hydroformylation of cyclooctene as well
as of 1-octene. In addition, 1 was used in various carbonyl hydrosilylation reactions of both aldehydes and ketones. There, turn-over numbers
up to 50000 and yields in the range of 85–100% were observed. Finally, compound 1 was successfully used for the polymerization of
N CHCOOEt yielding highly stereoregular poly(ethoxycarbonylcarbene) with M = 67000 g/mol and a polydispersity index (PDI) of 2.59.
2
w
Ó 2007 Elsevier B.V. All rights reserved.
Keywords: Rhodium; Iridium; Hydroformylation; Carbonyl hydrosilylation; Polymerization; Diazo compounds
1
. Introduction
the highly effective coupling of aryl iodides, arylbromides
as well as activated aryl chlorides. Due to the high affinity
of the ligand versus Pd, metal bleeding was low, allowing
for the multiple use of particularly supported systems [1].
Later, non-acylated versions of dipyrid-2-ylamine were
used by other groups [5–7]. In extension to our work, we
In contrast to their P-analogues, N-based ligands are
usually less strong electron donating ligands, however, pos-
sess the great advantage of being entirely stable towards
oxygen even at higher temperatures. Some time ago, we
reported on various dipyridylamide ligands, the corre-
sponding Pd complexes, their immobilization on both
organic and inorganic supports and their use in C–C
coupling reactions such as Heck-, Suzuki and Sono-
gashira-Hagihara-type reactions [1–4]. Particularly Pd(II)
complexes of N-acyl-N,N-dipyrid-2-yl amine allowed for
I
report here on the synthesis of the corresponding Rh
I
and Ir complexes of N,N-dipyrid-2-ylacetamide and their
use in various catalytic reactions.
2. Results and discussion
2.1. Synthesis of Rh- and Ir-complexes of N,N-dipyrid-2-
ylacetamide
*
Corresponding author. Address: Leibniz-Institut f u¨ r Oberfl a¨ chenmod-
ifizierung e.V. (IOM), Permoserstraße 15, D-04318 Leipzig, Germany.
Tel.: +49 (0) 341 235 2229; fax: +49 (0) 341 235 2584.
E-mail address: michael.buchmeiser@iom-leipzig.de (M.R. Buchmei-
ser).
Compound 1 was synthesized from [RhCl(COD)] and
2
N,N-dipyrid-2-ylacetamide in 95% yield (Scheme 1). Inter-
0
022-328X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.08.009

B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
5273
Scheme 1. Synthesis of compounds 1, 1a and 2.
estingly, prolonged treatment with methylene chloride gave
raise to a further transformation that resulted in the forma-
ingly, the distances Ir–N(2) and Ir–N(3) were comparable
to those found in 1a, i.e. 212.6(6) and 213.4(6) pm, respec-
tively. The same accounts for the angle N(2)–Ir(1)–N(3),
which was 83.7(2)°. This is remarkable, since the larger
atom diameter of Ir would let expect both longer bonds
and a larger angle. Since the Rh-complexes are in general
more reactive than the corresponding Ir-analogues, com-
plex 1 was used for all further investigations.
+
tion of a cationic complex [Rh(CH CONPy ) RhCl -
3
2
2
ꢀ
(
COD) ] (1a). Compound 1a crystallizes in the monoclinic
space group P2 / c (No. 14) with a = 1069.22(2) pm,
1
b = 1268.89(2) pm, c = 2260.67(3) pm, a = c = 90°, b =
9
5.928(1)°, Z = 4 (Fig. 1a). Selected bond distances are
also summarized in Fig. 1a. As can be deduced therefrom,
the Rh(1)–N(1) and Rh(1)–N(2) distances were basically
identical, i.e. 213.01(2) and 213.03(2) pm, the angle N(1)–
Rh(1)–N(2) was 83.58(7)°.
2.2. Hydroformylation reactions
Compound 2 was prepared in a similar manner from
Hydroformylation reactions are among the most impor-
tant industrial processes with a world wide production of
several million tons. Starting from readily available
alkenes, dihydrogen and carbon monoxide, highly valuable
n-aldehydes as well as the corresponding regioisomers are
available [8–12]. Numerous transition metals such as Rh,
Pt, Co and Ru may be used for these purposes, however,
[
IrCl(COD)] and N,N-dipyrid-2-ylacetamide in 90% yield
2
(
Scheme 1). Compound 2 crystallizes in the triclinic space
ꢀ
group P1 (No. 2) with a = 1113.34(5) pm, b =
1
9
304.17(7) pm, c = 1430.73(6) pm, a = 96.321(2)°, b =
2.704(3)° and c = 105.319(2)°, Z = 4 (Fig. 1b). Selected
bond distances are also summarized in Fig. 1b. Surpris-
Fig. 1. X-ray structures of 1a (left) Rh(1)–C(5) 210.1(2) pm, Rh(1)–C(6) 211.5(2) pm, Rh(1)–C(1) 212.5(2) pm, Rh(1)–N(2) 213.01(2) pm, Rh(1)–N(1)
13.05(2) pm, Rh(1)–C(2) 213.8(2) pm, Rh(2)–C(26) 208.9(3) pm, Rh(2)–C(25) 209.4(3) pm, Rh(2)–C(21) 209.9(2) pm, Rh(2)–C(22) 209.9(3) pm, N(2)–
2
Rh(1)–N(1) 83.58(7)° and 2 (right) Ir(1)–C(5) 207.0(8) pm, Ir(1)–C(6) 209.2(9) pm, Ir(1)–N(2) 212.6(6) pm, Ir(1)–N(3) 213.4(6) pm, Ir(1)–C(1) 214.4(2) pm,
Ir(1)–C(2) 218.3(2) pm, Ir(1)–Cl(1) 253.91(2) pm, N(2)–Ir(1)–N(3) 83.7(2)°.

5274
B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
Rh-based catalysts work at lower temperatures and are
therefore often the preferred systems [13,14]. Usually,
phosphane-based ligands are used, since they offer access
to highly active systems and allow regio-, and in case of
chiral phosphanes, even enantioselective reactions
[
15–24]. During the last two decades, environmental
aspects including catalysts and solvent recycling became
an issue. Therefore, supported [25–32], water soluble [33]
or biphasic systems [34–36], as realized in the Rhone–Pou-
lenc process, have been developed [37–40]. Alternatively,
the use of ionic liquids [41–45] or supercritical CO has
2
been reported [46]. Since phosphanes and CO show similar
binding constants for rhodium and high CO pressures are
applied during hydroformylation, an excess of phosphane
is required in order to generate a sterically demanding envi-
ronment around the metal center, a prerequisite for high
selectivities. In order to determine the scopes and limits
of the dipyridyl amide system, we were interested, whether
the corresponding Rh-complex 1 was in principle suited for
this type of reaction.
Fig. 3. Formation of isomeric octenes from 1-octene under hydroformy-
lation conditions in the presence of 1: s/s
3-octene, (m) 4-octene, (h) isomer of 1-octene.
0
, (n) 1-octene, (.) 2-octene. (d)
For this purpose, compound 1 was used in the hydro-
formylation of both cyclooctene and 1-octene. Solutions
of 1 and the corresponding olefin in toluene were treated
with CO and H (1:1) at 50 bar at 100 and 70 °C, respec-
2
tively. It is worth notifying that 1 does not rearrange into
1
a in toluene, even at elevated temperature. Cyclooctene
reacts smoothly under these conditions to form cyclooc-
tane carbaldehyde. Fig. 2 illustrates the formation of
cyclooctane carbaldehyde. A total TON of 1800 was
obtained after 10 h, corresponding to an average turn-over
ꢀ
1
frequency of 180 h
.
In case 1-octene was subject to hydroformylation, it was
isomerized to the corresponding alkenes (Fig. 3), giving
raise to the formation of 1-nonanal as well as the isomeric
C-9 aldehydes (Fig. 4). After 3 h, 1-octene was fully con-
verted to the corresponding aldehydes. Due to the ongoing
isomerization process of 1-octene, the n:iso ratio was time
Fig. 4. Conversion (%) of 1-octene and product formation under
hydroformylation conditions in the presence of 1 as well as time-
dependant n:iso ration: s/s , (n) 1-octene, (d) nonanal, (m) 1-methyloct-
0
anal, (s) 2-methylheptanal, (.) 2-propylhexanal.
dependant and decreased from 2.5 to 0.8. Such a (variable,
time dependant) ratio is in view of the comparably low
steric demand of the ligand not surprising at all and is com-
I
parable to the one found for Rh -1,3-R -3,4,5,6-tetrahy-
2
dropyrimidin-2-ylidenes (R = 2-Pr, mesityl), which gave
raise to a final n:iso ratio of 0.9–1.4 [47]. The total TON
after 4 h was found to be 4800. This corresponds to a
ꢀ
1
ꢀ1
TOF of 1200 h . The TOF was found to be 1400 h
,
0
which is again comparable to the TOF found for Rh-tet-
0
rahydropyrimidin-2-ylidenes [47] (see Fig. 5 and Scheme 2).
2.3. Carbonyl hydrosilylation reactions
Compound 1 was further used for the hydrosilylation of
Fig. 2. Cyclooctane carbaldehyde formation from cyclooctene under
hydroformylation conditions in the presence of 1.
carbonyl compounds (Scheme 3, Table 1).

B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
5275
into turn-over numbers (TONs) of 50000. Yields for
ketones were in the range of 85–97%, translating into
turn-over numbers (TONs) of 42500–48500. The results
obtained here are comparable to those obtained with
Cu(I) complexes of 1,3-di(2-propyl)3,4,5,6-tetrahydropyr-
imidin-2-ylidene and 1,3-dimesityl-3,4,5,6-tetrahydropyr-
imidin-2-ylidene [48] (see Scheme 4).
2.4. Polymerization of ethyl diazaacetate
The polymerization of diazo compounds by various
I
Rh complexes has attracted significant interest since it
provides an attractive access to ‘‘substituted poly(methy-
lene)’’ [49,50], the more as these polymerization may be
carried out in a stereoselective way. Polymerization of
ethyl diazoacetate using 1 yielded poly(ethyloxycarbonyl-
carbene) with an M of 67000 g/mol and a polydispersity
w
Fig. 5. Product distribution of the hydroformylation of 1-octene as a
index (PDI) of 2.59. As also reported by de Bruin, the
corresponding Ir-complex 2 does not promote the poly-
merization of ethyl diazoacetate. Similarly, reaction of 1
with trimethylsilyldiazoacetate does not result in the for-
mation of isolable amounts of polymer. As observed for
other Rh-catalysts [49,50], the polymerization of ethyl dia-
zoacetate by 1 does not proceed in a living or even con-
trolled manner as is evidenced by the low yields and the
higher PDI value. In addition, there is no correlation
between amount of the catalyst and monomer with the
molecular weight. Instead, maintaining a low concentra-
tion of monomer appears to be a crucial point in polymer
function of time using 1 as the catalyst.
1
Scheme 2. Hydroformylation of 1-octene by the action of 1.
synthesis. To our great pleasure, both the H and
1
3
C NMR of the polymer (Fig. 6) are identical with the
ones obtained by de Bruin [49,50], thus indicating the for-
mation of a highly stereoregular, presumably syndiotactic
polymer.
This finding and the absence of any chiral center in the
ligand strongly supports the chain end control mechanism
proposed by de Bruin [49,50].
Scheme 3. Hydrosilylation of carbonyl compounds.
Table 1
Summary of carbonyl hydrosilylation results
#
Substrate
t (h) TON
GC yield (%)
50000 100
50000 100
42,500 85
1
2
3
4
5
6
7
8
9
Benzaldehyde
4-Fluorobenzaldehyde
Benzoin
p-N,N dimethylaminobenzaldehyde 0.5
4-Chlorobenzaldehyde
Benzophenone
Benzil
3-Hydroxybenzaldehyde
3-Chloropropiophenone
0.5
0.5
1.5
50000 100
50000 100
1
2 2 5
Scheme 4. Polymerization of N CHCOOC H by the action of 1.
1.5
4
48500
40000
97
80
0.5
1.5
50000 100
44000 88
As can be deduced from Table 1, both aldehydes and
ketones were successfully converted into the corresponding
triethylsilyloxy compounds using low catalyst loadings, i.e.
2
mmol% (0.002 mol%) of 1. Yields for aldehydes as deter-
1
3
mined by GC–MS were virtually quantitative, translating
Fig. 6. C NMR of poly(ethyloxycarbonylcarbene).

5276
B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
3
. Experimental
(ATR mode): ꢀm ¼ 1688 (t
), 1597 (m), 1461 (s), 1431
C@O
s), 1364 (s), 1271 (br), 992 (br), 759 cm (m). Elemental
ꢀ1
(
3
.1. General
Anal. Calc. for C H ClN ORh: C, 52.25; H, 5.04; N,
20 23 3
9.14. Found: C, 52.0; H, 5.15; N, 9.15%. MS (ESI) m/z
All manipulations were performed under a nitrogen
calc. for C H ClN ORh: 459.06. Found: 424.09
(M ꢀCl).
2
2
29
3
+
atmosphere in a glove box (MBraun LabMaster 130) or
by standard Schlenk techniques. Triethylsilane was dried
over molecular sieves and distilled under argon. Tetra-
hydrofurane (THF), dichloromethane and toluene were
dried and purified by an MBraun SPS drying system. Cyc-
3.4. Conversion of 1 into
[Rh(CH CONPy )(COD) RhCl (COD) ] (1a)
+
ꢀ
3
2
2
looctene and 1-octene were dried over CaH and distilled
1 was dissolved in methylene chloride and stored at
ꢀ36 °C for several days. A precipitate formed that could
not be dissolved in methylene chloride again. Recrystalliza-
2
under argon. NMR data were obtained at 250.13 MHz
for proton and 62.90 MHz for carbon in the indicated sol-
vent at 25 °C on a Bruker Spectrospin 250 and are listed in
parts per million downfield from tetramethylsilane. IR
spectra were recorded on a Bruker Vector 22 using ATR
technology.
tion from acetonitrile:diethyl ether yielded orange crystals
1
suitable for X-ray analysis. H NMR (CDCl ): d = 1.72
3
(m, br, 8H of COD-CH ), 2.23 (br, CH ), 2.47 (m, br,
2
3
8H of COD-CH ), 4.14 (s, br, 4H, COD-CH), 7.27, 7.58,
2
1
3
7
.81, 8.57 (8H of Py). C NMR (CDCl ): d = 24.18,
3
3.2. Synthesis of N,N-dipyrid-2-yl acetamide (modified
procedure)
30.97 (br), 78.35 (br), 78.54 (br), 123.22 (br), 137.77,
150.25, 170.62 (CO); FT-IR (ATR mode): ꢀm ¼ 2914 (br),
1
694 (t
, m), 1598 (m), 1461 (m), 1365 (m), 1272 (br),
C@O
ꢀ
1
The compound was prepared via a modified literature
992 (br), 955 (br), 726 cm (m).
procedure [1]. In a 250 mL two neck round bottomed flask,
N,N-dipyridylamine (2.0 g, 11.7 mmol), triethylamine
3.5. N-acetyl-N,N-dipyrid-2-yl (cyclooctadiene) iridium
chloride
(
1.30 g, 12.8 mmol) were dissolved in 15 mL of dichloro-
methane. To this mixture, at ꢀ20 °C, acetyl chloride
1.70 g, 21.8 mmol), dissolved in 10 mL of dichlorometh-
(
N,N-dipyrid-2-yl acetamide (70.0 mg, 0.3286 mmol) was
ane, was added dropwise. After addition was completed,
stirring was continued for a few more minutes, then the
reaction mixture was warmed to room temperature. The
reaction mixture was poured on saturated sodium bicar-
bonate solution and twice extracted with dichloromethane.
The combined organic fractions were dried over Na SO ,
the solution was filtered and the solvent was removed in
vacuo. The crude product mixture was passed over a short
silica gel column using dichloromethane:diethyl ether (4:96
by vol.) as the mobile phase. The product was recrystallized
from dichloromethane/n-pentane, yielding 1.7 g (68%) of 1.
Spectroscopic data were in accordance with those reported
dissolved in dichloromethane. This solution was added
dropwise to one of [Ir(COD)Cl] (110.0 mg, 0.165 mmol)
2
in dichloromethane (5 mL). The mixture was stirred for
3 h at room temperature and then filtered through glass
fiber paper. The solvent was removed in vacuo and the
product was obtained in pure form as a red colored solid.
Crystals suitable for X-ray analysis were grown from
2
4
1
CH Cl : diethyl ether. Yield: 162.0 mg (90.0%). H NMR
2
2
(CDCl ): d = 1.49 (br, 4H of COD-CH ), 2.23 (s, 7H, 4H
3
2
of COD-CH and 3H of CH ), 3.32 (br, 4H of COD),
2
3
1
3
7.34, 7.59, 7.85, 8.74 (m, 8H of Py). C NMR (CDCl3):
d = 22.68, 31.98 (br), 57.02, 122.13, 124.02, 126.01,
138.24, 139.11, 149.13, 150.56, 152.48, 169.60 (CO); FT-
IR (ATR mode): ꢀm ¼ 1695 (tC@O), 1461 (s), 1432(s),
[
1].
ꢀ
1
3.3. N-acetyl-N,N-dipyrid-2-yl (cyclooctadiene) rhodium
chloride
1320(s), 1268 (s) cm .
3.6. Hydroformylation reactions
N,N-dipyrid-2-yl acetamide (70 mg, 0.33 mmol) was dis-
solved in dichloromethane. This solution was added drop-
wise to a solution of [Rh(COD) Cl] (81.5 mg, 0.165 mmol)
The reaction was carried out in a 300 mL Parr high-
pressure reactor. The reactor was evacuated, flushed with
2
2
ꢀ
5
in dichloromethane. The mixture was stirred for 3 h at
room temperature, then it was filtered through glass fiber
filter paper and the solvent was removed in vacuo. Analyt-
ically pure product was obtained as a yellow colored solid
in 95% yield (143.0 mg). Crystals suitable for X-ray analy-
argon and filled with the rhodium complex (1) 10 mol,
toluene (20 mL), 1-octene and cyclooctene, respectively
(1.0 g, 0.009 mol), leading to a substrate to catalyst ratio
of 5000:1, then tert-butylbenzene was added as internal
standard. The mixture was pressurized with a 1:1 mixture
1
sis were obtained from acetonitrile:diethyl ether H NMR
of CO and H up to a pressure of 30 bar to clean all sup-
2
(
CDCl ): d = 1.72 (m, 4H of COD-CH ), 2.15 (s, CH ),
plies before the pressure was adjusted to 50 bar with a back
pressure regulator. Samples were taken every 30 min and
products were quantified by gas chromatography. The tem-
perature was set to 100 °C for the hydroformylation of
3
2
3
2
7
3
.5 (m, 4H of COD-CH ), 4.2 (s, 2H, COD-CH), 7.22,
2
1
3
.5, 7.78, 8.48 (8H of Py). C NMR (CDCl ): d = 24.5,
3
0.97, 78.4, 122.5 (br), 138.5, 149.3, 170.7 (CO); FT-IR

B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
5277
cyclooctene and to 70 °C for the hydroformylation of 1-
octene. Molar ratios of cyclooctene:1 and 1-octene:1 of
1a and for most of the non-hydrogen atoms of 2. In the
asymmetric unit of 2 are two independent molecules, both
showing a 1:1 position disorder of the COD molecule with
partial overlying positions at the first and separate posi-
tions at the second molecule. Because of the nearly overly-
ing positions of these COD molecules, most of the carbon
atoms were refined with isotropic displacement parameters.
Positions of hydrogen atoms were calculated except for
those at the double bonds of the COD molecules of 1a,
which were found and refined normal with isotropic dis-
placement parameters.
2
000 and 5000, respectively, were used. Cyclooctene, the
isomeric octenes as well as the isomeric aldehydes very
identified by their MS spectra as well as by their retention
times using commercially available compounds as reference
material. Quantification was accomplished using tert-butyl-
benzene as an internal standard.
3
.7. Typical procedure for hydrosilylation reactions
In
a 50 mL Schlenk tube the catalyst (4.4 mg,
2
.0 mmol%) was dissolved in 1.0 mL of THF, sodium
Acknowledgements
tert-butoxide (4.5 mg, 10 mmol%) and 3.0 mol equivalents
of triethylsilane (164 mg, 1.42 mmol) were added and the
solution was stirred for 5 min. Then a solution of benzalde-
hyde (50 mg, 0.47 mmol) in 2.0 mL of THF was added to
the reaction mixture. The solution was heated to 70 °C.
Product conversion was monitored by GC–MS at defined
time intervals. Compounds were identified by GC–MS.
Quantification was accomplished using tert-butylbenzene
as an internal standard.
Our work was supported by a Grant of the Deutsche
Forschungsgemeinschaft (DFG) and by the Freistaat
Sachsen.
Appendix A. Supplementary material
CCDC 649693 and 649694 contain the supplementary
crystallographic data for 1a and 2. These data can be
obtained free of charge via http://www.ccdc.cam.ac.uk/
conts/retrieving.html, or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2
1EZ, UK, fax: (+44) 1223-336-033, or e-mail: depos-
it@ccdc.cam.ac.uk. Supplementary data associated with
this article can be found, in the online version, at
doi:10.1016/j.jorganchem.2007.08.009.
3
.8. Polymerization of diazo compounds
1
6.0 mg (2.0 mmol%) of the catalyst were dissolved
in 2.0 mL of 1,2 dichloroethane. Ethyl diazoacetate
200.0 mg, 1.76 mmol) was dissolved in 3.0 mL of 1,2
(
dichloroethane. This solution was added slowly drop wise
to the catalyst solution. The reaction mixture was stirred
for 4 h at 65 °C, after the reaction the solvent was removed
in vacuo and the residue was recrystallized from dichloro-
methane and pentane. Yield 25.0%.
References
[
[
1] M.R. Buchmeiser, K. Wurst, J. Am. Chem. Soc. 121 (1999) 11101.
2] J. Silberg, T. Schareina, R. Kempe, K. Wurst, M.R. Buchmeiser, J.
Organomet. Chem. 622 (2001) 6.
3
.9. Poly(ethyloxycarbonylmethylene)
[3] M.R. Buchmeiser, T. Schareina, R. Kempe, K. Wurst, J. Organomet.
Chem. 634 (2001) 39.
FT-IR (ATR mode): ꢀm ¼ 2980 (br), 1724 (CO, s), 1153
[4] M.R. Buchmeiser, S. Lubbad, M. Mayr, K. Wurst, Inorg. Chim.
Acta 345 (2003) 145.
ꢀ
1 1
m), 1026 (m), 859 (m) cm . H NMR (CDCl ) d 1.22
(
2
(
(
3
[
5] C. N a´ jera, J. Gil-Molt o´ , S. Karlstr o¨ m, L.R. Falvello, Org. Lett. 5
2003) 1451.
broad t, 3H of CH ), 3.15 (broad s, 1H, CH), 4.06 (broad,
3
(
1
3
H of CH2); C NMR (CDCl ) d 13.96, 45.5, 60.82, 170.91
3
[6] T. Schareina, G. Hilebrand, H. Fuhrmann, R. Kempe, Eur. J. Inorg.
Chem. (2001) 2421.
CO). M = 25800 g/mol, M = 67000 g/mol, PDI = 2.59.
n w
[
[
7] J. Gil-Molt o´ , S. Karlstr o¨ m, C. N a´ jera, Tetrahedron 61 (2005) 12168.
8] K. Weissermel, H.J. Arpe, Industrial Organic Chemistry, VCH, New
York, 1993.
3.10. X-ray measurement and structure determination of 1a
and 2
[
9] P. Eilbracht, L. B a¨ rfacker, C. Buss, C. Hollmann, B.E. Kitsos-
Rzychon, C.L. Kranemann, T. Rische, R. Roggenbuck, A. Schmidt,
Chem. Rev. 99 (1999) 3329.
Data collection were performed on a Nonius Kappa
CCD equipped with graphite-monochromatized Mo Ka-
radiation (k = 0.71073 A) and a nominal crystal to area
[10] B. Cornils, W.A. Herrmann (Eds.), Applied Homogeneous Catalysis
with Organometallic Compounds, Wiley-VCH, Weinheim, 1996.
˚
[
11] B. Cornils, W.A. Herrmann, R.W. Eckl, J. Molec. Catal. A: Chemical
16 (1997) 27.
detector distance of 36 mm. Intensities were integrated
using DENZO and scaled with SCALEPACK [51]. Several
scans in / and x direction were made to increase the num-
ber of redundant reflections, which were averaged in the
refinement cycles. This procedure replaces in a good
approximation an empirical absorption correction. The
structures were solved with direct methods SHELXS86 and
1
[
12] B. Cornils, W.A. Herrmann, I.T. Horv a´ th, W. Leitner, S. Mecking,
H. Olivier-Bourbigou, D. Vogt (Eds.), Multiphase Homogeneous
Catalysis, Weinheim, 2005.
[
13] J. Bakos, S. Cser e´ pi-St u¨ cs, A. G o¨ m o¨ ry, C. Heged u¨ s, L. Mark o´ , A.
Sz o¨ ll o¨ sy, Can. J. Chem. 79 (2001) 725.
[
[
14] F. Ungvary, Coord. Chem. Rev. 249 (2005) 2946.
15] R. Ewalds, E.B. Eggeling, A.C. Hewat, P.C.J. Kamer, P.W.N.M.
van Leeuwen, D. Vogt, Chem. Eur. J. 6 (2000) 1496.
2
refined against F SHELX97 [52]. All non-hydrogen atoms
were refined with anisotropic displacement parameters for
[16] G. Francio, W. Leitner, Chem. Commun. (1999) 1663.

5278
B. Bantu et al. / Journal of Organometallic Chemistry 692 (2007) 5272–5278
[
[
[
[
[
[
[
17] H.S. Park, E. Alberico, H. Alper, J. Am. Chem. Soc. 121 (1999)
1697.
18] F. Agbossou, J.-F. Carpentier, A. Mortreux, Chem. Rev. 95 (1995)
485.
19] K. Nozaki, Y. Itoi, F. Shibahara, E. Shirakawa, T. Ohta, H. Takaya,
T. Hiyama, J. Am. Chem. Soc. 120 (1998) 4051.
20] U. Nettekoven, P.C.J. Kramer, M. Widhalm, P.W.N.M. van Leewen,
Organometallics 22 (2000) 4596.
21] K. Nozaki, T. Matsuo, F. Shibahara, T. Hiyama, Adv. Synth. Catal.
[36] S.L. Desset, D.J. Cole-Hamilton, D.F. Foster, Chem. Commun.
(2007) 1933.
[37] W.A. Herrmann, C.W. Kohlpainter, Angew. Chem., Int. Ed. Engl. 32
(1993) 1524.
[38] W.A. Herrmann, B. Cornils, Homogeneous Catalysis-Quo Vadis?
VCH, Weinheim, 1996.
[39] P. Kalck, M. Dessoudeix, Coord. Chem. Rev. 190–192 (1999)
1185.
[40] A.M. Trzeciak, J.J. Ziolkowski, Coord. Chem. Rev. 190–192 (1999)
883.
[41] C.C. Brasse, U. Englert, A. Salzer, H. Waffenschmidt, P. Wassersc-
heid, Organometallics 19 (2000) 3818.
[42] P. Wasserscheid, W. Keim, Angew. Chem. 112 (2000) 3927.
[43] P. Wasserscheid, H. Waffenschmidt, J. Mole. Catal A: Chem. 164
(2000) 61.
[44] C.P. Mehnert, R.A. Cook, N.C. Dispenziere, E.J. Mozeleski, Poly-
hedron 23 (2004) 2679.
1
2
343 (2001) 61.
22] S. Breeden, D.J. Cole-Hamilton, D.F. Foster, G.J. Schwarz, M.
Wills, Angew. Chem. 112 (2000) 4272.
23] H. Klein, R. Jackstell, K.-D. Wiese, C. Borgmann, M. Beller, Angew.
Chem. 113 (2001).
[
[
[
24] B. Breit, Acc. Chem. Res. 36 (2003) 264.
25] A.N. Ajjou, H. Alper, J. Am. Chem. Soc. 120 (1998) 1466.
26] S.C. Bourque, F. Maltais, W.-J. Xiao, O. Tardif, H. Alper, P. Arya,
L.E. Manzer, J. Am. Chem. Soc. 121 (1999) 3035.
27] S.C. Bourque, H. Alper, J. Am. Chem. Soc. 122 (2000) 956.
28] A.L. Sandee, L.A. van der Veen, J.N.H. Reek, P.C.J. Kamer, M. Lutz,
A.L. Spek, P.W.N.M. van Leeuwen, Angew. Chem. 111 (1999) 3429.
29] A.J. Sandee, J.N.H. Reek, P.C.J. Kamer, P.W.N.M. van Leeuwen, J.
Am. Chem. Soc. 123 (2001) 8468.
[45] A. Riisager, R. Fehrmann, S. Flicker, R. van Hal, M. Haumann, P.
Wasserscheid, Angew. Chem. 117 (2005) 826.
[46] N.J. Meehan, A.J. Sandee, J.N.H. Reek, P.C.J. Kamer, P.W.N.M.
van Leewen, M. Poliakoff, Chem. Commun. (2000) 1497.
[47] M. Bortenschlager, M. Mayr, O. Nuyken, M.R. Buchmeiser, J.
Mole. Catal. A: Chem. 233 (2005) 67.
[
[
[
[
[
30] Y.I. Yermakov, J. Mol. Catal.: A Chem. 21 (1983) 35.
31] M. Nowotny, T. Maschmeyer, B.F.G. Johnson, P. Lahuerta, J.M.
Thomas, J.E. Davis, Angew. Chem. 113 (2001).
[48] B. Bantu, K. Wurst, M.R. Buchmeiser, Tetrahedron Symp. 61 (2005)
12145.
[49] D.G.H. Hetterscheid, C. Hendriksen, W. Dzik, J.M.M. Smits,
E.R.H. van Eck, A.E. Rowan, V. Busico, M. Vacatello, V. Van Axel
Castelli, A. Segre, E. Jellema, T.G. Bloemberg, B. de Bruin, J. Am.
Chem. Soc. 128 (2006) 9746.
[50] A.F. Noels, Angew. Chem. 119 (2007) 1228.
[51] Z. Otwinowski, W. Minor, Methods in Enzymology, Academic Press,
New York, 1997.
[52] G.M. Sheldrick, Program Package SHELXTL V.5.1, Bruker Analytical
X-ray Instruments Inc, Madison, USA, 1997.
[
[
[
[
32] K. Mukhopadhyay, A.B. Mandale, R.V. Chaudhari, Chem. Mater.
1
5 (2003) 1766.
33] S. Shimizu, S. Shirakawa, Y. Sasaki, C. Hirai, Angew. Chem. 112
2000) 1313.
(
34] M. Marchetti, G. Mangano, S. Paganelli, C. Botteghi, Tetrahedron
Lett. 41 (2000) 3717.
35] M. Schreuder Goedheijt, B.E. Hanson, J.N.H. Reek, P.C.J. Kamer,
W.N.M. Leeuwen, J. Am. Chem. Soc. 122 (2000) 1650.