Synthesis of carbosilane dendrons and dendrimers derived from 1,3,5-trihydroxybenzene

Article abstract of DOI:10.1016/j.tet.2010.09.063

Several carbosilane wedges of generations 1-3 have been synthesized, following the divergent method, containing at the focal point a C-Br bond and as peripheral functional groups SiMeCl₂, SiMe(C₃H ₅)₂, SiMe₂Cl, SiMe₂H, and ester units SiMe₂{(C₃H₆)N(C₂H ₄CO₂Me)₂}. The dendrons functionalized with SiMe(C₃H₅)₂ and SiMe₂{(C ₃H₆)N(C₂H₄CO₂Me) ₂} groups were used to synthesize spherical dendrimers derived from 1,3,5-(HO)₃C₆H₃, leaving the outer groups unchanged. The allyl dendrimers thus obtained were used as precursors to prepare new dendrimers functionalized with SiMeCl₂, SiMe₂Cl, SiMe₂H, amine units SiMe₂{(C₃H ₆)NH₂} and also ester units SiMe₂{(C ₃H₆)N(C₂H₄CO₂Me) ₂}.

Full text of DOI:10.1016/j.tet.2010.09.063

Tetrahedron 66 (2010) 9203e9213
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis of carbosilane dendrons and dendrimers derived from
1,3,5-trihydroxybenzene
,
,
,
,c,
*
Javier Sánchez-Nieves a c, Paula Ortega a c, M. Ángeles Muñoz-Fernández b c, Rafael Gómez a
,
,c,
F. Javier de la Mata a
*
a Dpto. de Química Inorgánica, Universidad de Alcalá, Campus Universitario, Alcalá de Henares, E-28871 Madrid, Spain
b Laboratorio de Inmunología Molecular, Hospital General Gregorio Marañón, Madrid, Spain
c CIBER-BBN, Zaragoza, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 21 July 2010
Received in revised form 9 September 2010
Accepted 17 September 2010
Available online 22 September 2010
Several carbosilane wedges of generations 1e3 have been synthesized, following the divergent method,
containing at the focal point a CeBr bond and as peripheral functional groups SiMeCl2, SiMe(C3H5)2,
SiMe2Cl, SiMe2H, and ester units SiMe2{(C3H6)N(C2H4CO2Me)2}. The dendrons functionalized with SiMe
(C3H5)2 and SiMe2{(C3H6)N(C2H4CO2Me)2} groups were used to synthesize spherical dendrimers derived
from 1,3,5-(HO)3C6H3, leaving the outer groups unchanged. The allyl dendrimers thus obtained were
used as precursors to prepare new dendrimers functionalized with SiMeCl2, SiMe2Cl, SiMe2H, amine
units SiMe2{(C3H6)NH2} and also ester units SiMe2{(C3H6)N(C2H4CO2Me)2}.
Keywords:
Dendron
Dendrimer
Silicon
Ó 2010 Elsevier Ltd. All rights reserved.
Allyl
1. Introduction
opposite procedure. This second method generates the so-called
dendritic wedges or dendrons, which are cone-shaped molecules with
Dendrimer molecules have been studied for several applications
as catalysis, material sciences and nano-biotechnology.1e14 Some of
the reasons that have attracted the interest toward these molecules
are their well defined and uniform branching structure, multivalency,
and varietyof typologies.15e17 For biomedicalapplications, apart from
low cytotoxicity, the surface of the dendrimers has to give adequate
solubility in aqueous media.18e21 Dendrimers functionalized at the
peripherywithamine groupscanfulfillthisgoal by theirownorbeing
transformed to cationic22e27 or anionic28e30 functionalities.
One type of dendrimer molecules is formed by a carbosilane
scaffold.31e38 The strength of these dendrimers is related to the high
energy of the CeSi bond and also its low polarity. This last character-
istic of the CeSi bond endows high hydrophobicity to carbosilane
dendrimers. However, this can be modified by functionalization of the
periphery with polar moieties, turning them hydrophilic and thus,
carbosilane dendrimers have also been used in biomedical
applications.39e44
two different functions, one at the periphery and other at the focal
point. This last procedure also gives dendrimers with lower dispersity,
due to the formation of less damaged branches during their synthesis.
Furthermore, dendrons can be employed to synthesize asymmetrical
dendrimers by coupling different units.48e50 Carbosilane dendrimers
have been mainly synthesized following the divergent synthesis, al-
though a few examples of carbosilane wedges are known.51e54
In this work, we present the synthesis of newcarbosilane dendrons
synthesized by divergent procedures with a CeBr bond at their focal
point. Someof thenew dendrons hereobtained havebeenalsoused as
building blocks for spherical dendrimers by coupling with 1,3,5-
(HO)3C6H3. We are interested to obtain water soluble dendrons and
dendrimers for various biomedical applications and, for that reason,
precursors for these molecules containing amine or ester groups as
terminated units have been synthesized. Furthermore, the presence of
the 1,3,5-(O)3C6H3 core would lead to carbosilane dendrimers less
congested than related dendrimers with a silicon atom core.41
Dendrimers are synthesized following two main synthetic meth-
ods.45e47 The divergent approach builds dendrimers from the core to
the periphery, whereas the convergent methodology consists in the
2. Results and discussion
2.1. Carbosilane wedges
The synthesis of the carbosilane wedges have been carried
out following previous described procedures,52 consistent in
* Corresponding authors. Tel.: þ34 91 885 4685; fax: þ34 91 885 4683; e-mail
addresses: rafael.gomez@uah.es (R. Gómez), javier.delamata@uah.es (F.J. de la Mata).
0040-4020/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.09.063

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J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
hydrosilylation with chlorosilanes of an alkenyl group and sub-
sequent alkenylation with a Grignard reagent. Thus, starting from 4-
Br-butene and employing HSiCl2Me, in the presence of Karstedt Pt
catalyst,55 and MgBr(C3H5), the dendritic wedges BrGn(SiCl2)m (n¼1,
m¼1 (1); n¼2, m¼2 (3); n¼3, m¼4 (5)) and BrGn(C3H5)m (n¼1, m¼2
(2); n¼2, m¼4 (4); n¼3, m¼8 (6)) (generations 1e3) were obtained
after repeating each pair of steps the number of required times
(Scheme 1, Fig. 1). We have considered increase of generation in
these dendrons, and also dendrimers, after hydrosilylation with
HSiCl2Me. With this procedure, the CeBr bond located at the focal
point remained unaltered in the alkenylation reaction of the SieCl
bond. The yield of these reactions was independent of the dendron
generation, being over 95% for the hydrosilylation and over 75% for
the alkenylation reaction.
at ca. d 0.80 belonging to the SiMeCl2 methyl group and also the
disappearance of the resonances belonging to the allyl moiety. In
the 13C NMR spectra of these compounds, the resonance of these
peripheral SiMeCl2 methyl groups was observed about d 5.0. On the
other hand, the 1H NMR spectra of the allyl dendrons BrGn(C3H5)m
(2, 4, 6) showed the characteristics signals of the allyl group,
a doublet about
d
1.50 (SiCH2eCH), and two multiplets about
d 4.60
(CH]CH2) and
d 5.10 (CH]CH2) and also the displacement of the
external SiMe(C3H5)2 methyl group to lower frequency (
d
¼ꢀ0.50).
A similar behavior was observed in the 13C NMR spectra of these
compounds with respect to the peripheral SiMe(C3H5)2 methyl
groups, observing a resonance about
d
ꢀ5.0. With respect to the
allyl moiety, the resonances corresponding to the Csp2 atoms were
observed at ca.
d
113.0 and
d
135.0. In all these compounds, the
ii
i
SiMeCl2
Si
Br
Br
Br
2
2
1
i
ii
Si
SiCl2
Si
Br
Si
2
Br
2
2
3
4
i
ii
Si
Si
Si
Si
Si
SiCl2
Br
Br
2
2
2
2
2
6
5
Scheme 1. Synthesis of dendrons 1e6. (i) HSiMeCl2, Karstedt’s catalyst; (ii) MgBr(C3H5).
Fig. 1. Drawing of G2 dendrons synthesized in this work.
These compounds were characterized by NMR spectroscopy (1H,
13C, 29Si) and elemental analysis. Formation of the BrGn(SiCl2)m (1,
3, 5) dendrons was confirmed in the 1H NMR spectra by one singlet
presence of the Br atom at the focal point was confirmed in the 1H
NMR spectra by a triplet at
ca. 2.40 and in the 13C NMR spectra by
one resonance at ca. 31.5. Also, for these two type of compounds,
d
d

J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
9205
1He29Si 2D HMBC spectroscopy was used to determine the pres-
ence of the different Si atoms. The resonance corresponding to the
CeBr bond at the focal point favored the quaternization of the N
atom instead of hydrosilylation of the amine, leading to a mixture
of compounds.
Si atom of the SiMeCl2 group was observed about
peripheral SiMe(allyl)2 groups between 2e3 and that of the in-
ternal SiMe(CH2)3 about 1.0.
d 31.0, that to the
d
However, with the aim to obtain a dendritic wedge with ter-
minal ester groups, we studied the reaction of SieH dendrons 8, 11,
and 14 with (C3H5)N(C2H4CO2Me)2.57 In this case, the hydro-
silylation in the presence of Pt catalyst proceeded smoothly giving
the desired compounds BrGn(C2H4CO2Me)m (n¼1, m¼4 (9); n¼2,
m¼8 (12); n¼3, m¼16 (15)) (Scheme 2, Fig. 1) in high yields (over
90%). It is important to note that the ester moiety remained un-
altered in this reaction, not observing hydrosilylation of the C]O
bond. The reaction was followed by NMR spectroscopy. The dis-
appearance of the doublet belonging to the starting SiMe2H methyl
groups and the multiplet of the SiH proton was indicative of the
outcome of the reaction. The main resonances of the 1H NMR
d
The next goal in this work was to transform the periphery of the
allyl-terminated BrGn(C3H5)m dendrons to terminal SieH units. This
was achieved by hydrosilylation the allyl substituents with HSi-
Me2Cl, also in the presence of Karstedt Pt catalyst, and then by Cl/H
substitution with LiAlH4. Dendritic wedges of generation 1e3
BrGn(SiCl)m (n¼1, m¼2 (7); n¼2, m¼4 (10); n¼3, m¼8 (13)) and
BrGn(SiH)m (n¼1, m¼2 (8); n¼2, m¼4 (11); n¼3, m¼8 (14))
(Scheme 2, Fig.1) were thus synthesized. It is important to note that
this last reaction did not affect the BreC bond at the focal point, as
was confirmed by NMR spectroscopy (see above). Again, the yield of
these reactions was independent of the dendron generation, being
over 95% for the hydrosilylation and over 70% for the substitution
reaction. It is important to note that heating the hydrosilylation
reaction speed up this process and also reduced the presence
of damaged branches by isomerization of the allyl moiety.56
spectra of compounds 9, 12 and 15 are the singlets at ca.
belonging to the OMe methyl groups, the two triplets about
d
3.60
2.40
d
and
triplet about
NMR experiment showed clearly the presence of the new Si(CH2)3N
d
2.70 for the CH2 groups of the chain NC2H4CO2Me and the
d
2.35 for the innermost CH2N groups. A 1He1H TOCSY
C3H5 (2)
SiRa
Ra
=
2
C3H6SiMe(C3H5)2 (4)
Br
6
C3H6SiMe(C3H6SiMe(C3H5)2)2 ( )
i
C3H6SiMe2Cl (7)
C3H6SiMe(C3H6SiMe2Cl)2 (10)
C3H6SiMe(C3H6SiMe(C3H6SiMe2Cl)2)2
SiRb
Rb
=
2
Br
13
(
)
ii
C3H6SiMe2H (8)
SiRc
2
Rc = C3H6SiMe(C3H6SiMe2H)2 (11)
Br
Br
14
C3H6SiMe(C3H6SiMe(C3H6SiMe2H)2)2
(
)
iii
C3H6SiMe2C3H6N(C2H4CO2Me)2 (9)
SiRd
Rd
=
2
C3H6SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2 (12)
C3H6SiMe(C3H6SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2)2
15
(
)
Scheme 2. Synthesis of dendrons functionalized with SiMe2Cl, SiMe2H, and SiMe2{(C3H6)N(C2H4CO2Me)2} groups. (i) HSiMe2Cl, Karstedt’s catalyst, 60 ꢁC; (ii) LiAlH4; (iii) (C3H5)N
(C2H4CO2Me)2, Karstedt’s catalyst, r. t.
All these new compounds were also characterized by NMR
spectroscopy (1H, 13C, 29Si) and elemental analysis. The 1H NMR
chain, with three cross peaks about
13C NMR spectroscopy, the main resonances were the corre-
sponding to the CO groups at ca. 173.0 and those for both CeN (
ca. 49.2 and 57.5) and CeCO ( ca. 32.5) carbon atoms. With respect
to the 29Si NMR spectroscopy, the disappearance of the low fre-
quency resonance of the SiMe2H silicon atom at
ca. ꢀ14.0 and the
observation of a new one at
d 2.35, d 1.35, and d 0.35. In the
spectra of dendrons 7, 10 and 13 showed one singlet at ca.
d
0.40
d
d
belonging to the SiMe2Cl methyl groups while the 1H NMR spectra
d
of the hydride dendrons 8,11, and 14 showed one multiplet at about
d
4.80 corresponding to the SiH proton and one doublet at about
0.04 for the SiMe2H methyl groups. A similar behavior was ob-
d
d
d
ca. ꢀ4.0 belonging to a new SiMe2
served in the 13C NMR spectra of these compounds with respect to
silicon atom also confirmed this reaction.
the Me2Si group, observing a resonance about
7, 10, and 13 and about
ꢀ4.0 for compounds 8, 11, and 14. The
presence of the SiMe2Cl group was also confirmed in the 1He29Si
HMBC spectra by one cross peak at about 31.0 for this Si atom,
whereas the SiMe2H groups gave a resonance clearly a lower fre-
quency (
As it has been comment before, dendrimers containing NH2
groups on the surface can be employed as precursors of cationic
NHþ3 and also anionic dendrimers. Thus, we tried to obtain den-
drons with peripheral NH2 groups by hydrosilylation of allylamine
(C3H5)NH2 with compounds BrGn(SiH)m (8, 11, 14), following pre-
viously reported procedure.41 Unfortunately, the presence of the
d 2.0 for compounds
d
2.2. Carbosilane dendrimers
d
The new dendrons synthesized were employed as synthons for
generation of new spherical dendrimers via convergent method-
ology. The core selected for this purpose was the polyphenolic
derivative 1,3,5-(HO)3C6H3, as the introduction of BreC bond con-
taining ligands to this type of units is well documented and proceed
through a simple methodology.47,58 The dendritic wedges with
SieCl terminal groups BrGn(SiCl2)m and BrGn(SiCl)m were dis-
charged for this reaction, due to the high reactivity of this bond. The
reaction with the SieH terminated dendrons BrGn(SiH)m failed
d
ca. ꢀ14.0) than any other silyl group in the molecule.

9206
J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
probably due to side-reactions of this bond with the base K2CO3 or
even with the CO2 released during this process. However, the re-
action was successful with the allyl BrGn(C3H5)m (3, 4, and 6) and
ester BrGn(C2H4CO2Me)m (9, 12) wedges, obtaining the respective
allyl GnO3(C3H5)m (n¼1, m¼6 (16); n¼2, m¼12 (17); n¼3, m¼24
(18)) and ester GnO3(C2H4CO2Me)m (n¼1, m¼12 (19); n¼2, m¼24
(20)) dendrimers (Scheme 3, Fig. 2). In contrast with the synthesis
of the dendritic wedges, now the reaction time is clearly dependent
on the generation wedge, lasting from few days for G1 to ca. 3
weeks for G3. In the particular case of the ester wedges, the cor-
responding G2 dendrimer G2O3(C2H4CO2Me)24 was obtained with
rather low yield and the reaction to synthesize the G3 dendrimer
was unsuccessful.
The main NMR data that confirm formation of these compounds
are the resonances of the newly formed CH2eO groups, which are
observed in the 1H NMR spectra at
d
ca. 3.80 and in the 13C NMR
spectra at
spectra one singlet about
resonances about 94.0 and
d
ca. 67.0. Furthermore, the C6H3 core gave in the 1H NMR
6.00 and in the 13C NMR spectra two
161.0 for the CH and i-C carbon atoms,
d
d
d
respectively, indicating the total substitution of the phenol groups.
The rest of resonances in the NMR spectroscopy are essentially the
same as those described for the corresponding dendrons.
C4H8SiMe(C3H5)2 (2)
C4H8SiMe(C3H6SiMe(C3H5)2)2 (4)
3 BrR
C4H8SiMe(C3H6SiMe(C3H6SiMe(C3H5)2)2)2 (6)
C4H8SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2 (9)
C4H8SiMe(C3H6SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2)2 (12)
R =
+
1,3,5-C6H3(OH)3
i
R
O
16
C4H8SiMe(C3H5)2
(
)
17
(
C4H8SiMe(C3H6SiMe(C3H5)2)2
C4H8SiMe(C3H6SiMe(C3H6SiMe(C3H5)2)2)2 (
C4H8SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2
C4H8SiMe(C3H6SiMe(C3H6SiMe2C3H6N(C2H4CO2Me)2)2)2
)
18
O
R
)
R =
19
(
)
O
R
20
(
)
Scheme 3. Synthesis of dendrimers with peripheral SiMe(C3H5)2 and SiMe2{(C3H6)N(C2H4CO2Me)2} groups. (i) K2CO3, crown ether 18C6, 90 ꢁC.
Fig. 2. Drawing of representative examples of G2 dendrimers synthesized in this work.

J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
9207
With this convergent procedure, we have been able to obtain
ester dendrimers, precursors of anionic derivatives, although with
low yields for higher generations, but not NH2 functionalized ones,
precursors of cationic dendrimers. For this purpose, we adopted the
synthetic strategy described previously to synthesize functional-
ized amine spherical dendrimers41 using the allyl dendrimers
GnO3(C3H5)m 16e18. Thus, hydrosilylation of 16e18 with HSiMe2Cl
afforded spherical dendrimers with SiMe2Cl terminated groups,
GnO3(SiCl)m (n¼1, m¼6 (22); n¼2, m¼12 (23); n¼3, m¼24 (24)),
and then Cl/H exchange with LiAlH4 led to dendrimers with SiMe2H
groups, GnO3(SiH)m (n¼1, m¼6 (25); n¼2, m¼12 (26); n¼3, m¼24
(27)) (Scheme 4). The NMR data of all these dendrimers are the
expected, as they have been described in the related dendrons
(see above and also Experimental part).
belonging to the starting SiMe2H methyl groups and the multiplet
belonging to the SiH proton was indicative of the outcome of the
reaction. Furthermore, a new resonance about d 2.65 corresponding
to the CH2N group was observed. The presence of the new Si(CH2)3N
chain was also confirmed by a 1H TOCSY-1D experiment, with three
resonances about
troscopy, the main resonance was that belonging tothe CH2N carbon
atom that gave a signal at
ca. 45.0. The 29Si NMR spectroscopy
showed the disappearance of the low frequency resonance of the
SiMe2H silicon atom at
ca. ꢀ14.0 and the observation of a new one
at
ca. ꢀ4.0 belonging to the new SiMe2 silicon atom.
These dendrimers 28e30 reacted with methyl acrylate
d 2.63, d 1.40 and d
0.48. In the 13C NMR spec-
d
d
d
C2H3CO2Me (room temperature, 16 h) to give the respective ester
dendrimers GnO3(C2H4CO2Me)m 19e21 (Scheme 4, Fig. 2). How-
16-18
GnO3(C3H5)m
(
)
i
Si
Si
SiMe2Cl
2
Ra
O
22
Si
SiMe2Cl
Si
Ra
=
2
2
O
23
Ra
Ra
O
Si
Si
SiMe2Cl
2
2
24
2
ii
Si
Si
SiMe2H
Rb
2
25
O
O
Si
SiMe2H
Rb
=
O
2
2
Rb
26
Rb
Si
Si
Si
SiMe2H
2
2
iii
27
2
Rc
Si
Si
Si
NH2
2
O
O
28
v
O
Si
Si
Si
Rc
=
NH2
2
Rc
Rc
2
29
NH2
Si
Si
Si
iv
2
2
2
30
19-21
GnO3(C2H4CO2Me)m
(
)
Scheme 4. Synthesis of dendrimers functionalized with SiMe2Cl, SiMe2H, SiMe2{(C3H6)NH2}, and SiMe2{(C3H6)N(C2H4CO2Me)2}. (i) HSiMe2Cl, Karstedt’s catalyst, 60 ꢁC; (ii) LiAlH4;
(iii) (C3H5)NH2, Karstedt’s catalyst, 120 ꢁC; (iv) C2H3CO2Me, rt; (v) (C3H5)N(C2H4CO2Me)2, Karstedt’s catalyst.
Dendrimers 25e27 reacted with (C3H5)NH2, in the presence of
Karstedt’s catalyst, to afford the amine dendrimers GnO3(NH2)m
(n¼1, m¼6 (28); n¼2, m¼12 (29); n¼3, m¼24 (30)) (Scheme 4,
Fig. 2), after several days over 120 ꢁC. In this case, the yield was much
lower for the G3 30 (30%) than for G1 and G2, 85% and 70%, re-
spectively. The difficulty to hydrosilylate amines would be increased
in the G3 compound 27 by higher congestion of functional groups.
Formation of compounds 28e30 was confirmed by NMR spectros-
copy. In the 1H NMR spectra the disappearance of the doublet
ever, they could also be obtained in one-step from the SieH func-
tionalized dendrimers GnO3(SiH)m 25e27 by reaction with (C3H5)N
(C2H4CO2Me)2 in THF (Scheme 4), in the presence of Karstedt’s
catalyst, after 16 h at room temperature for G1 and G2 and at 40 ꢁC
for G3. In this case, this hydrosilylation proceeded smoothly even in
the case of G3 dendrimer 27, obtaining the respective ester den-
drimers with high yields.
Finally, the allyl dendrimers GnO3(C3H5)m (n¼2, m¼12 (17); n¼3,
m¼24 (18)) could be also obtained following a divergent synthetic

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J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
strategy from the lower generation allyl dendrimer (16 for 17 and
17 for 18) by an analogous procedure described for the corre-
sponding allyl dendrons (Scheme 5), namely hydrosilylation of the
allyl dendrimer with HSiMeCl2 and then alkenylation with MgBr
(C3H5). With this method, the new dendrimers GnO3(SiCl2)m (n¼2,
m¼6 (31); n¼3, m¼12 (32)) functionalized with SiMeCl2 groups
were isolated. These dendrimers were characterized by NMR
spectroscopy, being their NMR spectra very similar to those de-
scribed in the related dendrons BrGn(SiCl2)m (1, 3, 5) (see above and
also Experimental part).
Fig. 3. GPC diagram of GnO3(C3H5)m (16 (a), 17 (b), 18 (c)).
m¼12 (26)) and the [MþNa]þ peak of dendrimers GnO3(C3H5)m (n¼2,
m¼12 (17); n¼3, m¼24 (18)). For the rest of compounds we could not
observed the corresponding molecular peak.
3. Conclusions
Dendritic wedges of generations 1e3 with a CeBr bond at the
focal point can be synthesized by iterative stepwise hydrosilylation
and alkenylation reactions with HSiCl2Me and MgBr(C3H5), re-
spectively. The allylic dendrons were also precursors of SiH func-
tionalized dendrons after hydrosilylation with HSiClMe2 and then
Cl/H exchange with LiAlH4. Nor the alkenylation neither the re-
action with LiAlH4 affected the CeBr bond. Ester dendritic wedges
can be also obtained from the SiH dendrons hydrosilylating with
the allyl ester compound (C3H5)N(C2H4CO2Me)2. However, this
procedure can not be employed with (C3H5)NH2 to obtain analo-
gous dendrons terminated in amine groups, because the presence
of the CeBr bond gave rise to quaternization of the amine.
The CeBr bond of the focal point has been useful to introduce the
allyl and ester wedges at the polyphenolic core 1,3,5-(HO)3C6H3, gen-
erating spherical dendrimers. However, the reaction time for the syn-
thesis of the G3 allyl dendrimer has resulted too long (over 20 days)
compared with G1 and G2 (2e6 days), whereas the reaction for the
synthesis of G3 ester dendrimers was unsuccessful. The allyl den-
drimers thus synthesized were used as precursors for amine den-
drimers, after hydrosilylation with HSiMe2Cl, exchange the Cl atom by
a H atom with LiAlH4 and then hydrosilylation with (C3H5)NH2. How-
ever, in this last case, this method gave low yield for the G3 dendrimer.
Ester dendrimers could be also obtained by adding the acrylate
C2H3CO2Me to the amine dendrimers or from the SiH dendrimers
by hydrosilylation with (C3H5)N(C2H4CO2Me)2, being the ester
moiety unaffected. The later procedure clearly shortens synthetic
times of ester derivatives with respect to the synthesis from
amines, requiring smoother conditions than hydrosilylation of
primary amines and also giving higher overall yields.
Scheme 5. Synthesis of dendrimers functionalized with SiMeCl2 and SiMe(C3H5)2. (i)
HSiMeCl2, Karstedt’s catalyst; (ii) MgBr(C3H5).
2.3. Characterization by gel permeation chromatography
(GPC) and mass spectrometry
The GPC analyses have been performed for the most relevant
dendrimers. The allyl dendrimers GnO3(C3H5)m showed narrow
polydispersity values (1.05 for 16, 1.10 for 17, 1.16 for 18; Fig. 3).
Similar values were obtained for the ester dendrimers GnO3(C2H4
-
CO2Me)m (19e21) synthesized by hydrosilylation of (C3H5)N
(C2H4CO2Me)2 with dendrimers GnO3(SiH)m 25e27 (1.06 for 19, 1.11
for 20, 1.18 for 21) and slightly higher for the amine dendrimers
GnO3(NH2)m (1.13 for 28, 1.21 for 29, 1.40 for 30). These values
confirm the high monodispersity degree of these systems.
Two different mass spectrometry techniques were used for char-
acterizationofdendronsanddendrimersESIandMALDI-TOF. Thefirst
one allowed us to determine the [MþH]þ peak of the dendrons
BrGn(C2H4CO2Me)m (9, 12, 15), whereas MALDI-TOF technique was
useful to find the [MþH]þ peak of dendrimers G1O3(C3H5)6 (16),
G1O3(C2H4CO2Me)12 (19), and GnO3(SiH)m (n¼1, m¼6 (25); n¼2,

J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
9209
4. Experimental section
0.99 (MeSi). Anal. Calcd C11H21BrSi (261.27 g/mol): C, 50.57; H, 8.10;
Exp.: C, 50.41; H, 7.93.
4.1. General considerations
4.2.4. BrG2(SiCl2)2 (3). Following the procedure described for
compound 1, compound 3 was obtained as a colorless liquid (7.60 g,
94%) from 2 (4.30 g, 0.016 mol) and HSiMeCl2 (7.58 g, 0.066 mol).
1H NMR (CDCl3): ꢀ0.03 (s, 3H, MeSi), 0.53 (m, 2H, SiCH2), 0.66
(m, 4H, SiCH2), 0.75 (s, 6H, MeSiCl2), 1.19 (m, 4H, CH2SiCl2), 1.50 (m,
All reactions were carried out under inert atmosphere and sol-
vents were purified from appropriate drying agents. NMR spectra
were recorded on a Varian Unity VXR-300 (300.13 (1H) and 75 (13C)
MHz) or on a Bruker AV400 (400.13 (1H) and 79.49 (29Si) MHz).
Chemical shifts (
d
) are given in parts per million. 1H and 13C reso-
6H, CH2), 1.85 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2); 13
C
nances were measured relative to solvent peaks considering
TMS¼0 ppm, meanwhile 29Si resonance were measured relative to
external TMS. When necessary, assignment of resonances was done
from HSQC, HMBC, COSY, TOCSY, and NOESY NMR experiments.
Elemental analyses were performed on a PerkineElmer 240C. Mass
Spectra were obtained from an Agilent 6210 (ESI) and a Bruker
Ultraflex III (MALDI-TOF). GPC analyses were carried out in a Varian
HPLC with Plgel Mixed-D (300ꢂ7.5 mm) columns from Polymer
Laboratories and a GPC Pl-ELS 1000 detector from Polymer Labo-
ratories. Compounds 4-Br-butene, Karstedt’s Pt catalyst, MgBr
(C3H5), LiAlH4, (C3H5)NH2 and C2H3CO2Me (Aldrich), HSiCl2Me, and
HSiClMe2 (ABCR) were obtained from commercial sources.
NMR{1H} (CDCl3): ꢀ5.1 (MeSi), 5.1 (MeSiCl2), 12.5 (SiCH2), 17.3
(CH2),17.9 (CH2), 22.3 (BrCH2CH2CH2), 25.9 (CH2SiCl2), 33.7 (BrCH2),
36.4 (BrCH2CH2); 29Si NMR (CDCl3): 2.3 (MeSi), 32.1 (MeSiCl2).
4.2.5. BrG2(C3H5)4 (4). Following the procedure described for
compound 2, compound 4 was obtained as a colorless liquid (5.10 g,
78%) from 3 (6.25 g, 0.013 mol) and BrMg(C3H5) (0.055 mol).
1H NMR (CDCl3):
d
ꢀ0.08 (s, 3H, MeSi), ꢀ0.04 (s, 6H, MeSi), 0.56
(m, 10H, SiCH2), 1.25 (m, 6H, CH2), 1.52 (d, J¼8.4 Hz, 8H, CH2CH]
CH2), 1.84 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2), 4.84 (m,
8H, CH]CH2), 5.74 (m, 4H, CH]CH2); 13C NMR{1H} (CDCl3):
d
ꢀ5.7
(MeSi), ꢀ5.1 (MeSi), 12.9 (SiCH2), 17.9, 18.2y 18.6 (CH2), 21.4
(CH2CH]CH2), 22.5 (BrCH2CH2CH2), 33.6 (BrCH2), 36.3 (BrCH2CH2),
4.2. Synthesis of compounds
113.0 (CH]CH2), 134.8 (CH]CH2); 29Si NMR (CDCl3):
d 0.1 (MeSi),
1.8 (MeSi). Anal. Calcd C25H49BrSi3 (513.82 g/mol): C, 58.44; H, 9.61;
4.2.1. (C3H5)N(C2H4CO2Me). (C3H5)NH2 (0.76 mL, 0.017 mol) and
C2H3CO2Me (3.30 mL, 0.040 mol) were stirred in MeOH (5 mL) at
60 ꢁC for 20 h. Afterward, volatiles were removed under vacuum
and (C3H5)N(C2H4CO2Me) (2.99 g, 98%,) was obtained as a colorless
liquid. Anal. Calcd for C11H19NO4 (229.27): C, 57.62; H, 8.35; N, 6.11;
Obt.: C, 57.69; H, 8.25; N, 6.05.
Exp.: C, 58.11; H, 9.54.
4.2.6. BrG3(SiCl2)4 (5). Following the procedure described for
compound 1, compound 5 was obtained as a colorless liquid (4.45 g,
94%) from 4 (2.50 g, 4.86 mmol) and HSiMeCl2 (3.80 g, 0.033 mol).
1H NMR (CDCl3):
d
ꢀ0.07 (s, 3H, MeSi), ꢀ0.04 (s, 6H, MeSi), 0.58
1H NMR (CDCl3): 2.46 (t, 4H, J¼7.2 Hz, NCH2CH2), 2.79 (t, 4H,
J¼7.2 Hz, CH2CO2Me), 3.10 (d, 2H, J¼6.6 Hz, CHCH2N), 3.67 (s, 6H,
CO2Me), 5.15 (m, 2H, CH2]CH), 5.80 (m, 2H, CH2]CH); 13C NMR
{1H} (CDCl3): 32.3 (CH2CO), 48.7 (CH2N), 51.3 (OMe), 56.7
(CHCH2N), 117.2 (CH2]CH), 135.2 (CH2]H), 172.7 (CO).
(m,18H, SiCH2), 0.75 (s,12H, MeSiCl2), 0.87 (m, 8H, CH2),1.16 (m, 8H,
CH2SiCl2), 1.52 (m, 6H, CH2), 1.85 (m, 2H, BrCH2CH2), 3.40 (t,
J¼6.6 Hz, 2H, BrCH2); 13C NMR{1H} (CDCl3):
d
ꢀ5.2 (MeSi), 5.5
(MeSiCl2), 12.9 (SiCH2), 17.3y 17.5 (CH2), 18.4, 18.6y 18.7 (CH2), 22.6
(BrCH2CH2CH2), 25.9 (CH2SiCl2), 33.6 (BrCH2), 36.3 (BrCH2CH2); 29Si
NMR (CDCl3):
d 1.4 (MeSi), 1.8 (MeSi), 32.1 (MeSiCl2).
4.2.2. BrG1(SiCl2) (1). HSiMeCl2 (7.67 g, 0.067 mol) was added to
a cooled solution of 4-Br-1-butene (4.50 g, 0.033 mol) in hexane
(3 mL) in the presence of Karstedt’s catalyst (3% mol) and stirred
overnight at 40 ꢁC. Afterward, volatiles were removed under vac-
uum, hexane was added (10 mL) and the solution was filtered
through active carbon. Removal of volatiles under vacuum (caution:
compound 1 is slightly volatile) gave 1 as a colorless liquid (7.76 g,
94%) (compound 1 is moisture sensitive and has to be stored under
inert atmosphere).
4.2.7. BrG3(C3H5)8 (6). Following the procedure described for
compound 2, compound 6 was obtained as a colorless liquid (2.62 g,
76%) from 5 (3.30 g, 3.39 mmol) and BrMg(C3H5) (3.45 mmol).
1H NMR (CDCl3):
d
ꢀ0.10 (s, 3H, MeSi), ꢀ0.08 (s, 6H, MeSi), ꢀ0.04
(s, 12H, MeSi), 055 (m, 26H, SiCH2), 1.31 (m, 16H, CH2), 1.52 (d,
J¼8.4 Hz, 16H, CH2CH]CH2), 1.84 (m, 2H, BrCH2CH2), 3.40 (t,
J¼6.6 Hz, 2H, BrCH2), 4.84 (m, 16H, CH]CH2), 5.73 (m, 8H, CH]
CH2); 13C NMR{1H} (CDCl3):
d
ꢀ5.7 (MeSi), ꢀ5.1 (MeSi), ꢀ4.9 (MeSi),
1H NMR (CDCl3): 0.77 (s, 3H, MeSiCl2), 1.11 (m, 2H, CH2Si), 1.65
(m, 2H, CH2CH2Si), 1.93 (m, 2H, BrCH2CH2), 3.41 (t, J¼6.6 Hz, 2H,
BrCH2); 13C NMR{1H} (CDCl3): 5.1 (MeSiCl2), 20.6 (CH2CH2Si), 21.1
(CH2CH2Si), 32.8 (BrCH2CH2), 34.9 (BrCH2CH2); 29Si NMR (CDCl3):
32.3 (MeSiCl2). Anal. Calcd for C5H11BrCl2Si (250.04): C, 24.02; H,
4.43; Obt.: C, 24.23; H, 4.61.
13.0 (SiCH2), 17.9, 18.3, 18.5, 18.8y 18.9 (CH2), 21.5 (CH2CH]CH2),
22.6 (BrCH2CH2CH2), 33.6 (BrCH2), 36.4 (BrCH2CH2), 113.1 (CH]
CH2), 134.9 (CH]CH2); 29Si NMR (CDCl3):
d 0.1 (MeSi), 0.9 (MeSi),
1.8(MeSi). Anal. Calcd C53H105BrSi7 (1018.90 g/mol): C, 62.48; H,
10.39; Exp.: C, 62.22; H, 10.31.
4.2.8. BrG1(SiCl)2 (7). Following the procedure described for com-
pound 1 but heating at 60 ꢁC, compound 7 was obtained as a col-
orless liquid (4.96 g, 96%) from the reaction of 2 (3.00 g, 0.011 mol)
and HSiMe2Cl (4.35 g, 0.046 mol).
4.2.3. BrG1(C3H5)2 (2). BrMg(C3H5) (0.061 mol) was slowlyadded to
a cooled Et2O solution (30 mL) of 1 (7.00 g, 0.028 mol) and stirred
overnight at room temperature. Afterward, awatersolution ofNH4Cl
was added (12%, 50 mL), the organic phase was separated and the
aqueous phase was extracted twice with Et2O. The organic phase
was washed with brine, dried over MgSO4, and SiO2. The solution
was filtered through active carbon and the volatiles were removed
under vacuum, yielding 2 as a colorless liquid (5.85 g, 80%).
1H NMR (CDCl3): ꢀ0.05 (s, 3H, MeSi), 0.38 (s, 12H, Me2SiCl), 0.52
(m, 2H, SiCH2), 0.58 (m, 4H, SiCH2), 0.88 (m, 4H, CH2SiCl), 1.42 (m,
6H, CH2), 1.85 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2); 13
C
NMR{1H} (CDCl3): ꢀ5.2 (MeSi), 1.9 (Me2Si), 12.8 (SiCH2), 17.7 (CH2),
17.9 (CH2), 22.4 (BrCH2CH2CH2), 23.5 (CH2SiCl), 33.6 (BrCH2), 36.3
(BrCH2CH2); 29Si NMR (CDCl3): 2.1 (MeSi), 31.1 (Me2SiCl).
1H NMR (CDCl3): ꢀ0.02 (s, 3H, MeSi(CH2CHCH2)2), 0.53 (m, 2H,
CH2Si), 1.44 (m, 2H, CH2CH2Si), 1.54 (d, J¼8.5 Hz, 4H, SiCH2CH), 1.85
(m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2), 4.84 (m, 4H, CH]
CH2), 5.74 (m, 2H, CH]CH2); 13C NMR{1H} (CDCl3): ꢀ5.9 (MeSi),
12.0 (SiCH2), 21.2 (CH2CH]CH2), 22.1 (CH2), 33.5 (BrCH2), 36.2
(BrCH2CH2), 113.3 (CH]CH2), 134.5 (CH]CH2); 29Si NMR (CDCl3):
4.2.9. BrG1(SiH)2 (8). An Et2O solution (40 mL) of 7 (2.00 g,
4.44 mmol) was slowly added to an Et2O solution (20 mL) of LiAlH4
(7.76 mmol) at 0 ꢁC and stirred overnight at room temperature.
Afterward, the mixture was added over a saturated water solution

9210
J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
of Na2SO4 (50 mL) at 0 ꢁC, the organic phase was separated and the
aqueous phase was extracted twice with Et2O. The organic phase
was dried over MgSO4, and SiO2, the solution was filtered and the
volatiles were removed under vacuum, yielding 8 as colorless oil
(1.44 g, 85%).
J¼6.6 Hz, 2H, BrCH2), 3.61 (s, 24H, OMe); 13C NMR{1H} (CDCl3):
d
ꢀ5.1 (MeSi), ꢀ4.9 (MeSi), ꢀ3.3 (Me2Si), 12.9 (SiCH2), 13.0 (SiCH2),
18.4, 18.5, 18.8, 18.9, 20.1 (CH2), 21.6 (CH2CH2N), 22.5
(BrCH2CH2CH2), 32.6 (CH2CO), 33.5 (BrCH2), 36.4 (BrCH2CH2), 49.3
(CH2N), 51.5 (OMe), 57.6 (CH2N), 173.0 (CO); 29Si NMR (CDCl3):
1H NMR (CDCl3):
d
ꢀ0.08 (s, 3H, MeSi), 0.04 (d, J¼4.2 Hz, 12H,
d
0.87 (MeSi), 1.7 (MeSi), 1.9 (Me2Si). MS [MþH]þ: 1669.92. Anal.
Me2SiH), 0.52 (m, 2H, SiCH2), 0.58 (m, 8H, SiCH2), 1.38 (m, 6H, CH2),
1.85 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2), 3.82 (m, 2H,
Calcd C77H157BrN4O16Si7 (1671.59 g/mol): C, 55.33; H, 9.47; N, 3.35;
Obt.: C, 55.98; H, 9.60; N, 3.28.
SiH); 13C NMR{1H} (CDCl3):
d
ꢀ5.1 (MeSi), ꢀ4.3 (Me2SiH), 12.9
(SiCH2), 17.9 (CH2), 18.8y 19.0 (CH2), 22.5 (BrCH2CH2CH2), 33.7
4.2.14. BrG3(SiCl)8 (13). Following the procedure described for
compound 7, compound 13 was obtained as a colorless oil (4.29 g,
94%) from the reaction of 6 (2.62 g, 2.57 mmol) and HSiMe2Cl
(3.31 g, 0.035 mol).
(BrCH2), 36.4 (BrCH2CH2); 29Si NMR (CDCl3):
d
ꢀ14.6 (Me2SiH), 2.1
(MeSi). Anal. Calcd C15H37BrSi3 (381.61 g/mol): C, 47.21; H, 9.77;
Obt.: C, 47.59; H, 9.53.
1H NMR (CDCl3): ꢀ0.07 (s.a., 21H, MeSi), 0.38 (s, 48H, Me2SiCl),
0.50 (m, 26H, SiCH2), 0.85 (m, 16H, CH2SiCl), 1.24 (m, 12H, CH2), 1.40
(m, 18H, CH2), 1.82 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2);
13C NMR{1H} (CDCl3): ꢀ5.0y ꢀ4.9 (MeSi), 1.8 (Me2SiCl), 13.0 (SiCH2),
17.7, 18.1, 18.5, 18.8 and 18.9 (SiCH2), 22.6 (BrCH2CH2CH2), 23.5
(CH2SiCl), 33.6 (BrCH2), 36.3 (BrCH2CH2); 29Si NMR (CDCl3): 0.9 and
1.2 (MeSi), 31.2(Me2SiCl).
4.2.10. BrG1(C2H4CO2Me)4
(9). C3H5N(C2H4CO2Me)2 (1.23 g,
5.26 mmol) was added to a hexane solution (5 mL) of 8 (1.00 g,
2.62 mmol) in the presence of Karstedt’s catalyst (3% mol) and stirred
overnight at room temperature. Afterward, hexane (10 mL) was
added, the solution was filtered through active carbon and the vola-
tiles were removed under vacuum. Compound 9 was purified by Gel
PermeationChromatography, obtaining9ascolorlessoil(2.04g,92%).
1H NMR (CDCl3):
d
ꢀ0.10 (s, 3H, MeSi), ꢀ0.08 (s,12H, Me2Si), 0.33
4.2.15. BrG3(SiH)8 (14). Following the procedure described for
compound 8, compound 14 was obtained as a colorless oil (1.32 g,
78%) from the reaction of 13 (2.00 g, 1.13 mmol) and LiAlH4
(6.75 mmol).
(m, 4H, SiCH2), 0.52 (m, 10H, SiCH2), 1.27 (m, 4H, CH2), 1.35 (m, 6H,
CH2), 1.83 (m, 2H, BrCH2CH2), 2.33 (m, 4H, CH2N), 2.41 (t, J¼7.3 Hz,
8H, CH2N), 2.74 (t, J¼7.3 Hz, 8H, CH2CO), 3.39 (t, J¼6.6 Hz, 2H,
BrCH2), 3.61 (s, 12H, OMe); 13C NMR{1H} (CDCl3):
d
ꢀ5.1 (MeSi),
1H NMR (CDCl3):
d
ꢀ0.10 (s, 21H, MeSi), 0.04 (d, J¼4.2 Hz, 48H,
ꢀ3.3 (Me2Si), 12.8 (SiCH2), 12.9 (SiCH2), 18.4 (CH2), 18.6y 20.1 (CH2),
21.5 (CH2CH2N), 22.5 (BrCH2CH2CH2), 32.5 (CH2CO), 33.7 (BrCH2),
36.4 (BrCH2CH2), 49.2 (CH2N), 51.6 (OMe), 57.5 (CH2N), 173.1 (CO);
Me2SiH), 0.58 (m, 58H, SiCH2), 1.31 (m, 30H, CH2), 1.82 (m, 2H,
BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2), 3.83 (m, 8H, SiH); 13C NMR
{1H} (CDCl3):
d
ꢀ5.0 to ꢀ4.8 (MeSi), ꢀ4.3 (Me2SiH), 13.0 (SiCH2),
29Si NMR (CDCl3):
Anal. Calcd C37H75BrN2O8Si3 (840.16 g/mol): C, 52.89; H, 9.00; Obt.:
C, 52.29; H, 8.63.
d
1.0 (Me2Si), 2.1 (MeSi). MS [MþH]þ: 839.41.
18.2e19.0 (CH2), 22.6 (BrCH2CH2CH2), 33.5 (BrCH2), 36.5
(BrCH2CH2); 29Si NMR (CDCl3):
d
ꢀ14.6 (Me2SiH), 1.4 (MeSi). Anal.
Calcd C69H169BrSi15 (1500.27 g/mol): C, 55.24; H, 11.35; Obt.: C,
55.88; H, 11.73.
4.2.11. BrG2(SiCl)4 (10). Following the procedure described for
compound 7, compound 10 was obtained as a colorless oil (4.08 g,
94%) from the reaction of 4 (2.50 g, 4.86 mmol) and HSiMe2Cl
(3.31 g, 0.035 mol).
4.2.16. BrG3(C2H4CO2Me)16 (15). Following the procedure de-
scribed for compound 9, compound 15 was obtained as a colorless
oil (0.98 g, 88%) from the reaction of 14 (0.50 g, 0.33 mol) and C3H5N
(C2H4CO2Me)2 (0.63 g, 0.34 mol).
1H NMR (CDCl3): ꢀ0.08 (s, 3H, MeSi), ꢀ0.07 (s, 6H, MeSi), 0.38 (s,
24H, Me2SiCl), 0.54 (m, 18H, SiCH2), 0.86 (m, 8H, CH2SiCl), 1.28 (m,
4H, CH2), 1.42 (m, 10H, CH2), 1.85 (m, 2H, BrCH2CH2), 3.40 (t,
J¼6.6 Hz, 2H, BrCH2); 13C NMR{1H} (CDCl3): ꢀ5.1 (2 MeSi), 1.8
(Me2SiCl), 12.9 (SiCH2), 17.7, 18.1, 18.4, 18.7 (CH2), 22.5
(BrCH2CH2CH2), 23.5 (CH2SiCl), 33.7 (BrCH2), 36.3 (BrCH2CH2); 29Si
NMR (CDCl3): 1.0 (MeSi), 2.0 (MeSi), 31.2 (Me2SiCl).
1H NMR (CDCl3):
d
ꢀ0.10 (s, 18H, MeSi), ꢀ0.06 (s, 51H, MeSi and
Me2Si), 0.35 (m, 16H, SiCH2), 0.53 (m, 58H, SiCH2), 1.27 (m, 30H,
CH2), 1.37 (m, 16H, CH2), 1.83 (m, 2H, BrCH2CH2), 2.37 (m, 16H,
CH2N), 2.42 (t, J¼7.3 Hz, 32H, CH2N), 2.75 (t, J¼7.3 Hz, 32H, CH2CO),
3.40 (t, J¼6.6 Hz, 2H, BrCH2), 3.64 (s, 48H, OMe); 13C NMR{1H}
(CDCl3):
d
ꢀ5.0 (MeSi), ꢀ4.9 (MeSi), ꢀ3.3 (Me2Si), 12.7 (SiCH2), 12.8
(SiCH2), 18.4, 18.8, 19.0, 20.1 (CH2), 21.5 (CH2CH2N), 22.5
(BrCH2CH2CH2), 32.5 (CH2CO), 33.5 (BrCH2), 36.4 (BrCH2CH2), 49.2
4.2.12. BrG2(SiH)4 (11). Following the procedure described for
compound 8, compound 11 was obtained as a colorless oil (2.18 g,
82%) from the reaction of 10 (3.15 g, 3.53 mmol) and LiAlH4
(10.60 mmol).
(CH2N), 51.5 (OMe), 57.5 (CH2N), 1731 (CO); 29Si NMR (CDCl3):
d 0.87
(MeSi), 1.7 (MeSi), 1.9 (Me2Si). MS [MþH]þ: 3330.87. Anal. Calcd
C157H321BrN8O32Si15 (3334.45 g/mol): C, 56.55; H, 9.70; N, 3.36;
Obt.: C, 56.79; H, 9.41; N, 3.28.
1H NMR (CDCl3):
d
ꢀ0.10 (s, 6H, MeSi), ꢀ0.08 (s, 3H, MeSi), 0.04
(d, J¼4.2 Hz, 12H, Me2SiH), 0.54 (m, 26H, SiCH2), 1.35 (m, 14H, CH2),
1.85 (m, 2H, BrCH2CH2), 3.40 (t, J¼6.6 Hz, 2H, BrCH2), 3.82 (m, 4H,
4.2.17. G1O3(C3H5)6 (16). 1,3,5-(HO)3C6H3 (0.48 g, 3.82 mmol), 2
(3.00 g, 11.48 mmol), K2CO3(3.20 g, 23.00 mmol) and crown ether
18-C-6 (0.30 g, 1.14 mmol) were stirred in acetone (70 mL) at 90 ꢁC
into a sealed ampoule for 3 days under vacuum. Afterward, volatiles
were removed under vacuum and a water solution of NH4Cl (12%,
50 mL) and Et2O were added. The organic phase was separated and
the aqueous phase was extracted twice with Et2O. The organic
phase was dried over MgSO4, and for extra 10 min also with SiO2.
The solution was filtered and the volatiles were removed under
vacuum, yielding 16 as colorless oil (2.02 g, 80%).
SiH); 13C NMR{1H} (CDCl3):
d
ꢀ5.0 (MeSi), ꢀ4.38 (Me2SiH), 13.0
(SiCH2), 18.2, 18.5, 18.7, 18.8, 19.0 (CH2), 22.5 (BrCH2CH2CH2), 33.6
(BrCH2), 36.4 (BrCH2CH2); 29Si NMR (CDCl3):
d
ꢀ14.1 (Me2SiH), 1.0
(MeSi), 1.8 (MeSi). Anal. Calcd C33H81BrSi7 (754.50 g/mol): C, 52.53;
H, 10.82; Obt.: C, 52.80; H, 10.45.
4.2.13. BrG2(C2H4CO2Me)8 (12). Following the procedure described
for compound 9, compound 12 was obtained as a colorless oil
(0.60 g, 91%) from the reaction of 11 (0.30 g, 0.40 mmol) and C3H5N
(C2H4CO2Me)2 (0.40 g, 1.75 mmol).
1H NMR (CDCl3):
(m, 6H, OCH2CH2CH2), 1.54 (d, J¼8.5 Hz, 12H, CH2CH]CH2), 1.76 (m,
6H, OCH2CH2), 3.89 (t, J¼6.4 Hz, 6H, OCH2), 4.84 (m, 12H, CH]CH2),
5.78 (m, 6H, CH]CH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
d
ꢀ0.02 (s, 9H, MeSi), 0.58 (m, 6H, CH2Si), 1.44
1H NMR (CDCl3):
d
ꢀ0.10 (s, 6H, MeSi), ꢀ0.08 (s, 3H, MeSi), ꢀ0.07
(s, 24H, Me2Si), 0.37 (m, 8H, SiCH2), 0.52 (m, 26H, SiCH2), 1.33 (m,
22H, CH2), 1.83 (m, 2H, BrCH2CH2), 2.33 (m, 8H, CH2N), 2.41 (t,
J¼7.3 Hz, 16H, CH2N), 2.74 (t, J¼7.3 Hz, 16H, CH2CO), 3.39 (t,
d
ꢀ5.9 (MeSi), 12.7 (SiCH2), 20.1 (OCH2CH2CH2), 21.3 (CH2CH]CH2),

J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
9211
32.9 (OCH2CH2), 67.4 (OCH2), 93.7 (C6H3 (CH)), 113.1 (CH]CH2),
C117H228N6O27Si9 (2403.86 g/mol): C 58.46, H, 9.56, N, 3.50; Obt.: C,
58.09, H, 9.13, N, 3.02.
134.7 (CH]CH2), 160.9 (i-C6H3); 29Si NMR (CDCl3):
d
0.8 (MeSi). MS
[MþH]þ: 667.44. Anal. Calcd C39H66O3Si3 (667.20 g/mol): C, 70.21;
H, 9.97; Obt.: C, 69.83; H, 9.22.
4.2.21. G2O3(C2H4CO2Me)24 (20). Method (B): Compound 20 was
obtained as a pale yellow oil (2.10 g, 88%) from the reaction of 26
(1.05 g, 0.48 mmol) and C3H5N(C2H4CO2Me)2 (1.34 g, 5.94 mmol) as
described for compound 19. Method (C): Starting from C2H3CO2Me
(0.25 g, 2.92 mmol) and 29 (0.30 g, 0.11 mmol) compound 20 was
isolated as a yellowish oil (0.46 g, 89%) following the procedure
described for 19 (method C).
4.2.18. G2O3(C3H5)12 (17). Following the procedure described for
compound 16, compound 17 was obtained as a colorless oil (2.07 g,
76%) from the reaction of 1,3,5-(HO)3C6H3 (0.24 g, 1.94 mmol), 4
(3.00 g, 5.84 mmol), K2CO3 (1.62 g, 11.68 mmol), and 18-C-6 (0.15 g,
0.59 mmol) during 7 days.
1H NMR (CDCl3):
d
ꢀ0.08 (s, 9H, MeSi), ꢀ0.04 (s, 18H, MeSi),
1H NMR (CDCl3):
d
ꢀ0.10 (s, 27H, MeSi), ꢀ0.07 (s, 72H, Me2Si),
0.57 (m, 30H, SiCH2), 1.30 (m, 12H, CH2), 1.41 (m, 6H,
OCH2CH2CH2), 1.52 (d, J¼7.9 Hz, 24H, CH2CH]CH2), 1.75 (m, 6H,
OCH2CH2), 3.88 (t, J¼6.3 Hz, 6H, OCH2), 4.84 (m, 24H, CH]CH2),
5.74 (m, 12H, CH]CH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
0.39 (m, 24H, SiCH2), 0.53 (m, 78H, SiCH2), 1.30 (m, 66H, CH2), 1.75
(m, 6H, OCH2CH2), 2.39 (m, 24H, CH2N), 2.41 (t, J¼7.3 Hz, 48H,
CH2N), 2.74 (t, J¼7.3 Hz, 48H, CH2CO), 3.64 (s, 72H, OMe), 3.87 (t,
J¼6.6 Hz, 6H, OCH2), 6.03 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
ꢀ5.1
d
d
ꢀ5.7 (MeSi), ꢀ5.1 (MeSi), 13.8 (SiCH2), 17.9, 18.2y 18.6 (CH2), 20.6
(MeSi), ꢀ3.3 (Me2Si), 12.8 (SiCH2), 13.9 (SiCH2), 18.4, 18.8, 19.0y 20.1,
20.5, 21.5 (CH2), 32.5 (NCH2), 33.7 (OCH2CH2), 49.2 (CH2CO), 51.2
(OMe), 57.5 (CH2N), 67.7 (OCH2), 93.6 (C6H3 (CH)), 160.9 (i-C6H3),
(OCH2CH2CH2), 21.5 (CH2CH]CH2), 33.3 (OCH2CH2), 67.6 (OCH2),
93.7 (C6H3 (CH)), 113.1 (CH]CH2), 134.9 (CH]CH2), 160.9 (i-C6H3);
29Si NMR (CDCl3):
d
0.1 (MeSi), 1.5 (MeSi). [MþNa]þ: 1446.9. Anal.
173.1 (CO); 29Si NMR (CDCl3):
d 0.9 (MeSi), 1.7 (MeSi), 1.9 (Me2Si).
Calcd C81H150O3Si9 (1424.83 g/mol): C 68.28; H 10.61; Obt.: C,
68.01; H, 10.31.
Anal. Calcd C237H474N12O51Si21 (4898.14 g/mol): C, 58.11; H, 9.75; N,
3.43; Obt.: C, 57.89; H, 10.01; N, 3.63.
4.2.19. G3O3(C3H5)24 (18). Following the procedure described for
compound 16, compound 17 was obtained as a colorless oil (1.00 g,
68%) from the reaction of 1,3,5-(HO)3C6H3 (0.061 g, 0.49 mmol), 6
(1.50 g, 1.47 mmol), K2CO3 (0.41 g, 2.94 mmol), and 18-C-6 (0.039 g,
0.14 mmol) during 20 days.
4.2.22. G3O3(C2H4CO2Me)48 (21). Method (B): Following the pro-
cedure described for compound 19 (method B), compound 21 was
obtained as a pale yellow oil (0.31 g, 88%) from the reaction of 26
(0.15 g, 0.037 mmol) and C3H5N(C2H4CO2Me)2 (0.22 g, 0.93 mmol)
at 40 ꢁC Method (C): Reaction of C2H3CO2Me (0.13 g, 1.44 mmol) and
30 (0.15 g, 0.026 mmol) yielded 21 as a yellowish oil (0.23 g, 86%) as
described for 19 (method C).
1H NMR (CDCl3):
d
ꢀ0.10 (s, 18H, MeSi), ꢀ0.07 (s, 9H, MeSi),
ꢀ0.04 (s, 36H, MeSi), 0.55 (m, 78H, SiCH2), 1.31 (m, 42H, CH2), 1.52
(d, J¼7.9 Hz, 48H, CH2CHCH2), 1.75 (m, 6H, OCH2CH2), 3.88 (t,
J¼6.3 Hz, 6H, OCH2), 4.84 (m, 48H, CH]CH2), 5.74 (m, 24H, CH]
1H NMR (CDCl3):
d
ꢀ0.12 (s.a., 54H, MeSi), ꢀ0.07 (s, 144H,
Me2Si), 0.38 (m, 48H, SiCH2), 0.52 (m, 174H, SiCH2), 1.26 (m, 84H,
CH2), 1.38 (m, 54H, CH2), 1.75 (m, 6H, OCH2CH2), 2.45 (m, 144H,
CH2N), 2.74 (s.a., 98H, CH2CO), 3.63 (s, 144H, OMe), 3.87 (s.a., 6H,
CH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
d
ꢀ5.7 (MeSi), ꢀ5.0
(MeSi), 13.9 (CH2Si), 17.9, 18.2, 18.5, 18.8, 18.9 (CH2), 20.6
(OCH2CH2CH2), 21.5 (CH2CH]CH2), 33.3 (OCH2CH2), 67.7 (OCH2),
93.6 (C6H3 (CH)), 113.0 (CH]CH2), 134.9 (CH]CH2), 160.9 (i-C6H3);
OCH2), 6.00 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
d
ꢀ4.8 (MeSi),
ꢀ3.3 (Me2Si), 12.8 (SiCH2), 14.1 (SiCH2), 18.4e20.5 (CH2), 32.3
(NCH2), 33.6 (OCH2CH2), 49.2 (CH2CO), 51.6 (OMe), 57.4 (CH2N),
67.8 (OCH2), 93.6 (C6H3 (CH)), 160.9 (i-C6H3), 172.8 (CO); 29Si NMR
29Si NMR (CDCl3):
d
0.1 (MeSi), 0.9 (MeSi), 1.7 (MeSi). [MþNa]þ:
2962.9. Anal. Calcd C165H318O3Si21 (2940.08 g/mol): C, 67.41; H,
10.90; Obt.: C, 66.56; H, 10.87.
(CDCl3):
d
0.9, 1.8 (MeSi), 1.9 (Me2Si). Anal. Calcd
C477H966N24O99Si45 (9886.72 g/mol): C, 57.95; H, 9.85; N, 3.40;
Obt.: C, 57.09; H, 10.10; N, 3.63.
4.2.20. G1O3(C2H4CO2Me)12 (19). Method (A): Following the pro-
cedure described for compound 16, compound 19 was obtained as
a colorless oil (0.32 g, 61%) from the reaction of 1,3,5-(HO)3C6H3
(0.027 g, 0.21 mmol), 9 (0.55 g, 0.65 mmol), K2CO3 (0.18 g,
1.30 mmol), and 18-C-6 (0.017 g, 0.06 mmol) during 4 days in ac-
etone (15 mL). Method (B): Reaction of 25 (1.00 g, 0.95 mmol) and
C3H5N(C2H4CO2Me)2 (1.44 g, 6.08 mmol) in THF (5 mL) in the
presence of Karstedt’s catalyst (3% mol) was stirred overnight at
40 ꢁC. Next, THF was added (15 mL), the solution was filtered
through active carbon and the volatiles were removed under vac-
uum. The remaining oil was washed with cold hexane (10 mL)
obtaining compound 19 as a pale yellow oil (2.14 g, 91%). Method
(C): C2H3CO2Me (0.25 g, 2.85 mmol) was added to a solution of 28
(0.25 g, 0.18 mmol) in methanol (5 mL) and stirred at room tem-
perature for 16 h. Afterward, the volatiles were removed under
vacuum and the residue was washed with cold hexane (5 mL)
yielding 19 as a yellowish oil (0.39 g, 90%).
4.2.23. G1O3(SiCl)6 (22). Following the procedure described for
compound 7, compound 22 was obtained as a colorless oil (1.77 g,
95%) from the reaction of 16 (1.01 g, 1.51 mmol) and HSiMe2Cl
(1.46 g, 0.015 mol).
1H NMR (CDCl3): ꢀ0.05 (s, 9H, MeSi), 0.38 (s, 36H, Me2SiCl), 0.58
(m, 18H, SiCH2), 0.86 (m, 12H, CH2SiCl), 1.42 (m, 18H, CH2), 1.78 (m,
6H, OCH2CH2), 3.88 (t, J¼6.6 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C
NMR{1H} (CDCl3): ꢀ5.1 (MeSi), 1.9 (Me2SiCl), 13.6 (SiCH2), 17.7
(CH2), 17.9 (CH2), 20.5 (OCH2CH2CH2), 23.5 (CH2SiCl), 33.1
(OCH2CH2), 67.5 (OCH2), 93.7 (C6H3 (CH)), 160.9 (i-C6H3); 29Si NMR
(CDCl3): 2.1 (MeSi), 31.1 (Me2SiCl).
4.2.24. G2O3(SiCl)12 (23). Following the procedure described for
compound 7, compound 23 was obtained as a pale yellow oil
(3.41 g, 95%) from the reaction of 17 (2.00 g, 1.40 mmol) and HSi-
Me2Cl (2.71 g, 0.029 mol).
1H NMR (CDCl3):
d
ꢀ0.09 (s, 9H, MeSi), ꢀ0.07 (s, 36H, Me2Si),
0.40 (m, 12H, SiCH2), 0.53 (m, 30H, SiCH2), 1.27 (m, 12H, CH2), 1.36
(m, 18H, CH2), 1.75 (m, 6H, OCH2CH2), 2.39 (m, 12H, CH2N), 2.41 (t,
J¼7.3 Hz, 24H, CH2N), 2.74 (t, J¼7.3 Hz, 24H, CH2CO), 3.64 (s, 36H,
OMe), 3.87 (t, J¼6.6 Hz, 6H, OCH2), 6.03 (s, 3H, C6H3); 13C NMR{1H}
1H NMR (CDCl3): ꢀ0.07 (s, 18H, MeSi), ꢀ0.01 (s, 9H, MeSi),
0.38 (s, 72H, Me2SiCl), 0.54 (m, 54H, SiCH2), 0.86 (m, 24H,
CH2SiCl), 1.28 (m, 12H, CH2), 1.42 (m, 30H, CH2), 1.77 (m, 6H,
OCH2CH2), 3.87 (t, J¼6.6 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C
NMR{1H} (CDCl3): ꢀ5.0 (MeSi), ꢀ4.8 (MeSi), 1.9 (Me2SiCl), 13.9
(SiCH2), 17.7, 18.1 (CH2), 18.5, 18.7, 18.8 (CH2), 20.6 (OCH2CH2CH2),
23.5 (CH2SiCl), 33.3 (OCH2CH2), 67.7 (OCH2), 93.7 (C6H3 (CH)),
160.9 (i-C6H3); 29Si NMR (CDCl3): 1.0 (MeSi), 2.0 (MeSi), 31.2
(Me2SiCl).
(CDCl3):
d
ꢀ5.1 (MeSi), ꢀ3.3 (Me2Si), 12.8 (SiCH2), 13.9 (SiCH2), 18.4,
18.6y 20.1 (CH2), 20.5 (OCH2CH2CH2), 21.5 (CH2CH2N, 32.5
(CH2CO)), 33.7 (OCH2CH2), 49.2 (CH2N), 51.6 (OMe), 57.5 (CH2N),
67.7 (OCH2), 93.6 (C6H3 (CH)), 160.9 (i-C6H3), 173.1 (CO); 29Si NMR
(CDCl3):
d
1.6 (MeSi), 1.9 (Me2Si). [MþH]þ: 2404.5. Anal. Calcd

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J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
4.2.25. G3O3(SiCl)24 (24). Following the procedure described for
compound 7, compound 24 was obtained as a yellowish oil (4.21 g,
95%) from the reaction of 18 (2.50 g, 0.85 mmol) and HSiMe2Cl
(3.28 g, 0.034 mol).
ꢀ5.1 (MeSi), ꢀ3.3 (Me2Si),12.3 (NCH2CH2CH2),13.8 (SiCH2),18.4,18.6,
20.0 (CH2), 20.5 (OCH2CH2CH2), 33.2 (OCH2CH2), 45.6 (NCH2), 67.6
(OCH2), 93.7 (C6H3 (CH)), 160.9 (i-C6H3); 29Si NMR (CDCl3): 1.8
(MeSi), 2.1 (Me2Si). Anal. Calcd C69H156N6O3Si9 (1370.78 g/mol): C,
60.46, H, 11.47, N, 6.13; Obt.: C, 60.91, H, 11.26, N, 5.86.
1H NMR (CDCl3): ꢀ0.09 (s, 27H, MeSi), ꢀ0.07 (s, 36H, MeSi), 0.38
(s, 144H, Me2SiCl), 0.54 (m, 126H, SiCH2), 0.86 (m, 48H, CH2SiCl),
1.25 (m, 36H, CH2), 1.42 (m, 54H, CH2), 1.77 (m, 6H, OCH2CH2), 3.87
(t, J¼6.6 Hz, 6H, OCH2), 6.03 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
ꢀ5.0, ꢀ4.8 (MeSi), 1.9 (Me2SiCl), 13.9 (CH2Si), 17.7, 18.1, 18.5, 18.8,
18.9, 19.1 (CH2), 20.6 (OCH2CH2CH2), 23.5 (CH2SiCl), 33.4
(OCH2CH2), 67.7 (OCH2), 93.6 (C6H3 (CH)), 160.9 (i-C6H3); 29Si NMR
(CDCl3): 1.0, 1.6 (MeSi), 31.1 (Me2SiCl).
4.2.30. G2O3(NH2)12 (29). Following the procedure described for
compound 28, compound 29 was obtained as a colorless oil (0.47 g,
72%) from the reaction of 26 (0.50 g, 0.23 mmol) and C3H5NH2
(0.32 g, 5.59 mmol).
1H NMR (CDCl3): ꢀ0.11 (s,18H, MeSi), ꢀ0.09 (s, 9H, MeSi), ꢀ0.07 (s,
72H, Me2SiH), 0.43 (m, 26H, CH2), 0.54 (m, 72H, CH2), 1.21 (s, 24H,
NH2), 1.28 (m, 36H, CH2), 1.38 (m, 30H, CH2), 1.74 (m, 6H, OCH2CH2),
2.63 (t, J¼7.1 Hz, 24H, CH2N), 3.85 (t, J¼6.3 Hz, 6H, OCH2), 6.04 (s, 3H,
C6H3); 13C NMR{1H} (CDCl3): ꢀ4.9(MeSi), ꢀ4.7 (MeSi), ꢀ3.3 (Me2Si),
12.3 (SiCH2), 13.8 (SiCH2), 18.4, 18.6, 18.8, 20.0, 20.1 (CH2), 20.6
(OCH2CH2CH2), 28.3 (CH2CH2N), 33.3 (OCH2CH2), 45.7 (CH2N), 67.6
(OCH2), 93.7 (C6H3 (CH)),160.9 (i-C6H3); 29Si NMR (CDCl3): 0.9 (MeSi),
1.7 (MeSi),1.9(Me2Si). Anal. Calcd C141H330N12O3Si21 (2832.00 g/mol):
C, 59.80; H, 11.75; N, 5.94; Obt.: C, 60.92; H, 10.03; N, 5.44.
4.2.26. G1O3(SiH)6 (25). Following the procedure described for
compound 8, compound 25 was obtained as a colorless oil (1.18 g,
80%) from the reaction of 22 (1.77 g, 1.43 mmol) and LiAlH4
(6.45 mmol).
1H NMR (CDCl3):
d
ꢀ0.08 (s, 9H, MeSi), 0.04 (d, J¼4.2 Hz, 36H,
Me2SiH), 0.55 (m, 18H, SiCH2), 0.63 (m, 12H, CH2SiH), 1.25 (m, 18H,
CH2), 1.77 (m, 6H, OCH2CH2), 3.82 (m, 6H, SiH), 3.88 (t, J¼6.6 Hz, 6H,
OCH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
d
ꢀ5.1 (MeSi), ꢀ4.4
(Me2SiH), 13.7 (SiCH2), 18.0, 18.8y 18.9 (CH2), 20.5 (OCH2CH2CH2),
33.2 (OCH2CH2), 67.6 (OCH2), 93.8 (C6H3 (CH)), 161.0 (i-C6H3); 29Si
4.2.31. G3O3(NH2)24 (30). Following the procedure described for
compound 28, compound 30 was obtained as a colorless oil (0.24 g,
36%) from the reaction of 27 (0.50 g, 0.12 mmol) and C3H5NH2
(0.62 g, 5.50 mmol).
NMR (CDCl3):
d
ꢀ14.0 (Me2SiH), 1.9 (MeSi). MS [MþH]þ: 1027.68.
Anal. Calcd C51H114O3Si9 (1028.22 g/mol): C, 59.57; H, 11.18; Obt.: C,
59.89; H, 11.53.
1H NMR (CDCl3): ꢀ0.11 (s.a., 54H, MeSi), ꢀ0.07 (s, 144H,
Me2Si), 0.52 (m, 222H, SiCH2), 1.21e1.50 (m, 186H, NH2, CH2), 1.74
(m, 6H, OCH2CH2), 2.63 (t, J¼7.1 Hz, 48H, CH2N), 3.85 (t,
J¼6.3 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
ꢀ4.9 (MeSi), ꢀ3.3 (Me2Si), 12.8 (CH2CH2CH2N), 14.1 (SiCH2),
17.9e20.6 (CH2), 27.1 (CH2CH2N), 33.4 (OCH2CH2), 45.1 (CH2N),
67.8 (OCH2), 93.7 (C6H3 (CH)), 161.0 (i-C6H3); 29Si NMR (CDCl3):
0.9 (MeSi), 1.7 (MeSi), 1.9 (Me2Si). Anal. Calcd C285H678N24O3Si45
(5754.44 g/mol): C, 59.49; H, 11.88; N, 5.84; Obt.: C, 58.50; H,
11.67; N, 5.34.
4.2.27. G2O3(SiH)12 (26). Following the procedure described for
compound 8, compound 26 was obtained as a colorless oil (0.95 g,
79%) from the reaction of 23 (1.45 g, 0.57 mmol) and LiAlH4
(5.10 mmol).
1H NMR (CDCl3):
d
ꢀ0.10 (s,18H, MeSi), ꢀ0.08 (s, 9H, MeSi), 0.03 (d,
J¼4.2 Hz, 72H, Me2SiH), 0.55 (m, 54H, SiCH2), 0.63 (m, 24H, CH2SiH),
1.35 (m, 42H, CH2), 1.77 (m, 6H, OCH2CH2), 3.82 (m, 12H, SiH), 3.88 (t,
J¼6.6 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
ꢀ5.1
d
(MeSi), ꢀ5.0 (MeSi), ꢀ4.4 (Me2SiH), 13.9 (SiCH2), 18.2, 18.5, 18.8y 19.0
(CH2), 20.5 (OCH2CH2CH2), 33.3 (OCH2CH2), 67.7 (OCH2), 93.7 (C6H3
(CH)), 160.9 (i-C6H3); 29Si NMR (CDCl3):
d
ꢀ14.2 (Me2SiH), 0.8 (MeSi),
4.2.32. G2O3(SiCl2)6 (31). Following the procedure described for
compound 1, compound 31 was obtained as a colorless liquid
(4.20 g, 94%) from 17 (2.20 g, 3.30 mmol) and HSiMeCl2 (3.87 g,
0.033 mol).
1.9 (MeSi). [MþH]þ: 2147.4. Anal. Calcd C105H246O3Si21 (2146.87 g/
mol): C, 58.74; H, 11.55; Obt.: C, 58.29; H, 11.53.
1H NMR (CDCl3): ꢀ0.03 (s, 9H, MeSi), 0.53 (m, 6H, SiCH2), 0.66
(m, 12H, SiCH2), 0.75 (s, 18H, MeSiCl2), 1.16 (m, 12H, CH2SiCl2), 1.50
(m, 18H, CH2), 1.76 (m, 6H, OCH2CH2), 3.89 (t, J¼6.6 Hz, 6H, OCH2),
6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3): ꢀ5.2 (MeSi), 5.5 (MeSiCl2),
13.4 (SiCH2), 17.4 (CH2), 20.4 (OCH2CH2CH2), 25.9 (CH2SiCl2), 33.1
(OCH2CH2), 67.5 (OCH2), 93.8 (C6H3 (CH)), 160.9 (i-C6H3); 29Si NMR
(CDCl3): 2.0 (MeSi), 32.2 (MeSiCl2).
4.2.28. G3O3(SiH)24 (27). Following the procedure described for
compound 8, compound 27 was obtained as a colorless oil (0.93 g,
74%) from the reaction of 24 (1.50 g, 0.29 mmol) and LiAlH4
(5.00 mmol).
1H NMR (CDCl3):
d
ꢀ0.10 (s.a., 54H, MeSi), 0.03 (d, J¼4.2 Hz,
144H, Me2SiH), 0.58 (m, 174H, SiCH2), 1.35 (m, 90H, CH2), 1.77 (m,
6H, OCH2CH2), 3.82 (m, 30H, SiH y OCH2), 6.03 (s, 3H, C6H3); 13C
NMR{1H} (CDCl3):
d
ꢀ5.0 (MeSi), ꢀ4.3 (Me2SiH), 13.9 (CH2Si), 18.2,
18.5, 18.8, 18.9 (CH2), 20.6 (OCH2CH2CH2), 33.2 (OCH2CH2), 67.7
(OCH2), 94.5 (C6H3 (CH)), 160.9 (i-C6H3); 29Si NMR (CDCl3):
4.2.33. G3O3(SiCl2)12 (32). Following the procedure described for
compound 1, compound 32 was obtained as a colorless liquid
(4.26 g, 95%) from 18 (2.30 g, 1.61 mmol) and HSiMeCl2 (3.90 g,
0.034 mol).
d
ꢀ14.2
(Me2SiH),1.0,1.2 (MeSi). Anal. Calcd C213H510O3Si45 (4384.17 g/mol):
1H NMR (CDCl3): ꢀ0.07 (s, 9H, MeSi), ꢀ0.05 (s, 18H, MeSi), 0.59
(m, 54H, SiCH2), 0.75 (s, 36H, MeSiCl2), 1.16 (m, 24H, CH2SiCl2), 1.29
(m, 18H, CH2), 1.50 (m, 24H, CH2), 1.76 (m, 6H, OCH2CH2), 3.87 (t,
J¼6.6 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3): ꢀ5.1
(MeSi), 5.5 (MeSiCl2), 13.8 (CH2Si), 17.3, 17.5, 18.5, 18.6, 18.8 (CH2),
20.6 (OCH2CH2CH2), 25.9 (CH2SiCl2), 33.3 (OCH2CH2), 67.7 (OCH2),
93.7 (C6H3 (CH)), 161.0 (i-C6H3); 29Si NMR (CDCl3): 1.8 (MeSi), 32.1
(MeSiCl2).
C, 58.35; H, 11.73; Obt.: C, 58.85; H, 10.97.
4.2.29. G1O3(NH2)6 (28). C3H5NH2 (0.37 g, 6.42 mmol) was added
to a THF solution (3 mL) of compound 25 (0.50 g, 0.49 mmol) in the
presence of Karstedt catalyst (3% mol) and stirred at 120 ꢁC for 3
days into a sealed ampoule. The volatiles were removed under
vacuum, CH2Cl2 was added to the residue and the solution was
filtered through active carbon. After removal of volatiles compound
28 was obtained as a yellowish oil (0.59 g, 89%).
1H NMR (CDCl3): ꢀ0.09 (s, 9H, MeSi), ꢀ0.06 (s, 36H, Me2SiH), 0.48
(m, 12H, SiCH2), 0.54 (m, 30H, SiCH2), 1.29 (m, 18H, CH2), 1.40 (m,
24H, NH2, CH2), 1.74 (m, 6H, OCH2CH2), 2.63 (t, J¼7.1 Hz, 12H, CH2N),
3.87 (t, J¼6.3 Hz, 6H, OCH2), 6.04 (s, 3H, C6H3); 13C NMR{1H} (CDCl3):
Acknowledgements
This work has been supported by grants from Fondos de
Investigación Sanitaria (FIS) of Ministerio de Sanidad y Consumo

J. Sánchez-Nieves et al. / Tetrahedron 66 (2010) 9203e9213
9213
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