Incorporation of primary amines into a polyester chain by a combination of chemical and lipase-catalyzed ε-caprolactone ring-opening processes

Article abstract of DOI:10.1002/adsc.200600642

A simple chemoenzymatic strategy for the incorporation of bioactive and suitably functionalized molecules into a polyester chain has been developed. The protocol involves first the reaction of a primary amine with ε-caprolactone to give an amide carrying a terminal primary hydroxy group, followed by the enzymatic growth of the polymeric chain triggered by Novozym 435. This method is versatile and easy to handle and is suitable for the incorporationof different amines into polyesters, as has been shown with the model compounds benzylamine and tryptamine, the bioactive compound N-deacetylthiocolchicine and the functionalized propargylamine and tyramine .

Full text of DOI:10.1002/adsc.200600642

FULL PAPERS
DOI: 10.1002/adsc.200600642
Incorporation of Primary Amines into a Polyester Chain by a
Combination of Chemical and Lipase-Catalyzed e-Caprolactone
Ring-Opening Processes
a,b
c
b,
a
Mattia Marzorati, Karl Hult, Sergio Riva, * and Bruno Danieli
a
Dipartimento di Chimica Organica e Industriale, Università degli Studi di Milano, Via Venezian 21, 20133 Milano, Italy
Istituto di Chimica del Riconoscimento Molecolare, C.N.R., Via Mario Bianco 9, 20131 Milano, Italy
Fax : (+39)-02-2890-1239; e-mail: sergio.riva@icrm.cnr.it
b
c
Department of Biochemistry, Royal Institute of Technology, Stockholm, 10691 Sweden
Received: December 19, 2006; Revised: June 1, 2007
Supporting information for this article is available on the WWW under http://asc.wiley-vch.de/home/.
Abstract: A simple chemoenzymatic strategy for the of different amines into polyesters, as has been
incorporation of bioactive and suitably functional- shown with the model compounds benzylamine and
ized molecules into a polyester chain has been devel- tryptamine, the bioactive compound N-deacetylthio-
oped. The protocol involves first the reaction of a colchicine and the functionalized propargylamine
primary amine with e-caprolactone to give an amide and tyramine .
carrying a terminal primary hydroxy group, followed
by the enzymatic growth of the polymeric chain trig- Keywords: amines; Candida antarctica lipase; e-cap-
gered by Novozym 435. This method is versatile and rolactone; enzyme catalysis; Novozym 435; ring-
easy to handle and is suitable for the incorporation opening polymerization
Introduction
has been previously chosen by us as a model target
[5,10,11]
molecule for successful biotransformations,
and,
Enzyme-catalyzed polymerizations of suitable reac- specifically, we have shown that the sugar moiety of 1
tive monomers is an expanding area of applied bioca- could be regioselectively acylated at its primary OH
[1–3]
talysis.
Specifically, enzyme-catalyzed ring-opening with short chain aliphatic acids by proteases and lipas-
polymerization (eROP) has proved to be an efficient es (and specifically, among the latter enzymes, by No-
[
10,11]
tool for the preparation of terminally functionalized vozym 435)
and block polyesters with low PDI values. Several
in organic solvents.
[
4]
As will be described in the following, the glucoside
examples have been reported in the literature so far, 1 could be incorporated into the polymeric product,
most of them exploiting the peculiar performances of but the results were not fully satisfactory. However, in
the immobilized lipase B from Candida antarctica spite of these initial data, we thought that the thiocol-
[
1,2]
(
Novozym 435).
In the context of our ongoing research activity fi- lymer by exploiting the reactivity of functional groups
nalized to the biocatalyzed modification of natural different from the OHs at the sugar moiety, namely
chicinoid moiety could be included into a growing po-
[5]
products, we became interested in a series of papers the C-7-NH of N-deacetylthiocolchicine (2), an easily
2
describing the regioselective lipase-catalyzed e-capro- accessible derivative of 1.
lactone (e-CL) eROP initiated by simple alkyl gluco-
The general outcome of these experiments was the
[6,7]
pyranosides.
We were attracted by this approach as development of a combination of simple chemical and
a tool to obtain the “macromolecularization” of natu- enzymatic processes for the incorporation of suitably
ral products, with the opportunity to confer either a functionalized molecules into a polyester chain. These
hydrophobic or a hydrophilic character to these com- results offer new opportunities to the preparation of
pounds, depending on the lactone used in the eROP end-functionalized polyesters that, in turn, can be
process (i.e., e-caprolactone or 1,5-dioxepan-2-one).
Thiocolchicoside (1, 3-O-b-d-glucopyranosyl-3-O- mers.
demethylthiocolchicine) is a synthetic derivative of
used for the preparation of suitable block copoly-
[
12]
[
8,9]
the naturally occuring compound colchicoside.
It
Adv. Synth. Catal. 2007, 349, 1963 – 1968
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1963

Mattia Marzorati et al.
FULL PAPERS
Results and Discussion
[
6,7]
Following standard protocols,
the Novozym 435-
catalyzed e-CL-ROP initiated by the model glucoside
thiocolchicoside (1) was performed, furnishing a
1
yellow polymeric mixture 1a. The H NMR analysis
of the isolated product showed that 1 was indeed in-
corporated into the macromolecular product, but the
percentage of thiocolchicoside-initiated polyesters 1a
in the obtained polymeric mixture was unsatisfactory,
due to the presence of significant amounts of water-
Scheme 1. Chemoenzymatic e-caprolactone ring-opening
polymerization.
[
13]
initiated poly e-CL. Our attempts to decrease the
water competition resulted in a slightly increase of
the percentage of 1a in the polyester product mixture, and triptamine (4) – as well as two functionalized
percentage that, however, did never exceeded 50% amines – propargylamine (5) and tyramine (6) – were
(
see the NMR spectra in the Supporting Information). efficiently incorporated into the polyesters obtained
Apparently, despite our attempts, we were not able to by the biocatalyzed e-CL-ROP. On the contrary, sec-
completely eliminate water from the reaction mixture, ondary amines (like, for instance, N-benzyl-N-methyl-
and water proved to be a much better (and natural) amine, 7) could not be efficiently incorporated using
nucleophile for the intermediate acyl-enzyme than the same protocol.
the primary sugar OH of the bulky thiocolchicoside.
According to Scheme 1, the intermediate hydroxy
Pursuing our goal to introduce the pharmacologi- amides 2a–6a were easily prepared (by heating the
cally valuable thiocolchicine moiety into a polyester corresponding amines 2–6 in the presence of an
chain, we turned our attention to the cognate deriva- excess – typically 40 equivs. – of e-CL at 708C for
tive N-deacetylthiocolchicine (2), with the hope that 2 h), and isolated to be characterized. In the complete
the primary amino group at C-7 of this molecule chemoenzymatic processes, compounds 2a–6a were
could be a better initiator than the sugar hydroxy not isolated and the enzymatic ROPs were started by
groups of 1.
adding, after 2 h, a suitable amount of Novozym 435
Despite the fact that it is well-known that lipase to the reaction mixture. The reactions were left over-
[
14]
can also catalyze the formation of amide bonds, to night at 608C, and the monomer conversion was eval-
1
the best of our knowledge and to our surprise, the use uated by H NMR analysis of the crude reaction mix-
of amines as initiators in an enzymatic-catalyzed e-CL tures. The polyesters 2b–6b were isolated following
ROP has been only described once in the literature, usual work-up protocols and characterized. Some of
[
15]
by Gross and co-workers. The goal of their study the relevant data are reported in Table 1.
was not synthetic but mechanicistic, and was finalized
to the comparison of the performances of an amine
(
butylamine) and of the corresponding alcohol (buta- Table 1. Incorporation of amines into poly e-CL obtained by
[a]
chemoenzymatic ROP.
Amine Conver- Incor-
nol) in order to get information on the effect of the
initiator on the product structure, propagation kinet-
ics and mechanism of the enzymatic polymerization.
After some experimentation (for details see Sup-
porting Information), we came to the conclusion that
[
d]
[e]
[e]
[e]
DP Mn
Mw
PDI
[b]
[c]
sion
%]
poration
[%]
[
2
3
4
5
6
>95
>95
>95
>95
>95
>95
85
85
90
85
40
37
37
38
38
6,850 12,250 1.79
8,050 14,500 1.80
7,400 13,500 1.82
8,150 14,600 1.79
8,100 14,500 1.79
2
was also a poor substrate for Candida antarctica
lipase, probably due to steric reasons. However, the
nucleophilicity of the C-7 amino group allowed 2 to
be acylated in the presence of a suitable reactive
ester, even in the absence of the enzyme. We rea-
[
16]
[a]
soned that the cyclic e-CL, due to its ring strain,
Reaction conditions: monomer e-caprolactone (M) to
amine (A) molar feed ratio, 40:1; temperature, 608C.
Monomer conversion determined by H NMR spectros-
copy of the crude reaction mixture.
Percentage of amino incorporation into the polyester de-
could be assimilated to an activated acyl donor when
suffering the attack of a primary amino group, like
that present in 2. In this way a new compound (2a)
carrying a terminal, more accessible primary OH
could be formed in situ. This adduct, in turn, could
act as a more efficient initiatior for the lipase-cata-
lyzed e-CL-ROP (Scheme 1).
[
[
b]
c]
1
1
termined by H NMR spectroscopy of the precipitated
polymer.
[d]
1
Determined by H NMR spectroscopy of the precipitated
polymer.
[e]
Confirming this hypothesis, compound 2 and also
Obtained by SEC analysis in comparison with polystyr-
ene standards (detector, RI).
two other model primary amines – benzylamine (3)
1964
asc.wiley-vch.de
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2007, 349, 1963 – 1968

Incorporation of Primary Amines into a Polyester Chain
FULL PAPERS
1
Figure 1. . H NMR spectra of compound 2a and of the polyester 2b.
1
As an example, Figure 1 shows the H NMR spectra polymer, which showed a Gaussian distribution of
of the adduct 2a and of the corresponding polyesters peaks separated by 114.14 Da (corresponding to one
mixture 2b. The incorporation of a 6-hydroxyhexanoyl e-CL unit). Besides that, the evaluation of the exact
moiety in 2a was clearly demonstrated by the triplet mass of some single peaks confirmed the incorpora-
at 3.64 (corresponding to the terminal CH OH of the tion of 2 into the polyester. For instance, the peak at
2
+
6
-hydroxyhexanoyl moiety partially overlapping the 1764.94223 Da corresponded to the Na adduct of 2b
OCH singlet due to the C-1 methoxy moiety). Addi- with n=12 (error 0.7 ppm), the one at 1879.00924 Da
tionally, the ratio between the integrated signals at corresponded to the Na adduct of 2b with n=13
3
+
3
.68–3.64 (a singlet due to a OCH moiety of 2 plus (error 0.1 ppm), etc.
3
the above described triplet) and at 4.68 ppm (a dt due
to H-7 of 2) was approximately 5, thus confirming the
ca. 1:1 ratio between the starting amine 2 and the Conclusions
added aliphatic chain. A similar ratio between the in-
tegration values of these signals in the polyester 2b We have shown that functionalized primary amines
confirmed the complete incorporation of the amine can be incorporated into a polyester chain by a com-
into the polyester product. The ratio between the bination of chemical and enzymatic processes, which
very intense signals at 4.08 (a triplet due to the “inter- involves first the reaction of an amine with e-CL to
nal” ÀCH OCOÀ esterified moieties) and at 3.68– form the corresponding w-hydroxy amides, followed
2
3.64 ppm (the above described triplet due to the ter- by the enzymatic growth of the polymeric chain trig-
minal CH OH and the singlet due to a OCH moiety) gered by Novozym 435.
2
3
allowed us also to estimate a degree of polymeri-
The suggested protocol is versatile, suitable for the
zation (DP) value of 40. The number average molecu- incorporation of different primary amines and easy to
lar weight (M ) and the weight average molecular handle (i.e., it does not require special apparatus, like
n
weight (M ) were determined by size exclusion chro- dry boxes, to keep the water content under control),
w
matography, which allowed us also to calculate a poly- therefore it might allow one to further extend the
[4]
dispersity value (PDI) of 1.79. Additional information available array of terminal-functionalized polymers.
was obtained by the high resolution ESI-MS of the Specifically, the functionalized polyesters 5b and 6b
Adv. Synth. Catal. 2007, 349, 1963 – 1968
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
1965

Mattia Marzorati et al.
FULL PAPERS
can be utilized for the preparation of different poly- (Magnex). Samples were dissolved in CH CN and injected
3
into the instrument equipped with its own ESI source. Spec-
tra were recorded in the HR mode with resolutions ranging
from 20,000 to 30,000.
mer architectures, exploiting either the so-called
[17]
“
click chemistry” or the radical polymerization of
[18]
phenols.
SEC: The molecular weight distribution (MWD) of poly-
mers were determined by a modular Alliance 2690 size ex-
clusion chromatography (SEC) system from Waters
equipped with a 2414 differential refractometer as on-line
concentration detector. The columns set was composed of
two PLGel Mixed C columns (300”7.8 mm, 5 mm of particle
size) from Polymer Laboratories. The experimental condi-
tions consisted of tetrahydrofuran as mobile phase stabilized
To our surprise, the well-known higher chemical re-
activity of amines, that, in contrast to alcohols or
thiols, make this functional group able to easily open
[
19–21]
an e-CL molecule,
has never been synthetically
exploited before for biocatalyzed polymerizations.
À1
with 0.05% of BHT, 358C of temperature, 0.8 mLmin of
Experimental Section
À1
flow rate, about 3 mgmL of sample concentration and
1
00 mL of injection volume. Narrow MWD polystyrene
Materials and Methods
standards were used for the calibration of the SEC system.
Empower chromatographic software from Waters was used
to process the data.
Thiocolchicoside (1; Figure 2) and thiocolchicine were a gift
from Indena S.p.A., Milano, Italy. N-Deacetylthiocolchicine
(
2; Figure 2) was simply prepared from thiocolchicine fol-
[22]
lowing a standard procedure.
Novozym 435 was a gift
Polymerization of e-CLin the Presence of
Thiocolchicoside (1) as an Initiator
from Novozymes Inc. The other substrates and reagents
were from Fluka. Tryptamine (4) was crystallized from pe-
troleum ether before use, while benzylamine (3) and e-cap-
rolactone were distilled (3, T=1858C at p=1 atm; e-capro-
lactone, T=988C at p=5 mm Hg). TLC analysis were per-
formed on silica plates (Merck 60 F254) and treated with the
Thiocolchicoside (1, 282 mg), the enzymatic preparation No-
vozym 435 (77 mg) and molecular sieves (150 mg) were
added to a two-necked, round-bottom flask and dried over-
night in a dessicator over P O . Freshly distilled e-caprolac-
2
5
molybdate reagent [(NH ) MoO ·4H O, 42 g ; Ce(SO ) ,
A
H
R
U
G
4
6
24
2
4 2
tone (2.2 mL) was added and the mixture was left at 608C
overnight. The crude reaction mixture was dissolved in 4 mL
of dioxane, the solid enzyme and the molecular sieves were
filtered. Addition of cold water to the solution caused the
precipitation of a yellow solid. After vacuum-drying, direct
NMR analysis of the crude sample showed that it was a mix-
ture of thiocolchicoside-initiated polyester 1a and water-ini-
2
g; H SO concentrated 62 mL; made up to 1 L with deion-
2 4
ized water]. Preparative TLC were performed on silica
plates (Merck 60, 230–400 mesh).
NMR Spectroscopy: The percentage of monomer (e-cap-
rolactone) conversion, the percentage of amine incorpora-
tion and the degree of polymerization were determined by
1
H NMR spectroscopy with a Bruker AC400 (400 MHz)
tiated polyester.
1
using CDCl as the solvent. Specifically, the monomer con-
3
The H NMR (ppm, CDCl ) spectrum is reported in the
3
version was evalated by comparing the area of the triplet
Supplementary Materials Section. d (polymer chain)=4.07
(t, J=6.8 Hz, CH -d); 3.65 (m, terminal CH OH, CH -e),
due to the CH OCO of e-caprolactone (resonating at
2
2
2
2
4.25 ppm) with that of the triplet due to the polymeric
2
.32 (t, J=7.2 Hz, CH -a), 1.67 (m, CH -b), 1.41 (m, H-c); d
2
2
CH OCO (resonating at 4.07 ppm).
2
(thiocolchicoside moiety, selected data)=7.25 and 7.05 (1H
each, AB system, J=10.5 Hz, H-11 and H-12), 7.22 (1H, s,
H-8), 6.8 (1H, s, H-4), 4.82 (1H, d, J=7.4 Hz, H-1’), 4.60
Mass Spectroscopy: High resolution electrospray mass
spectra (HR-ESI-MS) were acquired with an FT-ICR (Four-
TM
ier Transfer Ion Cyclotron Resonance) APEX II model
(
1H, dt, J =11.3 Hz, J =6.7 Hz, H-7), 4.50 (1H, dd, J =
1
2
1
(
Bruker Daltonics) equipped with a 4.7 Tesla cryo-magnet
1
2
3
2.0 Hz, J =5.1 Hz, H-6’ ), 4.42 (1H, dd, J =12.0 Hz, J =
2 a 1 2
.2 Hz, H-6’ ), 3.99 (3H, s, OCH ), 3.65 (m, OCH , H-2’, H-
b
3
3
’, H-4’), 2.45 (3H, s, SCH ); ESI-MS (selected data, Da):
3
+
m/z=1042.44874 (1a+Na , with n=5; calculated for
+
[
C H NO S(C H O ) Na] : 1042.44406), 1058.42216 (1a+
10 6 10 2 5
+
AHCTREUGN
A
H
R
U
G
2
+
7
33
K , with n=5; calculated [C H NO S(C H O ) K] :
10 6 10 2 5
+
1
2
7
33
058.41799), 1067.61738 (water-initiated poly e-CL+Na ,
+
with
n=9;
calculated
for
[H O(C H O ) +Na] :
6 10 2 9
+
A
H
R
U
G
2
1
067.61738), 1083.58988 (water-initiated poly e-CL+K ,
+
with
083.58644).
The integrated NMR signals indicated that the ratio be-
n=9;
calculated
for
[H O(C H O ) +K] :
A
H
R
U
G
2
6 10 2 9
1
tween thiocolchicoside-initiated polyester 1a and water-initi-
ated polyester was less than 1:1. This value was obtained by
comparing the integration value of the signal at 4.82 ppm
due to H-1’ (or of the signal at 4.60 due to H-7) with the in-
tegration value of the multiplet at 3.65 due to the overlap-
ping of the signals of one OCH , of the sugar protons H-2’,
3
H-3’, H-5’ and of the terminal oxymethylene of the polymer-
Figure 2. Compounds 1–1a.
ic chains.
1966
asc.wiley-vch.de
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2007, 349, 1963 – 1968

Incorporation of Primary Amines into a Polyester Chain
FULL PAPERS
Synthesis of 6-Hydroxyhexanoyl Amides (2a–6a;
Figure 3)
The primary amines (2–6, 0.1 mmol) and e-CL (4 mmol)
were added to a round-bottom flask. The flask was im-
mersed in an oil bath at 708C and the reaction was moni-
tored by TLC. After consumption of the amine (typically
2
h), the products were isolated by preparative TLC.
a: yellow solid; R =0.39 (eluent AcOEt : MeOH 10:1);
2
f
1
H NMR (ppm, CDCl , see Figure 1, selected data): d=7.43
3
(
1H, s, H-8), 7.35 (1H, d, J=10.4 Hz, H-11), 7.19 (1H, br d,
J=7.1 Hz, NH), 7.15 (1H, d, J=10 Hz, H-12), 6.56 (1H, s,
H-4), 4.68 (1H, dt, J =11.4 Hz, J =6.8 Hz, H-7), 3.96 (3H,
1
2
s, OCH ), 3.92 (3H, s, OCH ), 3.68 (3H, s, OCH ), 3.64
3
3
3
(
2H, t, J=6.1 Hz, CH OH, CH -a), 2.45 (3H, s, SCH ); ESI-
2 2 3
+
MS (Da): m/z=510.19240 (2a+Na , calculated for
+
+
[
C H NO S+Na] : 510.19208), 997.39418 (2”2a+Na ,
26 33 6
+
calculated for [C H N O S +Na] : 997.39494).
5
2
66
2
12 2
1
3
a: white solid; R =0.27 (eluent AcOEt); H NMR (ppm,
f
CDCl , the spectrum is depicted in the Supporting Informa-
3
tion): d=7.36–7,27 (5H, m, ArH), 4.44 (2H, d, J=5.7 Hz,
CH -1), 3.64 (2H, t, J=6.4 Hz, CH -e), 2.24 (2H, t, J=
2
2
7
.4 Hz, CH -a), 1.70 (2H, q, J=6.4 Hz, CH -b or CH -d)
2
2
2
and 1.59 (2H, q, J=6.4 Hz, CH -b or CH -d), 1.42 (2H, m,
2
2
+
CH -c); ESI-MS (Da): m/z=244.13052 (3a+Na , calculated
2
+
+
for [C H NO +Na] : 244.13080), 465.27315 (2”3a+Na ,
calculated for [C H N O +Na] : 465.27238).
13
19
2
+
26
38
2
4
4
a: white solid; R =0.12 (eluent AcOEt); H NMR (ppm,
f
CDCl , the spectrum is depicted in the Supporting Informa-
3
tion): d (aromatic protons)=7.62 (1H, d, J=8.0 Hz), 7.40
(
8
1H, d, J=8.0 Hz), 7.22 (1H, t, J=8.1 Hz), 7.15 (1H, t, J=
.0 Hz) 7.06 (1H, s); d (aliphatic protons)=3.65 (4H, m,
CH -1 and CH -e), 3.00 (2H, t, J=6.8 Hz, CH -2), 2.14 (2H,
2
2
2
t, J=6.8 Hz, CH -a), 1.67 (2H, q, J=7.2 Hz, CH -b or CH -
2
2
2
d), 1.56 (2H, q, J=7.2 Hz, CH -b or CH -d), 1.37 (2H, m,
2
2
+
CH -c); ESI-MS (Da): m/z=297.15735 (4a+Na , calculated
2
+
+
for [C H N O +Na] : 297.15735), 571.32609 (2”4a+Na ,
calculated for [C H N O +Na] : 571.32548).
16
22
2
2
+
32
44
4
4
5
a: white solid; R =0.50 (eluent AcOEt-MeOH 10–0.5);
f
Figure 3. Compounds 2–6, 2a–6a, 2b–6b.
H NMR (ppm, CDCl , the spectrum is depicted in the Sup-
3
porting Information): d=4.07 (2H, dd, J=2.5 Hz, J=
was left overnight at 608C (see Table 1). After cooling to
08C, a small volume of CHCl was added, the enzyme and
5
.2 Hz, CH -2), 3.67 (2H, t, J=6.4 Hz, CH -e), 2.25 (1H, t,
2
2
4
J=2,6 Hz, CH-1), 2.24 (2H, t, J=7.3 Hz, CH -a), 1.70 (2H,
3
2
the molecular sieves were filtered, and a portion of the
q, J=7,6 Hz, CH -b or CH -d) and 1.61 (2H, q, J=7.1 Hz,
2
2
1
CH -b or CH -d), 1.43 (2H, m, J=7.1 Hz, CH -c).
crude reaction mixture was analyzed by H NMR to deter-
2
2
2
6
a: white solid; R =0.10 (eluent AcOEt); H NMR (ppm,
3
mine the percentage of monomer (e-CL) conversion
(Table 1). The remaining polymer was precipitated by
adding cold hexane, filtered and dried under vacuum (iso-
lated yields usually in the order of 80% w/w added mono-
mer). As reported in Table 1, different polymers carrying
different amines were synthesized, showing different degrees
of polymerization.
f
CDCl , the spectrum is depicted in the Supporting Informa-
tion): d=7.07 (2H, d, J=8.2 Hz) and 6.81 (2H, d, J=
.2 Hz), aromatic protons, 3.66 (2H, t, J=6.5 Hz, CH -e),
.51 (2H, quart, J=8.2 Hz, CH -NH), 2.77 (2H, t, J=
.7 Hz, CH -Ph), 2.16 (2H, t, J=7.2 Hz, CH -a), 1.59 (4H,
m, CH -b and CH -d), 1.40 (2H, m, CH -c).
8
3
6
2
2
2
2
2
2
2
2
b: yellow solid; H NMR (ppm, CDCl , the spectrum is
3
depicted in the Supporting Information):
d (polymer
Polymerization of e-CLin the Presence of Primary
Amines as an Initiator
chain)=4.08 (t, J=6.8 Hz, CH -d), 3.67 (t , J=6.8 Hz,
2
CH OH, CH -e), 2.33 (t, J=7.5 Hz, CH -a), 1.68 (m, CH -
2
2
2
2
In a typical polymerization reaction, the lactone, and the
amine in a 40:1 ratio (see Table 1) were added with a sy-
ringe into a two-necked, round-bottom flask. The flask was
heated at 708C for 2 h with continuous stirring and under
vacuum (generated by a water pump). The reaction mixture
b); 1.40 (m, CH -c); d (thiocolchicine moiety, selected
data)=7.40 (s, H-8), 7.35 (d, J=10.0 Hz, H-11), 7.05 (1H, d,
2
J=10.1 Hz, H-12), 6.55 (1H, s, H-4), 4.66 (1H, dt, J =
1
11.3 Hz, J =6.7 Hz, H-7), 3.96 (3H, s, OCH ), 3.92 (3H, s,
2
3
OCH ), 3.67 (3H, s, OCH ), 2.45 (3H, s, SCH ); ESI-MS
3
3
3
+
was flushed with N , then the enzyme (3% w/w e-CL) and
(selected data, Da): m/z=1650.87072 (2b+Na , with n=11;
+
ACHTREUNG
2
the molecular sieves (150 mg) were added, and the reaction
calculated for [C H NO S(C H O ) +Na] : 1650,87288),
20 22 4 6 10 2 11
Adv. Synth. Catal. 2007, 349, 1963 – 1968
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
1967

Mattia Marzorati et al.
FULL PAPERS
+
1
764.94223 (2b+Na , with n=12; calculated for Acknowledgements
+
[C H NO S
A
C
H
T
R
E
U
N
G
(C H O ) +Na] : 1764.94095), 1879.00924
20
22
4
6
10
2 12
+
(
2b+Na , with n=13; calculated for [C H NO S-
We thank Dr. Raniero Mendichi (ISMAC-CNR, Milano) for
his analytical support (SEC analysis).
2
0
22
4
+
A
C
H
T
R
E
U
N
G
(C H O ) +Na] : 1879.00903), SEC (THF): M =6,850,
6 10 2 13 n
M =12,250, d=1.79.
w
3
b (M/I 40/1): white solid; H NMR (ppm, CDCl , the
3
spectrum is depicted in the Supporting Information): d (po-
lymer chain)=4.07 (t, J=6.7 Hz, CH -d), 3.66 (t, J=6.7 Hz,
2
CH OH, CH -e), 2.32 (t, J=7.2 Hz, CH -a), 2.22 (t, J=
2
2
2
References
7
.1 Hz, CH -f), 1.66 (m, CH -b), 1.40 (m, CH -c); d (benzyl-
2 2 2
amine moiety)=7.38–7.26 (m, ArH), 4.43 (d, J=5.6 Hz,
[
1] S. Kobayashi, H. Uyama, S. Kimura, Chem. Rev. 2001,
101, 3793–3818.
PhCH ); ESI-MS (selected data, Da): m/z=1156.67576
2
+
+
(
1
3b+Na , with n=9; calculated for [C H N(C H O ) Na] :
A
H
R
U
7
9 6 10 2 9
+
[2] R. A. Gross, A. Kumar, B. Karla, Chem. Rev. 2001, 101,
2097–2124.
[3] D.-Y. Kim, X. Wu, J. S. Dordick, ACS Symp. Ser. 2002,
156.67544), 1384.81374 (3b+Na , with n=11; calculated
+
ACHTREUNG
for [C H N(C H O ) Na] : 1384.81160), 1612.95520 (3b+
9 6 10 2 11
+
AHCTREUGN
7
+
Na , with n=13; calculated for [C H N(C H O ) +Na] :
9 6 10 2 13
7
8
40, 34–49.
4] R. K. Srivastava, A. C. Albertsson, Macromolecules
006, 39, 46–54.
5] S. Riva, J. Mol. Catal. B: Enzymatic 2002, 19–20, 43–
4.
6] A. Cordova, T. Iversen, K. Hult, Macromolecules 1998,
1, 1040–1045.
1
612.94775), SEC (THF): M =8,050, M =14,500, d=1.80.
n w
[
[
[
[
4
b: white solid; H NMR (ppm, CDCl , the spectrum is de-
3
2
picted in the Supporting Information): d (polymer chain)=
4
.07 (t, J=6.8 Hz, CH -d), 3.66 (m, CH OH, CH -e), 2.31 (t,
2
2
2
5
J=7.6 Hz, CH -a), 2.16 (t, J=7.2 Hz, CH -f), 1.67 (m, CH -
2
2
2
b), 1.41 (m, CH -c); d (tryptamine moiety)=7.61 (d, J=
2
3
8
8
Hz), 7.40 (d, J=8.0 Hz), 7.23 (t, J=8.0 Hz), 7.15 (t, J=
7] K. S. Bisht, F. Deng, R. A. Gross, D. L. Kaplan, G.
.0 Hz), 7.06 (s), 3.65 (m, CH NH), 2.99 (t, J=6.8 Hz,
2
Swift, J. Am. Chem. Soc. 1998, 120, 1363–1367.
[8] J. I. Clark, T. N. Margulis, Life Sciences 1980, 26, 833–
836.
ArCH ); ESI-MS (selected data, Da): m/z=1209.70755
2
+
(
4b+Na , with n=9; calculated for [C H N(C H O ) +
A
T
E
N
1
0
12 6 10 2 9
+
+
Na] : 1209.70199), 1665.97807 (4b+Na , with n=13; calcu-
lated for [C H N(C H O ) +Na] : 1665.97430); SEC
+
[9] M. H. Zweig, C. F. Chignell, Biochemical Pharmacolo-
A
H
R
U
G
10
12 6 10 2 13
gy 1973, 22, 2141–2150.
10] B. Danieli, P. De Bellis, G. Carrea, S. Riva, Gazz.
(
THF): M =7,400, M =13,500, d=1.82.
n w
[
[
[
5
b: white solid; H NMR (ppm, CDCl , the spectrum is de-
3
Chim. It. 1991, 121, 123–126.
picted in the Supporting Information): d (polymer chain)=
11] B. Danieli, M. Luisetti, G. Sampognaro, G. Carrea, S.
Riva, J. Mol. Catal. B: Enzymatic 1997, 3, 193–201.
12] M. De Geus, L. Schormans, A. R. A. Palmans, C. E.
Koning, A. Heise, J. Polym. Sci., Part A: Polym. Chem.
2006, 44, 4290–4297.
4
.07 (t, J=6.7 Hz, CH -d), 3.65 (t, J=6.5 Hz, CH OH, CH -
2
2
2
e), 2.33 (t, J=7.3 Hz, CH -a), 2.21 (t, J=7.1 Hz, CH -f), 1.66
2
2
(
m, CH -b), 1.39 (m, CH -c); d (propargyl amine moiety)=
2
2
4
.08 (m, CH -2), 2.23 (m, CH -1): ESI-MS (selected data,
2 2
+
Da): m/z=762.44001 (5b+ Na , with n=6; calculated for
+
+
[13] H. Uyama, S. Suda, S. Kobayashi, Acta Polym. 1998,
49, 700–703.
[14] S. Tawaki, A. M. Klibanov, J. Am. Chem. Soc. 1992,
114, 1882–1884.
[C H N
A
C
H
T
R
E
U
N
G
(C H O ) Na] : 762.43990), 876.50966 (5b+ Na ,
3
5
6
10
2
6
+
with
8
n=7;
calculated
for
[C H N(C H O ) Na] :
A
T
E
N
3
5 6 10 2 7
+
76.50798), 990.57637 (5b+Na , with n=8; calculated for
+
ACHTREUNG
[C H N(C H O ) Na] : 990.57606); SEC (THF): M =8,150,
3 5 6 10 2 8 n
[
15] L. A. Henderson, Y. Y. Svirkin, R. A. Gross, D. L.
Kaplan, G. Swift, Macromolecules 1996, 29, 7759–7766.
16] L. Van der Mee, F. Helmich, R. de Bruijn, J. A. J. M.
Vekemans, A. R. A. Palmans, E. W. Meijer, Macromo-
lecules 2006, 39, 5021–5027.
M =14,600, d=1.79.
w
6
b: white solid; H NMR (ppm, CDCl , the spectrum is de-
3
[
picted in the Supporting Information): d (polymer chain)=
4
.08 (t, J=6.8 Hz, CH -d), 3.65 (t, J=6.5 Hz, CH OH, CH -
2
2
2
e), 2.32 (t, J=7.2 Hz, CH -a), 2.20 (t, J=7.1 Hz, CH -f), 1.66
2
2
[
17] a) R. Riva, S. Schmeits, C. Jerome, R. Jerome, P. Le-
comte, Macromolecules 2007, 40, 796–803; b) J. F.
Lutz, Angew. Chem. Int. Ed. 2007, 46, 1018–1025.
(
m, CH -b), 1.38 (m, CH -c); d (tyramine amine moiety)=
2
2
7.06 and 6.79 (d each, ArH), 3.50 (quart, J=6.9 Hz, CH2-
NH), 2.76 (t, J=7.2 Hz, CH -Ph); ESI-MS (selected data,
2
+
[18] T. Fukuoka, H. Uyama, S. Kobayashi, Macromolecules
Da): m/z=844.48251 (6b+Na , with n=6; calculated for
+
+
2004, 37, 8481–8484.
[19] M. Schappacher, A. Soum, S. M. Guillaume, Biomacro-
molecules 2006, 7, 1373–1379.
[
C H NO(C H O ) Na] : 844.48176), 958.55094 (6b+Na ,
6 10 2 6
+
ACHTREUNG
A
C
H
T
R
E
U
N
G
8
11
with n=7; calculated for + [C H NO(C H O ) Na] :
8
11
6 10 2 7
9
[
58.55094), 1072.61929 (5b+Na , with n=8; calculated for
+
ACHTREUNG
[20] T. J. Deming, J. Polym. Sci., Part A: Polym. Chem.
C H NO(C H O ) Na] : 1072.61792); SEC (THF): M =
8 11 6 10 2 8 n
1
993, 31, 275–278.
8
,100, M =14,500, d=1.79.
w
[
21] A. Kowalski, J. Libiszowski, T. Biela, M. Cypryc, A.
Duda, S. Penczek, Macromolecules 2005, 38, 8170–
Supporting Information Available
8
175.
1
H NMR spectra of compounds 1a, 3a, 3b, 4a, 4b, 5a, 5b, 6a
and 6b.
[22] P. Kerekes, P. N. Sharma, A. Brossi, C. F. Cignell, F. R.
Quinn, J. Med. Chem. 1985, 28, 1204–1208.
1968
asc.wiley-vch.de
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2007, 349, 1963 – 1968