Long-chain linear C19 and C23 monomers and polycondensates from unsaturated fatty acid esters

Article abstract of DOI:10.1021/ma200627e

Isomerizing alkoxycarbonylation of methyl oleate and ethyl erucate, respectively, yielded dimethyl 1,19-nonadecanedioate and diethyl 1,23-tricosanedioate in >99% purity. With [κ²-(P P)Pd(OTf)][OTf] as a defined catalyst precursor (PP = 1,2-bis[(di-tert- butylphosphino)methyl]benzene) the reaction can be carried out without the need for additional added diphosphine. Saponification of the diesters yielded 1,19-nonadecanedicarboxylic acid and 1,23-tricosanedicarboxylic acid in >99% purity. By ruthenium-catalyzed reduction of the diesters with H₂, 1,19-nonadecanediole and 1,23-tricosanediole were formed in high yield and purity (>99%). From the latter, 1,19-nonadecanediamine and 1,23-tricosanediamine were generated. Polyesters with commercially available shorter-chain petrochemical or renewable diols exhibit high melting points due to the crystallizable long-chain methylene segments from the dicarboxylic acid component, e.g., poly[1,6-hexadiyl-1,23-tricosanedioate] T_m 92, T_c 75 °C. Thermal properties of novel long-chain polyamides are reported.

Full text of DOI:10.1021/ma200627e

ARTICLE
pubs.acs.org/Macromolecules
Long-Chain Linear C and C Monomers and Polycondensates from
23
19
Unsaturated Fatty Acid Esters
Florian Stempfle, Dorothee Quinzler, Ilona Heckler, and Stefan Mecking*
Chair of Chemical Materials Science, Department of Chemistry, University of Konstanz, 78464 Konstanz, Germany
S Supporting Information
b
ABSTRACT: Isomerizing alkoxycarbonylation of methyl ole-
ate and ethyl erucate, respectively, yielded dimethyl 1,19-
nonadecanedioate and diethyl 1,23-tricosanedioate in >99%
2
^
purity. With [k -(P P)Pd(OTf)][OTf] as a defined catalyst
^
precursor (PP = 1,2-bis[(di-tert-butylphosphino)methyl]ben-
zene) the reaction can be carried out without the need for
additional added diphosphine. Saponification of the diesters
yielded 1,19-nonadecanedicarboxylic acid and 1,23-tricosane-
dicarboxylic acid in >99% purity. By ruthenium-catalyzed
reduction of the diesters with H , 1,19-nonadecanediole and 1,23-tricosanediole were formed in high yield and purity (>99%).
2
From the latter, 1,19-nonadecanediamine and 1,23-tricosanediamine were generated. Polyesters with commercially available
shorter-chain petrochemical or renewable diols exhibit high melting points due to the crystallizable long-chain methylene segments
from the dicarboxylic acid component, e.g., poly[1,6-hexadiyl-1,23-tricosanedioate] T 92, T 75 °C. Thermal properties of novel
m
c
long-chain polyamides are reported.
’
INTRODUCTION
thermoplastic processing applications. The terminal functionali-
zation of fatty acids, or their derivatives like esters, is a formidable
challenge. One possible solution is enzymatic ω-oxidation. Here-
by, e.g., stearic acid is converted to 1,18-octadecane dicarboxylic
Today's polymer production relies almost exclusively on
fossil feedstocks. This applies particularly to thermoplastic
polymers, which represent the largest type of industrial poly-
mers before thermosets and elastomers. In view of the limited
range of fossil feedstocks, polymers prepared from alternative
renewable resources are desirable on the long-term. Current
examples of polymers based on renewable resources are cellu-
lose esters and ethers, and poly(lactic acid) and poly(hydroxy
alkanoates), which have been launched more recently on a large
scale. Also, sugar cane based polyethylene is now produced
industrially. These polymers are all based on carbohydrate
feedstocks.
8
acid. Problems to be solved are limited spaceꢀtime yields and
the need to nurture the catalytically active microorganims with
1
,2
costly glucose. Alternatively, ω-hydroxy fatty acids can be
9
obtained by fermentation with modified yeast strains. We have
recently communicated an entirely chemical route for the pre-
paration of R,ω-dicarboxylic acid esters with polymerization
10
grade purity from unsaturated fatty acids. Isomerizing
11
alkoxycarbonylation converts the internal double bond deep
in the hydrocarbon chain to a terminal ester group highly
selectively, as noted first by Cole-Hamilton et al. for unsaturated
3,4
Fatty acids from plant oils are attractive substrates for polymers
12
fatty acids, to yield linear (odd-carbon number) products.
Polyesters prepared from these long-chain dicarboxylic acids by
polycondensation with diols generated from the former by
reduction, namely poly[1,19-nonadecadiyl-1,19-nonadecanedi-
oate] and poly[1,23-tricosadiyl-1,23-tricosanedioate], possess
melting points and crystallization temperatures that compare
with typical thermoplastics.
as they contain long chain linear segments. Thus, Nylon-11 has
been prepared for nearly fifty years from ricinoleic acid. Likewise,
sebacic acid, which is polymerized to Nylon-6,10 but also applied for
example in corrosion inhibition, is generated by base-catalyzed
5
6
cleavage of ricinoleic acid. However, both routes utilize only
about half of the fatty acid molecule, and thus only partially
incorporate the latter in the polyamide chains (also, they require
a hydroxy substituted unsaturated fatty acid, of which ricinoleic
acid is the only practically available example). A full linear
incorporation of the entire fatty acid chain would be desirable,
as this would not only utilize the feedstock most efficiently but
also employ the potential of the long-chain linear feedstock to
provide crystallizable segments. This is important, as aliphatic
polyesters accessible from current diacid and diol monomers,
based on petrochemical as well as renewable feedstocks, suffer
We here give a full account on the synthesis of a range of R,
ω-functionalized long chain linear compounds based on isomer-
izing alkoxycarbonylation of fatty acids, and of novel polycon-
densates thereof.
Received: March 18, 2011
Revised:
April 19, 2011
7
from low melting points, which make them unsuitable for
Published: May 09, 2011
r 2011 American Chemical Society
4159
dx.doi.org/10.1021/ma200627e
|Macromolecules 2011, 44, 4159–4166

Macromolecules
ARTICLE
Scheme 1. Long-Chain r,ω-Difunctional Compounds from Unsaturated Fatty Acids (x = 1, Oleic Acid as Starting Material; x = 5,
Erucic Acid)
Table 1. Isomerizing Methoxycarbonylation of Methyl Ole-
a
ate with Different Catalyst Systems
d
e
entry
catalyst
substrate
% conversion
2
c
c
1
2
3
4
[k -( P^ P)Pd(OTf)
2
]
]
methyl oleate (75%)
methyl oleate (99%)
methyl oleate (75%)
methyl oleate (99%)
36
80
28
52
2
[k -( P^ P)Pd(OTf)
2
b
b
Pd(OAc)
Pd(OAc)
2
/dtbpx/MSA
/dtbpx/MSA
2
a
Conditions: 12 μmol of Pd, Pd to methyl oleate ratio 1:500, 10 mL of
b
MeOH, 20 bar CO, 90 °C, 22 h. 12 μmol of Pd(OAc) , 60 μmol of
diphosphine, 500 μmol of methanesulfonic acid (MSA). 12 μmol of
2
c
d
[
(dtbpx)Pd(OTf) ]. Purity of the starting material given in brackets.
2
e
Conversions, referring to the total mass of the starting material, are
1
calculated from the H NMR spectrum of the crude reaction mixture.
Entries 3 and 4 are taken from ref 10.
2
^
[
k -(P P)PdH(L)]. To achieve reasonable activities, a ca. 5-fold
1
3
excess of the costly diphosphine was required in the work of
1
2
10
2
Cole-Hamilton as well as in our hands, that is P:Pd = 10:1.
While the background for this remains unclear, we reasoned
that a defined coordination of the diphosphine in the catalyst
precursor might obliviate the need for additional phosphine. A
triflate complex was studied as a catalyst precursor, as the
relatively weak coordination of triflate should provide a high
^
Figure 1. ORTEP plot of [k -(P P)Pd(OTf)][OTf] (1). Ellipsoids are
shown with 50% probability. Hydrogen atoms, as well as the triflate
counterion are omitted for clarity.
’
RESULTS AND DISCUSSION
2
14
Beyond their direct utilization as polycondensation mono-
reactivity. The ditriflate complex [k -( P^ P)Pd(OTf) ] (1)
2
mers, the R,ω-diesters are also of interest for the preparation of
other difunctional compounds (Scheme 1). While these conver-
sions principally rely on known chemistry, application to these
long-chain compounds in some instances needs to consider that
the substrates and the products can differ strongly from lower
molecular weight analogues concerning their solubility and
physical properties (T , T ) and require suitable reaction and
was obtained by halide abstraction from the corresponding
2
dichloro complex [k -( P^ P)PdCl ]. X-ray diffraction (Figure 1)
2
reveals that only one triflate ligand is coordinated to the metal
center, via two of its oxygen atoms, while the second triflate
functions as a noncoordinated counterion, that is 1 is best
2
described as [k -( P^ P)Pd(OTf)][OTf].
m
v
A remarkably enhanced catalyst performance was observed
with this defined catalyst precursor (Table 1). At a palladium to
methyl oleate ratio of 1:500, which much exceeds the 1:60
workup conditions.
Isomerizing Alkoxycarbonylation. Previous studies of al-
koxycarbonylation of internal olefins employed an in situ cata-
lyst system, consisting of a palladium source mixed with the
diphosphine ligand 1,2-bis[(di-tert-butylphosphino)methyl]-
benzene (dtbpx). The active species formed is very likely
1
0,12
catalyst to substrate ratio employed in previous studies,
80% of the fatty acid methyl ester is selectively converted to
the R,ω-diester using the ditriflate complex (entry 2), whereas
the aforementioned in situ catalyst system with excess phosphine
4
160
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Macromolecules
ARTICLE
Figure 3. Comparison of the melting points of different polyesters
obtained by polycondensation of dimethyl-1,19-nonadecanedioate and
diethyl-1,23-tricosanedioate (this work), and of azelaic, pimelic, and
glutaric acid (from ref 7a) with R,ω-diols of different chain lengths.
Dashed lines are merely a guide to the eye.
Figure 2. Diethyl 1,23-tricosanedioate from isomerizing ethoxycarbo-
nylation of erucic acid.
in three steps: mesylate formation, azide substitution, and
catalytic reduction (cf. Scheme 1). The poorly soluble long-
chain aliphatic diamines could be both isolated after repeated
filtration over a B €u chner funnel at 50 °C to remove catalyst
residues, and recrystallization from ethanol in an overall yield of
about 65%. This three-step synthesis is convenient on a labora-
tory scale, also due to the relatively high molecular weight per
functional group of the long-chain compounds, which limits the
amount of tosylate and azide reagent required. On the longer
term, routes to the diamines employing lower cost reagents and
requiring fewer steps are desirable, such as amidation with
ammonia and hydrogenation.
only converted 50% (entry 4). Similar results were obtained
utilizing readily available technical grade methyl oleate as a
starting material (entries 1 and 3).
By comparison toourprevious report, in which the R,ω-diesters
were obtained in amounts of ca. 1.5 g, performing the alkoxycar-
bonylation on a larger scale in a 300 mL reactor yielded the
products in an amount of ca. 25 g per experiment without any
adverse effects on purity or yield (Figure 2 and Experimental
Section).
r,ω-Diols. In our preliminary studies, reduction of the diesters
to the diols was achieved by means of the inorganic hydride
LiAlH . While this satisfactorily afforded the products in high
Polyesters with Variable Chain Length Diols. We have
previously communicated the synthesis and properties of the
novel polyesters poly[1,19-nonadecadiyl-1,19-nonadecanedi-
oate] and poly[1,23-tricosadiyl-1,23-tricosanedioate], based on
the long-chain diacids and diols. These polyesters possess
melting points >100 °C and crystallization temperatures around
90 °C, which compares with typical thermoplastics. For aliphatic
polycondensates of shorter chain diols, crystallinity should pri-
marily arise from the long-chain diacid component. To this end,
the C and C diacid, respectively, were condensed with hexane-
4
purity, removal of the inorganic salts requires a tedious workup,
and also on a larger scale the cost of LiAlH would be prohibitive.
4
15
Saudan’s ruthenium catalyst, which has been reported to
reduce esters with H to alcohols selectively under relatively
2
mild conditions, was found to be suited also for the long-chain
substrates subject to this work. Nonadecane-1,19-diol as well as
tricosane-1,23-diol both were formed in high yield and with
1
more than 99% purity (from H NMR) via homogeneously
catalyzed hydrogenolysis of the corresponding R,ω-diesters with
dichlorobis[2-(diphenylphosphino)ethylamine]ruthenium at
19
23
1,6-diol and with dodecane-1,12-diole, catalyzed by titanium
p(H ) = 50 bar and a reaction temperature of 100 °C, employing
alkoxides. Molecular weights of the resulting polyesters as
2
1
a high substrate to catalyst ratio of 1000:1. Note that under the
reaction conditions the starting material is soluble in the THF
solvent employed. Thus, the diols are available in high purity and
good yields via a sequence of two effective and selective catalytic
reactions from the unsaturated fatty acids, employing only metha-
nol or ethanol, respectively, carbon monoxide, and hydrogen as
reagents.
determined by H NMR spectroscopic analysis of the end groups
4
ꢀ1
are around M 10 g mol . All the materials prepared are
n
semicrystalline and thermal analyses reveal melting points from
86 to 100 °C and crystallization temperatures from 72 to 76 °C
(Figure 3 and Experimental Section).
By comparison to polycondensates of shorter chain diacids,
the melt and crystallization temperatures of the novel polyesters
7a
r,ω-Dicarboxylic Acids. Carboxylic acids are generally more
reactive than their esters. Thus, they can be preferred to the latter
for polycondensation reactions. To this end, dimethyl-1,19-
nonadecanedioate and diethyl-1,23-tricosanedioate were both
hydrolyzed to the corresponding acids using potassium hydro-
are remarkably enhanced. Even for the relatively short chain
hexanediol the long chain of the diacid component dominates the
thermal properties. Accordingly, wide-angle X-ray scattering
(WAXS) essentially yields the reflexes of the polyethylene portion
of the material. For poly[1,6-hexadiyl-1,19-nonadecanedioate], for
example, a degree of crystallinity of about χ 68% was found
(Figure 4). These findings point out that high melting and crystal-
lization points, and crystallinity, can be obtained with a large
range of shorter chain diols, which can be based on either
petrochemical or renewable resources.
1
6
xide in methanol at elevated temperatures (T = 70 °C).
Recrystallization from toluene affords the long-chain R,ω-diacids
in more than 99% purity, as revealed by NMR spectroscopy.
r,ω-Diamines. Nonadecane-1,19-diamine and tricosane-
1
,23-diamine were prepared from the corresponding alcohols
4
161
dx.doi.org/10.1021/ma200627e |Macromolecules 2011, 44, 4159–4166

Macromolecules
ARTICLE
’
EXPERIMENTAL SECTION
Materials and General Considerations. Unless stated other-
wise, all manipulations were carried out under inert gas atmosphere
using standard Schlenk or glovebox techniques. Methanol and ethanol
were distilled from magnesium turnings and iodine. Methylene chloride,
2
dimethylformamide, and pentane were distilled from CaH and stored
under argon. Diethyl ether and THF were distilled from sodium/
benzophenone under inert conditions. All other solvents were used in
technical grade as received. Carbon monoxide (3.7) and hydrogen (5.0)
were supplied by Air Liquide. Methyl oleate (99%) was supplied by
Sigma Aldrich, technical grade methyl oleate (75%) by ABCR, and
ethyl erucate (95%) by TCI. All solvents were degassed by three
freezeꢀpumpꢀthaw cycles prior to use. Methanesulfonic acid (98%),
hydrogen chloride solution (2.0 M in diethyl ether), potassium hydro-
xide (90%), sodium methoxide (95%), triethylamine (99%), methane
sulfonyl chloride (g98%), sodium azide, 1,6-hexanediol (g99%),
Figure 4. WAXS diffraction pattern of poly[1,6-hexadiyl-1,19-non-
adecanedioate].
Polyamides. Polyamides were generated by polycondensa-
tion of the novel long-chain R,ω-diamines with the C and C ,
1
9
23
1
1
,12-dodecanediol (99%), and titanium(IV) butoxide (g97%) were
respectively, R,ω-dicarboxylic acids. H NMR spectroscopic
supplied by Sigma Aldrich. Silver triflate (99%) and 1,2-bis(di-tert-
butyl-phosphinomethyl)benzene (98%) were purchased from ABCR,
andpalladium/charcoalactivated(10%Pd) andpalladium(II) chloridefrom
Merck. Bis(dibenzylideneacetone)palladium(0) was purchased from
MCAT, Konstanz, Germany, and palladium(II) acetate was from
Umicore. All deuterated solvents were supplied by Eurisotop. NMR
spectra were recorded on a Varian Inova 400, a Bruker Avance 400 and
analyses of end groups on polymer solutions in C D Cl and
2
2
4
4
ꢀ1
phenol at 120 °C revealed molecular weights of M 10 g mol
.
n
It has been well documented that, due to the prevalence of
hydrogen bonding in polyamides, their melting and crystalliza-
tion temperatures overall tend to decrease with increasing chain
17
lengths of the monomers. Polyamides 23,19 and 23,23, based
on 1,23-tricosanediamine, exhibit a T 156 °C (T 132 °C; ΔH
1
13
m
c
m
ꢀ
1
ꢀ1
on a Bruker Avance DRX 600 spectrometer. H and C chemical shifts
were referenced to the solvent signals. High-temperature NMR mea-
8
5 J g ) and T 152 °C (T 130 °C; ΔH 88 J g ), respectively.
m
c
m
For polyamides 11,23 and 12,23, respectively, from polyconden-
sation of the shorter chain 1,11-diaminoundecane or 1,12-
diaminododecane with 1,23-tricosanedicarboxylic acid, as ex-
surements of polymers were performed in 1,1,2,2-tetrachloroethane-d
2
at 130 °C. For polyamides, phenol (ca. 20 vol %) was added to enhance
solubility. DSC analyses were performed on a Netzsch Phoenix 204 F1
pected, higher melting points were found, which amount to T
ꢀ1
m
instrument with a heating and cooling rate, respectively, of 10 K min
Data reported are from second heating cycles.
Dichloro{1,2-bis(di-tert-butylphosphinomethyl)benzene}-
.
ꢀ
1
1
67 °C (T 150 °C; ΔH 111 J g ) and T 168 °C (T 150 °C;
c
m
m
c
ꢀ
1
ΔH 121 J g ).
m
1
8,19
palladium(II) [(dtbpx)PdCl2].
Pd(dba) (138 mg, 0.24 mmol)
2
was added to a stirred solution of dtbpx (95 mg, 0.24 mmol) in THF
(6 mL). After 2 days the orange-red solution was filtered and the solvent
removed in vacuo. The resulting orange solid was dissolved in diethyl
ether (4 mL), and HCl (0.2 mL of a 2 M solution in diethyl ether) was
added to form the desired product as a yellow solid. After stirring for 1 h,
the product was filtered off and washed with diethyl ether (3 ꢁ 5 mL) and
THF (1 ꢁ 5 mL). After the product was dissolved in methylene chloride
and insoluble solids were filtered off, the desired product was precipitated
by slow addition of diethyl ether (93 mg, 68%).
’
SUMMARY AND CONCLUSIONS
Isomerizing alkoxycarbonylation is a unique reaction in that it
converts an internal double bond deep in the alkyl chain of an
unsaturated fatty acid into a terminal ester moiety highly
selectively. This was applied here to methyl oleate and ethyl
erucate as two readily available substrates. The resulting odd
carbon-numbered R,ω-diesters were generated on a scale of ca.
2
5 g per experiment routinely in polycondensation grade purity
(>99%), employing a 300 mL laboratory scale pressure reactor.
There are no evident limitations to further upscaling of this
reaction. These C19 and C23 R,ω-diesters, which hereby are
accessible for the first time in a practicable fashion, provide an
entry to a range of novel long-chain R,ω-difunctional com-
pounds. These can serve, among others, as monomers for novel
polycondensates. The dicarboxylic acids, as well as the diols were
generated in high yield and high purity employing low-cost
reagents. The C19 and C23 R,ω-diamines were prepared in this
work in a three-step route. Polyesters with long-chain C19 and
C23 dicarboxylate components exhibit melting points in the
general range of thermoplastic materials also with short chain
diol components, due to the crystallinity imparted by the
dicarboxylate-substituted long-chain methylene segments. Evi-
dent issues of future interest are an understanding and further
improvement of catalyst performance in the isomerizing alkox-
ycarbonylation, enhanced polymer molecular weights, and the
mechanical and processing properties as well as biodegradation
rates of the polycondensates reported here and other materials
from these monomers.
1
H NMR (CD Cl , 25 °C, 400 MHz): δ 7.45ꢀ7.33 (m, 2H, H-6),
2
2
3
7
3
.30ꢀ7.18 (m, 2H, H-5), 3.69ꢀ3.26 (m, 4H, H-3), 1.61 (d, JPH = 14.0,
31 13
2
6H, H-1). P NMR (CD
Cl
2
, 25 °C, 162 MHz): δ 36.75 (s).
C
NMR (CD Cl , 25 °C, 101 MHz): δ 135.49ꢀ135.39 (m, C-4),
2
2
133.56ꢀ133.40 (m, C-5), 127.92 (br s, C-6), 41.70ꢀ41.38 (m, C-2),
3
2.31 (br s, C-1), 30.18ꢀ29.96 (m, C-3).
Anal. Calcd. (%) for C24 Pd (571.88 g mol ): C 50.41, H
.76. Found: C 50.76, H 7.58
Bis(trifluoromethanesulfonato){1,2-bis(di-tert-butylpho-
sphinomethyl)benzene)}palladium(II) [(dtbpx)Pd(OTf)]-
ꢀ1
44 l2 2
H C P
7
1
4
[OTf] (1). AgOTf (82 mg, 0.32 mmol) was added to a solution of
[(dtbpx)PdCl ] (92 mg, 0.16 mmol) in methylene chloride (6 mL). The
orange reaction mixture was stirred overnight at room temperature
under the exclusion of light. After the insoluble AgCl was filtered off and
2
4
162
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Macromolecules
ARTICLE
Table 2. Details of the Crystal Structure Determination of 1
Table 3. Selected Bond Distances (Å) and Angles (deg) for 1
formula
C
25
H
44
O
3
F
3
P
2
SPd, CO
3
F
3
S
Pd1ꢀP1
2.2607(6)
2.2808(6)
2.2327(18)
2.2888(18)
99.30(2)
CCDC no.
formula weight, g mol
cryst. size, mm
space group
a, Å
817578
799.07
Pd1ꢀP2
ꢀ
1
Pd1ꢀO1
Pd1ꢀO2
P1ꢀPd1ꢀP2
O1ꢀPd1ꢀO2
O1ꢀPd1ꢀP1
O2ꢀPd1ꢀP2
0.45 ꢁ 0.32 ꢁ 0.21
P21/21/21
9.1472(3)
11.3899(5)
32.6773(10)
90, 90, 90
3404.5(2)
4
62.96(7)
b, Å
96.71(5)
c, Å
101.15(5)
R, β, γ deg.
3
V, Å
(0 0.321 0.330) (0 2.718 ꢀ0.331), as determined by the Platon TwinRot-
22
Mat procedure, was employed by which the BASF parameter refined to
Z
ꢀ
3
0.001 38. The weighted R factor (wR) and the goodness of fit S are based on
F ; the conventional R factor (R) is based on F. All non-hydrogen atoms
were refined with anisotropic displacement parameters. All scattering factors
and anomalous dispersion factors are provided by the SHELXL-97 program.
Hydrogen atoms were treated in a riding model. Thermal ellipsoid
representations were created with ORTEP-3. The complete X-ray analysis
is deposited as CCDC-817578. Data are given in Tables 2 and 3.
Alkoxycarbonylations. Alkoxycarbonylations of unsaturated long-
chain fatty acids esters were carried out in a mechanically stirred 300 mL
stainless steel pressure reactor with a glass inlay, equipped with a heating/
cooling jacket supplied by a thermostat controlled by a thermocouple
dipping into the reaction mixture. Prior to alkoxycarbonylation experi-
ments the reactor was heated to 30 °C and was then evacuated and purged
with nitrogen several times.
δcalc, g cm
1.559
2
T, K
100
ꢀ
1
μ, mm
0.831
F(000)
max, deg.
1640
23
Θ
27.96
no. of rflns measd.
no. of unique rflns
43569
8123
no. of rflns I > 2σ(I)
7865
a
1
R , I > 2σ(I)
0.0253
R
1
, all data
0.0290
a
wR
2
0.0607
ꢀ
3
diff. Fourier peak min./ max., e Å
ꢀ0.703/0.581
ꢀ F
a
2
2 2
2 2 1/2
R
1
= Σ F
o
ꢀ F
c
Σ|F
o
|, wR
2
= [Σ(w(F
o
c
) )/Σ(w(F
o
) )]
.
Methoxycarbonylation of Methyl Oleate with the in Situ Catalyst
System at a Substrate to Catalyst Ratio of 125. PdCl (136 mg, 0.768
2
the solvent was removed in vacuo, a dark yellow solid was obtained,
which was washed with diethyl ether until the filtrate was clear. The
crude product was dissolved in methylene chloride and subsequently
precipitated by slow addition of diethyl ether. After removal of solvent
residues in vacuo, 1 was obtained as an orange powder (93 mg, 73%).
Crystals suited for X-ray diffraction were grown from methylene
chloride layered with pentane.
mmol) was weighed into a Schlenk tube under air, and introduced into a
glovebox, where dtbpx (1.5 g, 3.84 mmol) was added. After the Schlenk
tube was removed from the glovebox 160 mL of methanol, methyl oleate
(32.6 mL of 75% methyl oleate), and methanesulfonic acid (0.5 mL, 7.68
mmol) were added. The reaction mixture was stirred for a few minutes, and
then cannula transferred into the pressure reactor. The reactor was closed,
pressurized with 20 bar carbon monoxide, and then slowly heated to 90 °C.
After 22 h the reactor was cooled to room temperature and vented. The
crude product was dissolved in methylene chloride and filtrated over a
Buchner funnel to remove solid residues. Removing the solvent in vacuo
and recrystallization from methanol yielded dimethyl-1,19-nonadecanedio-
ate (18.1 g, 71%).
1
H NMR (CD Cl , 25 °C, 400 MHz): δ 7.48ꢀ7.42 (m, 2H, H-6),
2
2
3
7
3
.38ꢀ7.32 (m, 2H, H-5), 3.84 (br s, 4H, H-3), 1.58 (d, JPH = 15.5 Hz,
31 13
2
6H, H-1). P NMR (CD
Cl
2
, 25 °C, 162 MHz): δ 79.12 (s).
C
NMR (CD Cl , 25 °C, 101 MHz): δ 133.39ꢀ133.25 (m, C-4),
2
2
1
1
31.67ꢀ135.51 (m, C-5), 129.11 (br s, C-6), 120.21 (q, JCF = 318.3
Hz CF
), 43.48ꢀ43.00 (m, C-2), 31.06 (br s, C-1), 27.1ꢀ26.70 (m,
1
3
9
H NMR (CDCl , 25 °C, 400 MHz): δ 3.66 (s, 6H, H-1), 2.30
3
1
3
C-3). F NMR (CD
2
Cl
2
, 25 °C, 376 MHz): δ ꢀ77.62 (s).
(t, J
= 7.6 Hz, 4H, H-3), 1.66ꢀ1.58 (m, 4H, H-4), 1.35ꢀ1.20 (m,
HꢀH
13
X-ray Diffraction Analysis of Complex 1 : Data are given in
Tables 2 and 3. The data collection was performed at 100 K on a STOE
IPDS-II diffractometer equipped with a graphite-monochromated radia-
tion source (λ = 0.710 73 Å) and an image plate detection system. A crystal
mounted on a fine glass fiber with silicon grease was employed. The
selection, integration, and averaging procedure of the measured reflex
intensities, the determination of the unit cell dimensions by a least-squares
fit of the 2Θ values, data reduction, LP-correction, and space group
determination were performed using the X-Area software package delivered
3
26H, H-5). C NMR (CDCl , 25 °C, 101 MHz): δ 174.48 (s, C-2),
51.56 (s, C-1), 34.28 (s, C-3), 30.16ꢀ29.15 (C-5), 25.12 (s, C-4).
Ethoxycarbonylation of Ethyl Erucate with the in Situ Catalyst
System at a Substrate to Catalyst Ratio of 125. PdCl (136 mg, 0.768
mmol) was weighed into a Schlenk tube under air and then introduced into
2
a glovebox, where dtbpx (1.5 g, 3.84 mmol) was added. After the Schlenk
tube was removed from the glovebox, 160 mL of ethanol, ethyl erucate
(40.4 mL of 95% ethyl erucate), and methanesulfonic acid (0.5 mL, 7.68
mmol) were added. The reaction mixture was stirred for a few minutes and
then cannula transferred into the pressure reactor. The reactor was closed,
pressurized with 20 bar carbon monoxide and then slowly heated to 90 °C.
After 22 h the reactor was cooled to room temperature and vented. The
crude product was dissolved in methylene chloride and filtrated over a
Buchner funnel to remove solid residues. Removing the solvent in vacuo
20
with the diffractometer. A semiempirical absorption correction was
performed. The structure was solved by Patterson methods (SHELXS-
9
7), completed with difference Fourier syntheses and refined with full-matrix
2
2 2 21
least-squares using SHELXL-97 minimizing w(F
parameter indicated twinning of the crystal. Therefore, a twin law (ꢀ1 0 0)
o
c
ꢀ F ) . The Flack-
4
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ARTICLE
and recrystallization from ethanol yielded diethyl-1,23-tricosanedioate
experiment the reactor was purged several times with argon. Dimethyl-1,19-
nonadecanedioate (16.8 mmol, 6.0 g) was weighed under air into a dry Schlenk
tube equipped with a magnetic stirring bar, which was then purged several times
with argon. Dry and degassed THF (40 mL) was added using standard Schlenk
techniques. Vigorous stirring afforded a homogeneous reaction mixture. In the
glovebox dichlorobis[2-(diphenylphosphino)ethylamine]ruthenium (16.8
μmol, 10 mg) and sodium methanolate (1.10 mmol, 60 mg) were weighed
into a second dry Schlenk equipped with a magnetic stirring bar. After the
Schlenk tube was removed from the glovebox, 40 mL of dry and degassed THF
was added. Both mixtures were then cannula-transferred into the reactor in an
argon counter stream. The reactor was closed, pressurized with 50 bar
hydrogen and then heated to 100 °C for 22 h. After cooling to room
temperature, the reactor was vented. The reaction mixture was retrieved from
thereactorandheatedtoaround50°C to remove catalyst residues by filtration
over a Buchner funnel. Removing the solvent in vacuo and recrystallization
from chloroform yielded nonadecane-1,19-diol (4.2 g, 83%).
(30.6 g; 76%).
1
3
H NMR (CDCl , 25 °C, 400 MHz) δ 4.12 (q, J
= 7.1 Hz, 6H,
3
HꢀH
3
H-2), 2.28 (t, JHꢀH = 7.6, 4H, H-4), 1.65ꢀ1.57 (m, 4H, H-5), 1.3ꢀ1.18
13
(
3
m, 38H, H-1/H-6). C NMR (CDCl , 25 °C, 101 MHz): δ 174.08 (s,
C-3), 60.28 (s, C-2), 34.54 (s, C-4), 29.94ꢀ29.22 (C-6), 25.14 (s, C-5),
1
4.40 (s, C-1).
Alkoxycarbonylation of Methyl Oleate with the Defined Catalyst
Precursor [(dtbpx)Pd(OTf)](OTf) (1) at a Substrate to Catalyst Ratio of
500. [(dtbpx)Pd(OTf)](OTf) (1) (153 mg, 0.192 mmol) was weighed
into a Schlenk tube under an inert atmosphere and dissolved in 160 mL of
methanol. Methyl oleate (32.6 mL of 75% methyl oleate) was added.
After stirring for a few minutes, the reaction mixture was cannula
transferred into the pressure reactor. The reactor was closed, pressurized
with 20 bar carbon monoxide and then slowly heated to 90 °C. After 22 h
the reactor was cooled to room temperature and vented. The crude
product was dissolved in methylene chloride and filtrated over a Buchner
funnel to remove solid residues. Removing the solvent in vacuo and
recrystallization from methanol yielded dimethyl-1,19-nonadecanedioate
1
3
H NMR (C
2 2 4
D Cl , 130 °C, 600 MHz): δ 3.58 (t, JHꢀH = 6.5 Hz, 4H,
1
4
-H), 1.58ꢀ1.49 (m, 4H, 2-H), 1.38ꢀ1.21 (m, 30H, 3-H), 1.02 (br s, 2H,
13
(9.0 g, 35%).
2 2 4
-H). C NMR (C D Cl , 130 °C, 150 MHz): δ 63.17 (C-1), 33.15 (C-2),
0
Nonadecane-1,19-dicarboxylic Acid. In a round bottomed flask
29.78ꢀ29.50 (C-3), 25.99 (C-3 ).
dimethyl-1,19-nonadecanedioate (11.2 mmol, 4.0 g) was suspended in
methanol (30 mL) and heated to 70 °C. To this solution was slowly added
KOH (70.2 mmol, 4.0 g). The resulting mixture was then refluxed for 2 h
during which more methanol (30 mL) was added. After further addition of
KOH (62.4 mmol, 3.5 g) the mixture was refluxed for another 8 h. Cooling
the suspension to room temperature and removing the solvent in vacuo
afforded a white solid, which was suspended in water (60 mL). The
suspension was acidified to pH = 2 by adding 3 N hydrochloric acid. The
dicarboxylic acid was then filteredoff, washed with water, and recrystallized
from toluene to give a glittery white solid in 98% yield (3.6 g).
Tricosane-1,23-diol. The reduction of diethyl-1,23-tricosanedioate
was carried out analogously to the procedure described above for its 1,19-
analgoue. After the reaction mixture was retrieved from the reactor, it was
heated to around 50 °C and then filtrated over a Buchner funnel to remove
catalyst residues. THF was removed in vacuo. Tricosane-1,23-diol was
recrystallized from chloroform to obtain 78% yield (4.6 g).
1
3
H NMR (C D Cl , 130 °C, 600 MHz): δ 3.59 (t, J = 6.5 Hz, 4H,
HꢀH
2
2
4
1
4
2
-H), 1.60ꢀ1.48 (m, 4H, 2-H), 1.40ꢀ1.20 (m, 40H, 3-H), 1.02 (br s, 2H,
13
2 2 4
-H). C NMR(C D Cl , 130°C, 150 MHz): δ63.18 (C-1), 33.15 (C-2),
0
9.79ꢀ29.50 (C-3), 25.99 (C-3 ).
Nonadecane-1,19-dimesylate. In a 100 mL two-necked round
1
H NMR (dmso-d , 130 °C, 600 MHz): δ 11.19 (br s, 2H, 5-H), 2.19
6
bottomed flask nonadecane-1,19-diol (10.0 mmol, 3.0 g) and triethylamine
50 mmol, 5.1 g) were dissolved in THF (40 mL) at 50 °C. To this solution
was slowly added mesyl chloride (34 mmol, 3.9 g) via a syringe. The resulting
yellow suspension was stirred for 3 h until it turned red. After addition of
dichloromethane (150 mL), the reaction mixture was successively washed
with water (100 mL), 2 M HCl (100 mL), water (100 mL), saturated
3
(
2
3
t, JHꢀH = 7.3 Hz, 4H, 2-H), 1.58ꢀ1.52 (m, 4H, 3-H), 1.35ꢀ1.25 (m,
(
13
6H, 4-H). C NMR (dmso-d , 130 °C, 150 MHz): δ 173.22 (C-1),
6
3.16 (C-2), 28.36ꢀ27.83 (C-4), 23.86 (C-3).
Tricosane-1,23-dicarboxylic Acid. Tricosane-1,23-dicarboxylic
acid was prepared according to the procedure described above for its
shorter chain analogue. Recrystallization from toluene yielded tricosane-
NaHCO solution (80 mL), and water 100 mL). The organic phase was
3
1,23-dicarboxylic acid (4.1 g, 96%).
dried with MgSO , and the solvent was removed in vacuo. After recrystalliza-
4
tion from ethanol, nonadecane-1,19-dimesylate (8.7 mmol, 87%) was
obtained as a gleaming white solid.
1
H NMR (dmso-d , 130 °C, 600 MHz): δ 11.34 (br s, 2H, 5-H), 2.41
6
3
(
3
3
t, JHꢀH = 7.2 Hz, 4H, 2-H), 1.59ꢀ1.51 (m, 4H, 3-H), 1.36ꢀ1.21 (m,
13
1
3
4H, 4-H). C NMR (dmso-d , 130 °C, 150 MHz): δ 173.18 (C-1),
H NMR (CDCl , 25 °C, 400 Hz): δ 4.22 (t, J
= 6.6 Hz,
HꢀH
6
3
3.13 (C-2), 28.30ꢀ27.82 (C-4), 23.85 (C-3).
4H, 1-H), 2.99 (s, 6H, 4-H), 1.82ꢀ1.63 (m, 4H, 2-H), 1.42ꢀ1.20
Nonadecane-1,19-diol. The reduction was carried out, analogous to a
(m, 30H, 4-H).
15
reported procedure, in a 300 mL stainless steel mechanically stirred pressure
reactor equipped with a heating jacket and a glass inlay. Prior to the reduction
Tricosane-1,23-dimesylate. Tricosane-1,23-dimesylate was pre-
pared analogous to its 1,19-analogue. The organic phase was dried with
4
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Macromolecules
MgSO , and the solvent was removed in vacuo. After recrystallization
from ethanol, tricosane-1,23-dimesylate (8.7 mmol, 87%) was obtained
as a gleaming white solid.
ARTICLE
4
(dmso-d
(C-4), 25.69 (C-4 ).
6
, 130 °C, 101 MHz): δ 40.82 (C-1), 32.33 (C-2), 28.36ꢀ28.07
0
Tricosane-1,23-diamine. Hydrogenation of tricosane-1,23-diazide
was carried out analogous to the aforementioned procedure. Tricosane-
1,23-diamine was isolated as an off-white solid that was recrystallized from
ethanol to give the desired product in 82% yield.
1
3
H NMR (CDCl
3
, 25 °C, 400 MHz): δ 4.22 (t, JHꢀH = 6.6 Hz, 4H,
1
-H), 3.00 (s, 6H, 4-H), 1.80ꢀ1.69 (m, 4H, 2-H), 1.46ꢀ1.18 (m, 38H,
4
-H).
1
3
Nonadecane-1,19-diazide. In a round bottomed flask nonade-
H NMR (dmso-d , 130 °C, 400 MHz): 2.59 (t, J
HꢀH
= 6.5 Hz, 4H,
6
13
cane-1,19-dimesylate (8.0 mmol, 3.7 g) was dissolved in DMF (60 mL)
at 65 °C. To this solution was added sodium azide (40 mmol, 2.6 g). The
resulting mixture was stirred at 85 °C for 4 h. After cooling, the
suspension water (50 mL) was added. The DMFꢀwater phase was
extracted with hexane twice. The organic layer was successively washed
1-H), 1.41ꢀ1.34 (m, 4H, 2-H), 1.33ꢀ1.27 (m, 38H, 4-H). C NMR
(dmso-d , 130 °C, 101 MHz): δ 40.88 (C-1), 32.51 (C-2), 28.38ꢀ27.98
6
0
(C-4), 25.70 (C-4 ).
Polymerization Experiments. Polyesters. Polyesters were pre-
pared in a 100 mL two-necked Schlenk tube equipped with an
overhead stirrer. Efficient mixing of the highly viscous polymer melt
was achieved by a helical agitator. Under a static argon atmosphere the
monomers (2.8 mmol of dimethyl 1,19-nonadecanedioate or diethyl-
1,23-tricosanedioate, respectively, and 2.8 mmol of R,ω-diol) were
filled into the reaction vessel and molten by heating to 100 °C. A
with saturated NaHCO
3
solution (20 mL) and saturated NaCl solution
(20 mL). The organic layer was dried with MgSO and the solvent was
4
removed in vacuo to give the desired product as a white solid in
90% yield.
0
.4 mL aliquot of a 0.28 M titanium(IV) butoxide solution in toluene
was injected, and the temperature was raised to 180 °C over 2 h. In the
course of an additional 10 h the temperature was slowly increased to
2
20 °C. Finally, the polymer melt was stirred for about 2 h at this
temperature under reduced pressure (0.01 mbar). Poly[1,6-hexadiyl-
1
Poly[1,6-hexadiyl-1,19-nonadecanedioate]: T
ΔH
1
3
H NMR (CDCl , 25 °C, 400 MHz): δ 3.24 (t, J
= 7 Hz, 4H,
ꢀ1
3
HꢀH
,23-tricosanedioate]: Tm 92 °C, T 75 °C, and ΔHm 145 J g
.
c
1
-H), 1.66ꢀ1.53 (m, 4H, 2-H), 1.40ꢀ1.18 (m, 30H, 3-H).
m
86 °C, T 72 °C, and
c
Tricosane-1,23-diazide. Tricosane-1,23-diazide was prepared
ꢀ1
m
152 J g . Poly[1,12-dodecadiyl-1,23-tricosanedioate]: T
m
analogous to the aforementioned procedure. The desired product was
isolated as a white solid in 96% yield.
ꢀ1
1
00 °C, T
c
76 °C, and ΔH
m
156 J g . Poly[1,12-dodecadiyl-1,19-
ꢀ1
nonadecanedioate]: Tm 93 °C, T 76 °C, and ΔH 168 J g
.
c
m
Polyamides. Prior to all polymerization reactions the diamine salts
of the corresponding dicarboxylic acids were prepared to ensure an
exact stoichiometry of these two components. A 10% ethanolic
solution of the diamine (1.1 mmol) was slowly added to an equimolar
portion of a 10% ethanolic solution of the dicarboxylic acid (1.1 mmol)
at elevated temperature, resulting in precipitation of a white solid. The
mixture was refluxed for 0.5ꢀ1.5 h. After the suspension was cooled to
room temperature, the white solid was filtered off, washed with warm
ethanol, and dried in vacuo. A 100 mL two-necked Schlenk tube
equipped with an overhead stirrer with a helical agitator was charged
with the salt, and purged several times with argon. The temperature
was raised to 120 °C over 2 h. In the course of another 4 h the
temperature was slowly increased to 220 °C, and held for 2 h. Finally,
the polymer melt was stirred for about 15 h at this temperature under
reduced pressure (0.01 mbar).
1
3
H NMR (CDCl
3
, 25 °C, 400 MHz): δ 3.25 (t, JHꢀH = 7 Hz, 4H,
1
-H), 1.65ꢀ1.55 (m, 4H, 2-H), 1.42ꢀ1.20 (m, 38H, 3-H).
Nonadecane-1,19-diamine. Nonadecane-1,19-diazide (7.2
mmol, 2.5 g) and Pd/C (10 wt %) (250 mg, 0.23 mmol Pd) were
weighed under air into a dry Schlenk tube. In an argon counter stream
dry and degassed THF (70 mL) was added. The resulting mixture was
cannula-transferred into a 280 mL stainless steel mechanically stirred
(
1500 rpm) pressure reactor equipped with a glas inlay and a heating/
cooling jacket controlled by a thermocouple dipping into the reaction
mixture, which was purged several times with argon prior to the
reaction. The reactor was closed and pressurized with 20 bar hydrogen
and heated to 40 °C. After 3 h the reactor was cooled to room
temperature and vented. The reaction mixture was then filtrated
repeatedly over a B €u chner funnel at 50 °C to remove catalyst residues.
The solvent was removed in vacuo to afford an off-white solid, which
was recrystallized from ethanol to give the desired product in
’ ASSOCIATED CONTENT
S
Supporting Information. Cif file containing the X-ray
b
diffraction data of 1 (CCDC-817578). This material is available
free of charge via the Internet at http://pubs.acs.org.
8
3% yield.
’
AUTHOR INFORMATION
Corresponding Author
*
E-mail: stefan.mecking@uni-konstanz.de.
’
ACKNOWLEDGMENT
1
3
H NMR (dmso-d
6
, 130 °C, 400 MHz): 2.59 (t, JHꢀH = 6.5 Hz, 4H,
We thank Inigo G €o ttker-Schnetmann for X-ray diffraction
analyses of compound 1, and Elana Harbalik and Marina Krumova
1
3
1
-H), 1.41ꢀ1.34 (m, 4H, 2-H), 1.33ꢀ1.25 (m, 30H, 4-H). C NMR
4
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Macromolecules
ARTICLE
for WAXS analysis. NMR measurements by Anke Friemel and
Ulrich Haunz are acknowledged. S.M. is indebted to the Fonds der
Chemischen Industrie for financial support.
’
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