Synthesis of azacrown ethers modified with side-chains containing germanium

Article abstract of DOI:10.1016/S0022-328X(01)01054-3

The reaction between ethanolamine (4) and tri- or tetraethylene tosylate (5) and (13) gave 9- and 12-membered monoazacrowns with a -CH₂CH₂OH residue on nitrogen, A-OH and B-OH, together with 18- and 24-membered diazacrown ethers with the same substituent on nitrogen, E-OH and F-OH. If 2-(2-aminoethoxy)ethanol (12) was used in the reaction described above, instead of 4, the final products, G-OH and H-OH, and K-OH and L-OH, have a longer side chain, -CH₂CH₂OCH₂CH₂OH, on nitrogen (Route 1). A series of reactions involving bromoethanol (6) and diethanolamine (9) formed, with 5 or 13, 18- and 24-membered monoazacrowns with the shorter substituent as described above, a 15-membered monoazacrown ether C-OH and an 18-membered D-OH. If 2-(2-chloroethoxy)ethanol (14) is used instead of 6, I-OH and J-OH are obtained (Route 2′). All these hydroxy azacrown ethers were made to react with 3-trimethylgermylpropionic acid (18) to give the corresponding germanium-containing A-L. A preliminary investigation was carried out on the cation transport capability of these germanium-containing azacrown ethers to observe whether germanium might enhance their cation transporting capability.

Full text of DOI:10.1016/S0022-328X(01)01054-3

Journal of Organometallic Chemistry 636 (2001) 108–123
www.elsevier.com/locate/jorganchem
Synthesis of azacrown ethers modified with side-chains containing
germanium
Ryoko Suzuki a, Takashi Matsumoto a, Katsumi Tanaka a, Yoshito Takeuchi a,*,
Tamotsu Taketomi b
a Department of Chemistry, Faculty of Science, Kanagawa Uni6ersity, 2946 Tsuchiya, Hiratsuka-shi 259-1293, Japan
b Di6ision of Neuro-Aging, Research Center on Aging and Adaptation, Shinshu Uni6ersity School of Medicine, Matsumoto-shi 390-8621, Japan
Received 9 March 2001; accepted 24 May 2001
Abstract
The reaction between ethanolamine (4) and tri- or tetraethylene tosylate (5) and (13) gave 9- and 12-membered monoazacrowns
with a ꢀCH2CH2OH residue on nitrogen, A-OH and B-OH, together with 18- and 24-membered diazacrown ethers with the same
substituent on nitrogen, E-OH and F-OH. If 2-(2-aminoethoxy)ethanol (12) was used in the reaction described above, instead of
4, the final products, G-OH and H-OH, and K-OH and L-OH, have a longer side chain, ꢀCH2CH2OCH2CH2OH, on nitrogen
(Route 1). A series of reactions involving bromoethanol (6) and diethanolamine (9) formed, with 5 or 13, 18- and 24-membered
monoazacrowns with the shorter substituent as described above, a 15-membered monoazacrown ether C-OH and an 18-membered
D-OH. If 2-(2-chloroethoxy)ethanol (14) is used instead of 6, I-OH and J-OH are obtained (Route 2%). All these hydroxy azacrown
ethers were made to react with 3-trimethylgermylpropionic acid (18) to give the corresponding germanium-containing A–L. A
preliminary investigation was carried out on the cation transport capability of these germanium-containing azacrown ethers to
observe whether germanium might enhance their cation transporting capability. © 2001 Published by Elsevier Science B.V.
Keywords: Cation transport; Diazacrown ether; Esterification; H-tube test; Hydrogermylation; Monoazacrown ether; Organogermanium com-
pounds
1. Introduction
capability [4]. We have also shown that 1,8-dichloro-
1,8-dimethyl-1,8-digermacyclotetradecane (2) [5] and
1,12-dichloro-1,12-dimethyl-1,12-digermacyclo-doco-
sane (3) [6] transport chloride anions selectively.
Ever since the commencement of the chemistry of
crown ethers [1], their capability to capture and trans-
port cations with sizes comparable to the size of the
crown cavity has attracted considerable attention. Aza-
crown ethers have been known to possess the same
capability [2], and in a way, are more suitable than
crown ethers themselves in that it is possible to intro-
duce a variety of side chains on nitrogen so that the
modification of the nature of the cavity is more feasible.
In this regard, many reports have been published on the
synthesis and cation transport experiments [3].
Meanwhile, it was also known that some cyclic com-
pounds containing Group 14 element(s) such as silicon
or tin exhibit anion capturing/transporting capabilities.
One example is the 1,1,5,5,9,9-hexamethyl-1,5,9-trisila-
cyclododecane (1), which showed the anion transport
* Corresponding author.
E-mail address: yoshito@chem.kanagawa.u.ac.jp (Y. Takeuchi).
0022-328X/01/$ - see front matter © 2001 Published by Elsevier Science B.V.
PII: S0022-328X(01)01054-3

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
109
It occurred to us that if the cation capturing/trans-
porting property of azacrown ethers and the anion
capturing/transporting property of organogermanium
compounds could be combined, then the cation captur-
ing/transporting property of the azacrown might be
affected, and hopefully enhanced, by the presence of
germanium. The latter might capture/transport the
counteranion of the cation that is trapped by the aza-
crown ethers. With this prospect in mind, we decided to
prepare a series of azacrown ethers that have side-
chains modified with germanium.
difficult to obtain an analytically pure sample because
of some contamination which was difficult to remove.
For method (ii), some complication is inevitably in-
volved in most cases, probably because of the high
reactivity of the organolithium reagent.
Finally, we found that the last method is the one of
choice because the reaction in general is cleaner than
the other two methods, and hence the yield is
reasonable.
2.2. Synthesis of hydroxyazacrown ethers
The idea of ditopic ligands which capture/transport
cations and anions simultaneously is not new. For
instance, Tasker et al. reported some ligands that cap-
ture transition metal cation and its counteranion simul-
Yet another advantage of using method (iii) is that
the preparation of azacrown ethers having a terminal
hydroxy group on nitrogen as the side chain is well
known [9,10]. For the preparation of such hydroxyaza-
crown ethers, we have chosen two slightly different
routes. In both the routes, the ring component is a
polyethyleneglycol (as the tosylate) and the nucleophilic
displacement occurring at the two termini of these is
the key reaction for the ring closure.
In Route 1, a hydroxy-amine is used as the nitrogen
source and in this case the nucleophile is the nitrogen.
The side chain on nitrogen of the azacrown ethers
necessarily originates from the substituent on the nitro-
gen of the hydroxy-amine. By choosing the substituent,
azacrown ethers with different side chains on nitrogen
can be prepared.
taneously [7]. Beer et al. reported
a
tripod
tris(amidobenzo-15-crown-5) sodium ion and an anion
such as halide anions simultaneously [8]. For these
ligands, and other ditopic ligands, the binding sites are
usually a quaternary ammonium salt or an amide moi-
ety; to the best of our knowledge, the idea of using
germanium or any other Group 14 elements as the
binding site of anions in the ditopic ligand is not
known.
2. Results and discussion
2.1. Strategy of synthesis
In Route 2, a dihydroxy-amine is used as the nitro-
gen source and the two oxygen atoms of the hydroxy
group will act as the nucleophiles that attack the two
termini of glycol. The side chain on nitrogen of the
dihydroxy-amine is necessarily the substituent on nitro-
gen of the azacrown ethers. It is difficult to introduce
the substituent after the ring closure, and consequently
a dihydroxy-amine with a substituent on nitrogen must
be used (Route 2%). Here again, by choosing the sub-
stituents, azacrown ethers with different side chains on
nitrogen can be prepared. The essence of Routes 1, 2
and 2% are shown in Scheme 1 where the wavy line
indicates alkyl or alkyloxy residues.
Since the synthesis of azacrown ethers is well docu-
mented, the crucial point of synthesis of our target
molecules is the introduction of a germanium moiety
into the molecule. There are several methods available
to achieve the incorporation of germanium:
1. Hydrogermylation of an alkene (Eq. (1)):
R−CH=CH2+R1R2R3Ge−H
“R−CH2−CH2GeR1R2R3
(1)
2. Reaction between lithio derivative of an
a
organogermanium compound and a haloalkane (Eq.
(2)):
Typical examples of the preparation of hydroxyaza-
crown ethers are shown in the following schemes. Thus,
by Route 1, a mixture of ethanolamine (4) and tri-
R−X+R1R2R3Ge−Li“R−Ge R1R2R3+LiX
(2)
3. Esterification of an alcohol with a germanium-con-
taining carboxylic acid or its derivative (Eq. (3)):
(3)
Initially, we intended to synthesize the desired aza-
crown ethers by hydrogermylation. Although the at-
tempt was successful, the yield was low, and it was
Scheme 1. The formation of azacrown ethers.

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R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
This method is a modification of the one reported by
Newkombe and Marsden [12]. Although many other
methods have been reported, we almost exclusively used
this method to prepare the monoazacrown ethers.
For synthesizing other azacrown ethers, one can use
the other amine sources or ring sources. Thus, if te-
traethyleneglycol ditosylate (13) is used instead of 5,
azacrown ethers with larger ring size can be prepared.
If 2-(2-aminoethoxy)ethanol (12) is used instead of 4,
an azacrown ether with a longer substituent on nitrogen
will be obtained. As shown in Scheme 4, the reaction
between 12 and 13 gave the 12-membered hydroxy
monoazacrown ether (H-OH) and the 24-membered
dihydroxy diazacrown ether (L-OH), both of which
have a longer side-chain on nitrogen.
The same strategy can be applied to Route 2. Thus,
a combined use of 2-(2-chloroethoxy)ethanol (14) in-
stead of 6, and of 13 instead of 5 gave the 18-membered
hydroxymonoazacrown (J-OH) via its pyranyl ether
(17) (Scheme 5).
Thus, akin to the synthesis of the azacrown ether
skeleton, we used only two methods modified from the
methods outlined in Refs. [11,12]. The details of the
synthesis will be given in Section 3.
Scheme 2. Synthesis of hydroxyazacrown ether via Route 1.
ethyleneglycol ditosylate (5) was heated in MeCN in the
presence of Na2CO3 to form a mixture of 9-membered
N-(2-hydroxyethyl)-4-aza-9-crown-3 (A-OH) and 18-
membered
N,N%-bis(2-hydroxyethyl)-4,13-diaza-18-
crown-6 (E-OH), which was separated by gel
permeation chromatography (GPC) (Scheme 2). This
route to E-OH is a modification of the method reported
by Gatto and Gokel [11] although they used diiodide
instead of ditosylate.
In practice, Route 2 is a little complicated because
the NH function of the dihydroxy amine must be
protected during the ring closure, and the protecting
procedure was selected such that the protecting group
would eventually be the side-chain on the nitrogen with
the terminal hydroxy group (Route 2%). Thus, 2-bro-
moethanol (6) was treated with 1,2-dihydropyran (7) to
give 2-bromoethylpyranyl ether (8). The pyranyl ether 8
was made to react with diethanolamine (9) to form the
necessary nitrogen source, N-(2-pyranyloxyethyl)-
diethanolamine (10). The cyclization proceeded
smoothly between 10 and 5 to give the pyranyloxyethyl
azacrown ether (11). Hydrolysis of 11 with aqueous
(aq.) HCl gave the 15-membered N-(2-hydroxyethyl)-4-
aza-15-crown-5 (C-OH) (Scheme 3).
2.3. Incorporation of germanium moiety into azacrown
ethers
We have chosen 3-(trimethylgermyl)propionic acid
(CH3)3GeCH2CH2COOH (18), as the carboxylic acid to
be used in Eq. (3). Hydrogermylation of acrylic acid
Scheme 3. Synthesis of azacrown ether via Route 2%.
Scheme 4. Synthesis of hydroxyazacrown ethers with longer side chain on nitrogen via Route 1.

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
111
2.4. Attempted hydrogermylation
Hydrogermylation is one of the most common reac-
tions for incorporating germanium into organic com-
pounds if the precursor, an appropriate alkene, is easily
obtained. In fact, the reaction between allyl bromide
(21) and 9 gave allyldiethanolamine (22), which was
made to react with 5 to give N-allyl-4-aza-15-crown-5
(23). The hydrogermylation of 23 with triphenylger-
mane (24) in the presence of a catalytic amount of
H2PtCl6 gave the desired product, N-(3-triphenyl-
germylpropyl)-4-aza-15-crown-5 (25) as shown in
Scheme 7. The yield was low, and it was extremely
difficult to obtain an analytically pure sample from the
reaction mixture.
Scheme 5. Synthesis of hydroxyazacrown ethers with longer side
chain on nitrogen via Route 2%.
2.5. Characterization
The characterization of the prepared hydroxy aza-
crown ethers (A-OH–L-OH) and their germaesters (A–
1
L) was carried out mostly based on H- and 13C-NMR
spectra together with mass spectrometric analysis.
For instance, the characterization of the 18-mem-
bered monoazacrown D-OH and D, 18-membered di-
azacrowns E-OH and E, and the 24-membered
diazacrowns F-OH and F will be described.
Mass spectra of all alcohols A-OH–L-OH and their
precursors were recorded in the electron impact (EI)
mode. All of these showed molecular ion peaks as
indicated in Section 3.
Scheme 6. Incorporation of germanium with acid chloride.
with trichlorogermane HGeCl3 gives 3-trichlorogermyl-
propionic acid (19) and the subsequent Grignard reac-
tion of 19 with methyl magnesium iodide gives 18 (Eq.
4), e.g.
However, for germanium compounds A–L, the EI
mode mass spectra are not always very clear-cut,
mostly because of excessive fragmentation. In particu-
lar, the characteristic pattern owing to the isotope
distribution of germanium was largely obscured. Some
ten years ago, matrix-assisted laser desorption ioniza-
tion (MALDI) mass spectrometry [13] was introduced
for the analysis of high molecular weight natural prod-
ucts, such as proteins. A substantial improvement was
achieved by a combination of MALDI and time-of-
flight (TOF) techniques [14] and recently, delayed ion
extraction (DE) technique was introduced to MALDI-
TOF mass spectrometry [15], which improved the reso-
lution and accuracy of mass spectra such that the
isotopically resolved peaks could be observed. It oc-
curred to us that this DE MALDI-TOF technique
might be a powerful tool for the analysis of organoger-
manium compounds by showing the isotopic distribu-
tion of germanium clearly.
CH2=CHCOOH+HGeCl3
“Cl3GeCH2CH2COOH (19)
Cl3GeCH2CH2COOH+3CH3MgI
“(CH3)3GeCH2CH2COOH (18)+3MgClI
(4)
Initially we used 3-trimethylgermylpropionyl chloride
(CH3)3GeCH2CH2COCl (20), for the esterification pro-
cess (Schotten–Baumann reaction). However, it turned
out that the reaction proceeded smoothly, but the aza-
crown ethers formed the hydrogen chloride salt, which
requires neutralization with Na2CO3, consequently
making the following separation/purification proce-
dures more tedious (Scheme 6).
Incorporation of the germanium moiety was achieved
by the reaction of the hydroxyazacrown ethers and 18
in CHCl3 in the presence of 4-aminopyridine and dicy-
clohexylcarbodiimide (DCC). The yields are generally
reasonable.
The whole DE MALDI-TOF mass spectra and the
expansion of the [M+H]+ peak of D are shown as an
example of compounds containing one germanium
atom in Fig. 3a and b, respectively. Fig. 4a and b
shows, respectively, the whole DE MALDI-TOF mass
spectra and the expansion of the [M+H]+ peak of E
as an example of compounds containing two germa-
All trimethylgermylpropionates of monoazacrown
ethers are listed in Fig. 1, while the similar derivatives
of the diazacrowns are given in Fig. 2.

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R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
1
The assignment of H-NMR spectra of A, B and C,
and their precursors can be made in a similar manner.
The assignment for azacrowns with longer side chain
also follows a similar strategy.
nium atoms. The usefulness of DE MALDI-TOF spec-
tra in characterizing organogermanium compounds is
obvious.
In 1H-NMR spectra, all the azacrown ethers exhibit a
large multiplet centered on l 3.60–3.65 owing to the
ring protons adjacent to oxygen. The signal of the
ꢀCH2OH methylene of the side chain is also in this
region. There are two types of methylene group adja-
cent to nitrogen: one is in the ring and the other in the
side chain. Based on the intensity, it is clear that the
ring methylene is in the low-field region.
The assignment of 13C-NMR spectra is also more or
less straightforward. The methylene carbons adjacent to
oxygen resonate at around l 70 while those adjacent to
nitrogen are around l 54–57. The signal of the
ꢀCH2OH methylene carbon is at the lower field (ca. l
59) compared with ring methylene, and on esterification
it moves to low field (l 72). It is easy to identify the
carbon nuclei belonging to the side chain. The whole
discussion is summarized in Fig. 6.
The assignment of the NMR spectra of azacrown
ethers with longer side chains is exemplified by the case
of K-OH and K. The ring- and side-chain methylene
protons adjacent to oxygen have as much the same
chemical shifts as their monoaza analogs. The ring- and
side-chain methylene protons adjacent to nitrogen have
slightly different chemical shifts for K-OH, which are
degenerate for K. The same is true for their 13C-NMR
All the esters D, E and F exhibited a feature common
to the ester side chain. The strong signal at very high
field is certainly because of the three methyl groups
bonded to germanium. The methylene proton bonded
to germanium comes next, and in esters, the two types
of methylene group adjacent to nitrogen are degenerate.
The signal of the ring methylene adjacent to oxygen is
as much the same as that of the precursor. Finally, the
ꢀCH2OCOꢀ methylene signal appears at the lowest
field. The discussion above is summarized in Fig. 5.
Fig. 1. Prepared monoazacrowns with germanium-containing side-chains.

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
113
Fig. 2. Prepared diazacrowns with germanium-containing side-chains.
spectra also; two types of methylene carbons adjacent
to oxygen cannot be differentiated although the shift
values of these carbons adjacent to the nitrogen are
slightly different. Here again the germanium-containing
side chain(s) can be identified easily by NMR spectra.
The results are summarized in Fig. 7.
obtained. Research along this line is in progress in our
laboratory.
2.6. Cation transport experiments
A preliminary series of cation transport experiments
was carried out by the H-tube test for all azacrown
ethers with germanium-containing side chains [16]. The
device used is illustrated in Fig. 8 and the observations
have been summarized below.
3. Experimental
All manipulations were performed under an inert
atmosphere of nitrogen or argon. Dry, oxygen-free
solvents were employed throughout. Diethyl ether was
distilled from sodium before use. Tetrahydrofuran
(THF) and MeCN were dried by LAH and molecular
sieve, respectively.
1. When alkali metal chlorides are used, the cation
transport capability of our azacrown ethers is in
parallel with the conventional azacrown ethers. Thus,
the 15-membered azacrown ethers transport Na+,
and the 18-membered azacrown ethers transport K+.
2. When alkali metal nitrates are used, the 18-membered
azacrown ethers transport K+.
IR spectra were determined with a JASCO FTIR-300
1
spectrometer. H-NMR spectra were determined on a
JEOL EX-400 spectrometer operating at 400 MHz, and
the chemical shifts were reported in l (ppm) with
3. When the transport of K+ by 18-membered azacrown
ethers was measured, the largest amount of trans-
port was observed when the counteranion was
iodide.
However, we have to admit that it is rather difficult
to assess the role of germanium in the cation transport
by azacrown ethers. It will be necessary to prepare the
whole series of azacrown ethers such as 26, the carbon
analog of D, with a carbon atom instead of germanium.
The role of the side-chains carrying the germanium
moiety cannot be assessed before some conclusion can be
Scheme 7. Synthesis of a germaazacrown ether via hydrogermylation.

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R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
Fig. 3. (a) Mass spectrum of D (full). A peak at 504.02 is owing to [M+Na]+. (b) Mass spectrum of D (expansion).
respect to Me4Si. 13C-NMR spectra were determined on
a JEOL EX-400 spectrometer operating at 100 MHz and
the chemical shifts were reported in l (ppm) with respect
to Me4Si. Mass spectra were recorded on JEOL NS-
MP09 mass spectrometer operating in the EI mode at 70
eV or on a PerSeptive Bioystems DE MALDI-TOF mass
spectrometer, Voyager Elite XL. Atomic absorption
spectra were determined with a Hitachi 12-8100 Polar-
ized Zeeman atomic absorption spectrometer.
3.1. N-(2-Hydroxyethyl)-4-aza-9-crown-3 (A-OH) and
N,N%-bis(2-hydroxyethyl)-4,13-diaza-18-crown-6
(E-OH)
A solution of ethanolamine (4) (2.70 g, 44.2 mmol),
triethylenegylcol ditosylate (5) (17.60 g, 38.4 mmol) and

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
115
Na2CO3 (17.68 g, 166.8 mmol) in MeCN (370 ml) was
stirred vigorously under reflux for 24 h. The reaction
mixture was cooled and filtered, and the filtrate was
concentrated in vacuo. The residue was dissolved in
H2O. The aqueous solution was repeatedly extracted
with CHCl3. The combined organic phase was dried
over MgSO4, concentrated in vacuo, and then column
chromatographed (Al2O3) by eluting with CHCl3–2-
propanol=10:1, followed by separation by GPC to
give A-OH (0.89 g, 13.2%) and E-OH (1.34 g, 20.0%)
both as pale yellow oil.
A-OH. 1H-NMR (CDCl3): l 2.79 (t, 2H, chain-
NCH2), 2.84 (t, 4H, ring-NCH2), 3.60 (m, 10H, OCH2,
OH). 13C-NMR (CDCl3): l 55.19 (ring-NCH2), 58.63
(chain-NCH2), 59.01 (CH2OH), 72.80 and 73.09
(CH2O). IR (neat, NaCl, cm−1): 3409. EIMS; m/z (%
Fig. 4. (a) Mass spectrum of E. A peak at 716.97 is owing to [M+Na]+. (b) Mass spectrum of E (expansion).

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R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
B-OH. 1H-NMR (CDCl3): l 2.67 (t, 4H, chain-
CH2N), 2.71 (t, 8H, ring-CH2N), 3.63 (m, 15H, OCH2,
OH). 13C-NMR (CDCl3): l 55.13 (ring-CH2N), 57.02
(chain-CH2N), 59.27 (CH2OH), 69.31, 70.46 and 70.65
(CH2O). IR (neat, NaCl, cm−1): 3388 (s). EIMS; m/z
(% relative intensity): 219 ([M+], 5.8) (C10H21O4N,
219.28).
F-OH. 1H-NMR (CDCl3): l 2.69 (t, 4H, chain-
CH2N) 2.79 (t, 8H, ring-CH2N) 3.60 (m, 30H, OCH2,
OH). 13C-NMR (CDCl3): l 54.62 (ring-CH2N), 57.02
(chain-CH2N), 59.27 (CH2OH), 69.61, 70.36 and 70.58
(CH2O). IR (neat, NaCl, cm−1): 3190. EIMS; m/z (%
relative intensity): 438 ([M+], 5.8) (C20H42O8N2,
438.56).
The alcohols B-OH, C-OH and D-OH were prepared
by the reaction of the corresponding azacrown with
ethylene oxide. The 1H-NMR data reported are in good
agreement with our data [17].
3.3. N-(2-Hydroxyethyl)-4-aza-15-crown-5 (C-OH)
The preparation was carried out by the method
described in the literature [17]. A mixture of 2-bro-
moethanol (6) (6.52 g, 4.98 mmol) and p-toluenesufonic
acid (TsOH) (1.13 g, 5.90 mmol) was added dropwise to
dihydropyran (7) (8.55 g, 102 mmol) at 0 °C and
stirred continuously for 12 h. Aq. NaHCO3 (10%, 100
ml) was added and the mixture was extracted with
CH2Cl2. The organic layer was dried over MgSO4 and
the solvent was removed under reduced pressure. The
residue was distilled in vacuo (80 °C, 8 Torr) to give a
colorless oil of 2-bromoethylpyranyl ether (8) (9.22 g,
82.2%).
Fig. 5. Assignment of 1H-NMR spectra of some azacrown ethers.
1
relative intensity): 175 ([M+], 8.87) (C8H17O3N,
175.23).
8. H-NMR (CDCl3): l 1.52–1.90 (m, 6H, py-CH2),
3.46–3.53 (m, 3H, CH2O), 3.54–4.04 (m, 3H, CH2O)
4.66–4.68 (m, 1H, CH). 13C-NMR (CDCl3): l 19.38
(py-CH2) 25.46 (py-CH2), 30.52 (py-CH2 or CH2Br),
30.96 (py-CH2 or CH2Br), 62.30 (CH2O), 67.55
(CH2O), 98.8 (CH). IR (neat, NaCl, cm−1): 2943.A
mixture of 8 (1.96 g, 9.37 mmol), diethanolamine (9)
(1.02 g, 9.70 mmol) and K2CO3 (1.55 g, 11.2 mmol) was
stirred in DMF (15 ml) for 24 h. DMF was removed
under reduced pressure, and the solid was filtered. The
filtrate was dissolved in CH2Cl2, dried and evaporated.
By distillation in vacuo (140 °C, 2 Torr), a colorless oil
of N-2-(pyranyloxyethyl)diethanolamine (10) (1.32 g,
60.4%) was obtained.
E-OH. 1H-NMR (CDCl3): l 2.64 (t, 4H, chain-
NCH2), 2.75 (t, 8H, ring-NCH2), 3.60 (m, 20H, OCH2,
OH). 13C-NMR (CDCl3): l 55.13 (ring-NCH2), 57.36
(NCH2), 59.38 (CH2OH), 69.81 and 70.65 (CH2O). IR
(neat, NaCl, cm−1): 3425. EIMS; m/z (% relative inten-
sity): 350 ([M+], 10.20) (C16H34O6N2, 350.46).
Gatto and Gokel [11] obtained E-OH by the reaction
of substituted amine and the diiodide as the NaI com-
plex. On the contrary, our method directly yielded the
desired product E-OH.
3.2. N-(2-Hydroxyethyl)-4-aza-12-crown-4 (B-OH)
and N,N%-bis(2-hydroxyethyl)-7,19-diaza-24-crown-8
(F-OH)
10.1H-NMR (CDCl3): l 1.51–1.82 (m, 6H, py-CH2),
2.69–2.73 (m, 6H, NCH2), 3.54–3.94 (m, 10H, CH2O),
4.54–4.57 (m, 1H, CH). 13C-NMR (CDCl3): l 20.52
(py-CH2), 25.26 (py-CH2), 30.92 (py-CH2), 54.31
(CH2N; to be side chain), 57.48 (CH2N; to be ring),
59.73(CH2O; to be ring), 63.83 and 67.01 (CH2O),
100.13 (CH). IR (neat, NaCl, cm−1): w(OH) 3391.
To a suspension of sodium hydride (NaH) (1.09 g,
45.3 mmol) in THF (80 ml), a THF (50 ml) solution of
The preparation of B-OH and F-OH are essentially
identical to that of A-OH and E-OH [17]. From 4 (1.57
g, 25.7 mmol), tetraethylenegylcol ditosylate (13) (10.79
g, 21.5 mmol) [18] and Na2CO3 (10.16 g, 95.6 mmol) in
30 ml MeCN, B-OH (1.76 g, 37.3%) and F-OH (0.41 g,
4.3%) were obtained as pale yellow oil.

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
117
The solvent was removed and the residue was dissolved
in H2O, which was extracted with CH2Cl2. The organic
layer was dried over MgSO4, and the solvent was
removed under reduced pressure to give the faintly
yellow oil of C-OH (0.56 g, 2.13 mmol, 57.0%).
C-OH. 1H-NMR (CDCl3): l 2.67 (t, 2H, chain-
CH2N), 2.76 (t, 4H, ring-CH2N), 3.64 (m, 20H, CH2O).
13C-NMR (CDCl3): l 55.55 (ring-CH2N), 57.92 (chain-
CH2N), 59.39 (CH2OH), 69.99, 70.13, 70.53 and 70.77
(CH2O). IR (neat, NaCl, cm−1): w(OH) 3270. EIMS;
m/e (% relative intensity): 263 ([M+], 9.59)
(C12H25O5N, 263.33).
10 (3.81 g, 16.3 mmol) was added dropwise and the
mixture was stirred for 30 min. A THF (50 ml) solution
of 5 (7.44 g, 16.2 mmol) was added to the mixture
within 20 min. The resultant mixture was stirred further
for 75 h. The mixture was filtered, and the filtrate was
extracted with CHCl3 and dried over MgSO4. The
solvent was removed, and the residue was purified by
column chromatography (Al2O3, CHCl3) to give color-
less oil of N-(2-pyranyloxyethyl)-4-aza-15-crown-5 (11)
(2.44 g, 7.02 mmol, 43.4%).
1
11. H-NMR (CDCl3): l 1.55 (m, 6H, py-CH2), 2.80
(t, 2H, chain-CH2N), 2.84 (t, 4H, ring-CH2N), 3.6 (m,
20H, CH2O), 4.63 (m, CH, 1H). 13C-NMR (CDCl3): l
19.66, 25.56 and 30.78 (py-CH2), 55.16 (ring-CH2N),
56.01 (chain-CH2N), 62.31 (CH2O), 65.86 (CH2O),
70.13, 70.20, 70.45 and 71.02 (ring-CH2O), 98.96 (CH).
IR (neat, NaCl, cm−1): 2941, 2867.
1
The H-NMR data are in agreement with those given
in Ref. [11].
3.4. N-(2-Hydroxyethyl)-4-aza-18-crown-6 (D-OH)
A mixture of 11 (1.30 g, 3.74 mmol), MeOH (8 ml)
and aq. HCl (6 mol l−1, 2 ml) was stirred for 12 h
followed by the addition of Na2CO3 and stirred again.
The synthesis of D-OH is essentially identical to that
of C-OH except that tetraethyleneglycol ditosylate (13)
was used instead of 5. To a suspension of NaH (2.65 g,
Fig. 6. Assignment of 13C-NMR spectra of some azacrown ethers.

118
R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
Fig. 7. Assignment of 1H- and 13C-NMR spectra of K-OH and K.
3.5. N-{2-(2-Hydroxyethoxy)ethyl}-4-aza-9-crown-3
(G-OH) and N,N%-bis{2-(2-hydroxyethoxy)ethyl}-4,13-
diaza-18-crown-6 (K-OH)
110.4 mmol) in THF (350 ml), a THF (50 ml) solu-
tion of 10 (10.47 g, 44.9 mmol) was added dropwise
and stirred for 30 min. A THF solution (100 ml) of
13 (22.49 g, 4.47 mmol) was added dropwise to the
mixture within 20 min. The resulting mixture was
stirred further for 69 h. The mixture was filtered, and
the solvent was removed. The residue was dissolved
in H2O, extracted with CHCl3 and dried over MgSO4.
The solvent was removed, and the residue was
purified by column chromatography (Al2O3, CHCl3)
to give a colorless oil of N-(2-pyranyloxyethyl)-4-aza-
18-crown-6 (27) (8.49 g, 21.7 mmol, 45.8%).
The method used in the preparation of G-OH and
K-OH is identical to that for A-OH and E-OH except
that 2-(2-aminoethoxy)ethanol (12) was used instead of
4. Thus, from 12 (2.44 g, 23.2 mmol), 5 (9.04 g, 19.7
mmol) and Na2CO3 (9.08 g, 85.7 mmol), a pale yellow
oil of N-{2-(2-hydroxyethoxy)ethyl}-4-aza-9-crown-3
(G-OH) (0.46 g, 10.7%) and N,N%-bis{2-(2-hydrox-
yethoxy)ethyl}-4,13-diaza-18-crown-6 (K-OH) (0.46 g,
10.6%) were obtained.
27. 1H-NMR (CDCl3): l 1.55 (m, 6H, py-CH2),
2.80 (t, 2H, chain-NCH2) 2.84 (t, 4H, ring-NCH2)
3.70 (m, 24H, OCH2), 4.60 (m, CH, 1H). 13C-NMR
(CDCl3,): l 19.69, 25.57 and 30.79 (py-CH2), 54.67
(ring-CH2N), 55.04 (chain-CH2N), 62.34 and 65.79
(CH2O), 69.90, 70.39, 70.76, 70.86 and 98.97 (ring-
CH2O).
1
G-OH. H-NMR (CDCl3, 400 MHz): l 2.83 (t, 2H,
chain-NCH2), 2.92 (t, 4H, ring-NCH2), 3.70 (m, 10H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 54.85 (ring-
NCH2), 56.50 (chain-NCH2), 61.73 (CH2OH), 68.92,
72.00, 72.25 and 72.25 (OCH2). IR (neat, NaCl, cm−1):
w(OH) 3422. EIMS; m/z (% relative intensity): 219
([M+], 6.41) (C10H21O4N, 219.28).
The acid-catalyzed hydrolysis of 27 to D-OH was
carried out in a similar manner as that for C-OH.
Thus, from 27 (1.76 g, 4.50 mmol), yellow oil of
D-OH (0.39 g, 3.03 mmol, 67.2%) was obtained.
1
D-OH. H-NMR (CDCl3, 400 MHz): l 2.70 (t, 2H,
chain-CH2N), 2.79 (t, 4H, ring-CH2N), 3.64 (m, 24H,
CH2O). 13C-NMR (CDCl3, 100 MHz): l 54.92 (ring-
CH2N), 57.18 (chain-CH2N), 59.32 (CH2OH), 69.84,
70.34, 70.64 70.76 and 70.89 (CH2O). IR (neat, NaCl,
cm−1): 3219. EIMS; m/e (% relative intensity):
306([M+], 4.14) (C14H29O6N, 307.39).
1
The H-NMR data are in agreement with those in
Ref. [11].
Fig. 8. Cation transport experiment.

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
119
1
K-OH. H-NMR (CDCl3, 400 MHz): l 2.75 (t, 4H,
2-(2-hloroethoxy)ethylpyranyl ether (15) (24.45 g,
chain-NCH2), 2.84 (t, 8H, ring-NCH2), 3.62 (m, 30H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 54.39 (ring-
NCH2), 55.53 (chain-NCH2), 61.69 (CH2OH), 68.89,
69.39, 70.53 and 72.56 (OCH2). IR (neat, NaCl, cm−1):
3327. EIMS; m/e (% relative intensity): 438 ([M+], 4.87)
(C32H66O10N2, 438.56).
84.7%).
1
15. H-NMR (CDCl3): l 1.51–1.87 (m, 6H, py-CH2),
3.48–3.97 (m, 10H, CH2O), 4.63–4.65 (m, 1H, CH).
13C-NMR (CDCl3): l 19.61, 25.53 and 30.70 (py-CH2),
42.79 (CH2Cl), 62.30, 66.68, 70.66 and 71.37 (CH2O),
98.95(CH). IR (neat, NaCl, cm−1): 2943.
A mixture of 15 (12.52 g, 60.0 mmol), 9 (6.31 g, 60.0
mmol) and K2CO3 (10.77 g, 78.0 mmol) was stirred in
DMF (100 ml) for 42 h. The DMF was removed under
reduced pressure, and the solid was filtered. The filtrate
was dissolved in CH2Cl2, dried and evaporated. By
distillation in vacuo (180 °C, 3 Torr), a colorless oil of
N-{2-(2-pyranyloxyethoxy)ethyl}diethanolamine (16)
(8.42 g, 48.2%) was obtained.
3.6. N-{2-(2-Hydroxyethoxy)ethyl}-4-aza-12-crown-4
(H-OH) and N,N%-bis{2-(2-hydroxyethoxy)ethyl}-
7,19-diaza-24-crown-8 (L-OH)
The preparation of H-OH and L-OH was carried out
in a similar manner as described in Section 3.5 except
that 13 was employed instead of 5 as the ring source.
Thus, to a refluxing mixture of Na2CO3 (4.77 g, 45.4
mmol) in MeCN (250 ml), 12 (18.37 g, 173.3 mmol) was
added and the reflux was continued for 1 h, to which a
MeCN solution (80 ml) of 13 (20.07 g, 39.9 mmol) was
added dropwise. After refluxing for 24 h, the solid was
filtered, and the solvent was removed under reduced
pressure. Water was added and the mixture was ex-
tracted with CHCl3. The organic layer was dried and
removed under reduced pressure. The residue was chro-
matographed on alumina (CHCl3–2-propanol=10:1)
and separated by GPC to give a pale yellow oil of
1
16. H-NMR (CDCl3): l 1.55–1.83 (m, 6H, py-CH2),
2.69–2.73 (m, 6H, CH2N), 3.50–3.91 (m, 12H, CH2O),
4.15–4.58 (m, 1H, CH). 13C-NMR (CDCl3): l 19.95,
25.11 and 30.61 (py-CH2), 54.03 and 57.07 (CH2N),
59.45, 59.45, 63.10 and 66.29 (CH2O), 99.51(CH). IR
(neat, NaCl, cm−1): 3399.
To a suspension of NaH (1.21 g, 50.5 mmol) in THF
(200 ml), a THF (50 ml) solution of 16 (4.87 g, 17.6
mmol) was added dropwise and the mixture was stirred.
A THF (80 ml) solution of 5 (8.54 g, 18.6 mmol) was
added to the mixture within 20 min. The resultant
mixture was stirred further for 36 h at room tempera-
ture (r.t.). The mixture was filtered, and H2O was added
to the filtrate, which was extracted with CHCl3, and the
organic layer was dried over MgSO4. The solvent was
removed, and the residue was purified by column chro-
matography (Al2O3, CHCl3) to give a colorless oil of
N-{2-(2-pyranyloxyethoxy)ethyl}-4-aza-15-crown-5 (28)
(3.70 g, 9.68 mmol, 55.5%).
N-{2-(2-hydroxyethoxy)ethyl}-4-aza-12-crown-4
(H-
OH) (3.05 g, 25.5%) and N,N%-bis{2-(2-hydrox-
yethoxy)ethyl}-7,19-diaza-24-crown-8 (L-OH) (0.75 g,
5.14%).
1
H-OH. H-NMR (CDCl3, 400 MHz): l 2.71 (t, 2H,
chain-NCH2), 2.76 (t, 4H, ring-NCH2), 3.63 (m, 18H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 55.47 (ring-
NCH2), 56.36 (chain-NCH2), 61.04 (CH2OH), 69.23,
69.83, 70.20, 70.87 and 72.31 (OCH2). IR (neat, NaCl,
cm−1): 3309. EIMS; m/z (% relative intensity):
263([M+], 7.60) (C12H25O5N, 263.33).
1
28. H-NMR (CDCl3): l 1.55 (m, 6H, py-CH2), 2.80
(t, 2H, chain-NCH2), 2.84 (t, 4H, ring-NCH2), 3.6 (m,
20H, CH2O), 4.63 (m, CH, 1H). 13C-NMR (CDCl3): l
19.66, 25.56 and 30.78 (py-CH2), 55.16 (ring-NCH2),
56.01 (chain-NCH2), 62.31, 65.86, 70.13, 70.20, 70.45
and 71.02 (CH2O), 98.96 (CH).
1
L-OH. H-NMR (CDCl3, 400 MHz): l 2.79 (t, 4H,
chain-NCH2), 2.82 (t, 8H, ring-NCH2), 3.63 (m, 36H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 54.34 (ring-
NCH2), 55.28 (chain-NCH2), 61.62 (CH2OH), 69.02,
69.37, 70.38, 70.64 and 72.48 (OCH2). IR (neat, NaCl,
cm−1): 3384. EIMS; m/z (% relative intensity): 526
([M+], 5.71) (C24H50O10N2, 526.67).
A mixture of 28 (1.05 g, 2.68 mmol), MeOH (14 ml)
and aq. HCl (6 mol l−1, 2 ml) was stirred for 12 h.
Na2CO3 was added and stirred thoroughly. The solvent
was removed and the residue was dissolved in H2O, and
the mixture was extracted with CH2Cl2. The organic
layer was dried over MgSO4, and the solvent was
removed under reduced pressure to give a faintly yellow
oil of I-OH (0.40 g, 1.03 mmol, 48.6%).
3.7. N-{2-(2-Hydroxyethoxy)ethyl}-4-aza-15-crown-5
(I-OH)
A mixture of 2-(2-chloroethoxy)ethanol (14) (17.25 g,
138.4 mmol) and TsOH (0.01 g) was added dropwise to
7 (23.15 g, 275.2 mmol) at 0 °C and stirred continu-
ously for 12 h. Aq. NaHCO3 (10%, 100 ml) was added
and the mixture was extracted with CH2Cl2. The or-
ganic layer was dried over MgSO4 and the solvent was
removed under reduced pressure. The residue was dis-
tilled in vacuo (80 °C, 8 Torr) to give a colorless oil of
1
I-OH. H-NMR (CDCl3, 400 MHz): l 2.78 (t, 2H,
chain-NCH2), 2.84 (t, 4H, ring-NCH2), 3.63 (m, 23H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 54.93 (ring-
NCH2), 56.31 (chain-NCH2), 61.66 (CH2OH), 68.96,
69.40, 70.01, 70.23, 70.82 and 72.43 (OCH2). IR (neat,
NaCl, cm−1): 3258. EIMS; m/z (% relative intensity):
306 ([M+], 10.0) (C14H29O6N, 307.38).

120
R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
The alcohols I-OH and J-OH were prepared by the
mmol) in CHCl3 (10 ml) was cooled to 0 °C, and DCC
(0.34 g, 1.65 mmol) was added. The resulting mixture
was stirred for 24 h, filtered and concentrated under
reduced pressure. The residue was purified by column
chromatography on silica gel using benzene–ethyl ace-
tate (1:1) as the eluent. The yield was 0.29 g (0.83
mmol, 63.6%).
reaction of the corresponding azacrowns with 2-
chloroethanol. Neither the yield nor the spectroscopic
data are described in the literature [19].
3.8. N-{2-(2-Hydroxyethoxy)ethyl}-4-aza-18-crown-6
(J-OH)
A. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 0.99 (m, 2H, GeCH2), 2.35 (m, 2H,
GeCH2CH2), 2.88 (m, 6H, NCH2), 3.74 (m, 8H,
OCH2), 4.16 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.50 (Me3Ge), 11.53 (GeCH2), 29.96
(GeCH2CH2), 55.73 (chain-CH2N), 55.84 (ring-CH2N),
62.50 (OCOCH2), 72.24 and 72.41 (CH2O), 174.81
(CꢁO). IR (neat, NaCl, cm−1): 1736. DE MALDI-
TOFMS; m/z: 346.08, 348.08, 349.08, 350.07, 351.08,
352.07 (C14H29O4NGe, 348.00).
To a suspension of NaH (2.65 g, 110.4 mmol) in
THF (350 ml), a THF (50 ml) solution of 16 (10.47 g,
44.9 mmol) was added dropwise and the mixture was
stirred for 30 min following with an addition of a THF
(80 ml) solution of 13 (22.49 g, 44.7 mmol) to the
mixture. The resultant mixture was stirred further for
69 h at r.t. The mixture was filtered, and H2O was
added to the filtrate, which was extracted with CHCl3,
and the organic layer was dried over MgSO4. The
solvent was removed, and the residue was purified by
column chromatography (Al2O3, CHCl3) to give a col-
orless oil of N-{2-(2-pyranyloxyethoxy)ethyl}-4-aza-18-
crown-6 (17) (5.78 g, 16.16 mmol, 45.8%).
3.10. 3-Trimethylgermylpropionate of
N-(2-hydroxyethyl)-4-aza-12-crown-4 (B)
17. 1H-NMR (CDCl3, 400 MHz): l 1.55 (m, 6H,
CH2), 2.80 (t, 2H, chain-NCH2), 2.84 (t, 4H, ring-
NCH2), 3.70 (m, 24H, OCH2), 4.60 (m, 1H, OCHO).
13C-NMR (CDCl3, 100 MHz): l 19.69, 25.57 and 30.79
(py-CH2), 54.67 (ring-CH2N), 55.04 (chain-CH2N),
62.34 (CH2OH), 65.79, 69.90, 70.39, 70.76, 70.86 and
70.86 (OCH2), 98.97 (OCHO).
B was prepared under the similar conditions men-
tioned above from B-OH (0.24 g, 1.09 mmol), 18 (0.32
g, 1.68 mmol), 29 (0.21 g, 1.72 mmol) and DCC (0.34 g,
1.65 mmol) as a pale yellow oil (0.34 g, 0.87 mmol,
79.6%). The eluent used for chromatography was ben-
zene–ethyl acetate=1:1.
B. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 0.99 (m, 2H, GeCH2), 2.33 (m, 2H,
GeCH2CH2), 2.81 (t, 6H, CH2N), 3.65 (m, 12H,
CH2O), 4.17 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): −2.51(Me3Ge), 11.50 (GeCH2), 29.93
(GeCH2CH2), 54.76 (chain-CH2N), 55.36 (ring-CH2N),
62.25 (OCOCH2), 70.23, 70.31 and 71.06 (CH2O),
174.74 (CꢁO). IR (neat, NaCl, cm−1): 1736. DE
MALDI-TOFMS; m/z: 390.09, 391.09, 392.09, 393.09,
394.08, 395.09, 396.09 (C16H33O5NGe, 392.05).
A mixture of 17 (1.03 g, 2.36 mmol), MeOH (10 ml)
and aq. HCl (6 mol, 3 dm−3) was stirred for 12 h.
Na2CO3 was added and stirred further. The solvent was
removed and the residue was dissolved in H2O, and the
mixture was extracted with CH2Cl2. The organic layer
was dried over MgSO4, and the solvent was removed
under reduced pressure to give a faintly yellow oil of
J-OH (0.45 g, 1.28 mmol, 54.3%).
1
J-OH. H-NMR (CDCl3, 400 MHz): l 2.75 (t, 2H,
chain-NCH2), 2.83 (t, 4H, ring-NCH2), 3.63 (m, 26H,
OCH2). 13C-NMR (CDCl3, 100 MHz): l 54.52 (ring-
NCH2), 55.85 (chain-NCH2), 61.83 (CH2OH), 69.07,
69.49, 70.29, 70.67, 70.81 and 72.57 (OCH2). IR (neat,
NaCl, cm−1): 3283. EIMS; m/z (% relative intensity):
350 ([M+], 5.50) (C16H33O7N, 351.44).
3.11. 3-Trimethylgermylpropionate of
N-(2-hydroxyethyl)-4-aza-15-crown-5 (C)
C was prepared from C-OH (0.27 g, 1.03 mmol), 18
(0.32 g, 1.68 mmol), 29 (0.17 g, 1.39 mmol) and DCC
(0.32 g, 1.55 mmol) and 29 (0.17 g, 1.39 mmol) as a
pale yellow oil (0.17 g, 1.39 mmol, 72.8%). The eluent
used was CHCl3–MeOH=10:1.
3.9. 3-Trimethylgermylpropionate of
N-(2-hydroxyethyl)-4-aza-9-crown-3 (A)
C. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 0.99 (m, 2H, GeCH2), 2.33 (m, 2H,
GeCH2CH2), 2.81 (m, 6H, CH2N), 3.66 (m, 16H,
CH2O), 4.14 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.38 (Me3Ge), 11.65 (GeCH2), 30.04
(GeCH2CH2), 54.79 (chain-CH2N), 55.01 (ring-CH2N),
62.55 (OCOCH2), 70.10, 70.20, 70.44 and 71.00
(CH2O), 174.77 (CꢁO). IR (neat, NaCl, cm−1): 1735.
DE MALDI-TOFMS; m/z: 434.06, 435.07, 436.06,
437.06, 438.06, 439.06, 440.06 (C18H37O6NGe, 436.10).
3-Trimethylgermylpropionic acid (18) was prepared
by the Grignard reaction of 3-trichlorogermyl propionic
acid with methyl magnesium iodide. The germylpropi-
onic acid was obtained by the hydrogermylation of
acrylic acid with trichlorogermane [20].
Germylation of A-OH–J-OH with 18 can generally
be achieved with the aid of DCC and 4-dimethy-
laminopyridine (29). Thus, a solution of A-OH (0.23 g,
1.31 mmol), 18 (0.36 g, 1.89 mmol) and 29 (0.23 g, 1.88

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
121
3.12. 3-Trimethylgermylpropionate of
3.15. 3-Trimethylgermylpropionate of
N-(2-hydroxyethyl)-4-aza-18-crown-6 (D)
N-{2-(2-hydroxyethoxy)ethyl}-4-aza-9-crown-3 (G)
D was prepared from D-OH (0.57 g, 1.85 mmol), 18
(0.66 g, 3.46 mmol), DCC (0.27 g, 2.20 mmol) and 29
(0.60 g, 2.90 mmol) as a pale yellow oil (0.41 g; 0.94
mmol, 56.8%). The eluent used was CHCl3–MeOH=
8:1.
G was prepared (from G-OH (0.26 g, 1.19 mmol), 18
(0.33 g, 1.73 mmol), 29 (0.18 g, 1.47 mmol) and DCC
(0.34 g, 1.65 mmol) as a pale yellow oil (0.33 g, 0.84
mmol, 70.7%). The eluent used was CHCl3–MeOH=
8:1.
D. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 0.99 (m, 2H, GeCH2), 2.34 (m, 2H,
GeCH2CH2), 2.83 (m, 6H, CH2N), 3.65 (m, 20H,
CH2O), 4.15 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.51 (Me3Ge), 11.51 (GeCH2), 29.92
(GeCH2CH2), 53.77 (chain-CH2N), 54.42 (ring-CH2N),
62.47 (OCOCH2), 69.84, 70.29, 70.63 and 70.76
(CH2O), 174.76 (CꢁO). IR (neat, NaCl, cm(1): 1734.
DE MALDI-TOFMS; m/z: 478.08, 479.07, 480.08,
481.07, 482.07, 483.07, 484.07, 485.08 (C20H41O7NGe,
480.16).
G. 1H-NMR (CDCl3, 400 MHz): l 0.14 (s, 9H,
Me3Ge), 1.00 (m, 2H, GeCH2), 2.37 (m, 2H,
GeCH2CH2), 2.88 (m, 6H, CH2N), ca. 3.6 (m, 12H,
CH2O), 4.22 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.50 (Me3Ge), 11.50 (GeCH2), 29.87
(GeCH2CH2), 55.96 (ring-CH2N), 56.74 (chain-CH2N),
63.46 (OCOCH2), 68.90, 70.03, 72.26 and 72.54
(CH2O), 174.83 (CꢁO). IR (neat, NaCl, cm−1): 1736.
DE MALDI-TOFMS; m/z: 390.07, 391.07, 392.06,
393.06, 394.06, 395.06, 396.06, 397.05 (C16H33O5NGe,
392.05).
3.13. 3-Trimethylgermylpropionate of
3.16. 3-Trimethylgermylpropionate of
N,N(-bis((2-hydroxyethyl))-4,13-diaza-18-crown-6 (E)
N-{2-(2-hydroxyethoxy)ethyl}-4-aza-12-crown-4 (H)
E was obtained from E-OH (0.37 g, 1.06 mmol), 18
(0.51 g, 2.67 mmol) and 29 (0.26 g, 2.10 mmol), DCC
(0.48 g, 2.33 mmol) as a pale yellow oil (0.31 g, 0.46
mmol, 43.5 %%). The eluent used was CHCl3–
MeOH=4:1. E. 1H-NMR (CDCl3, 400 MHz): (0.13 (s,
18H, Me3Ge), 0.99 (m, 4H, GeCH2), 2.34 (m, 4H,
GeCH2CH2), 2.90 (t, 12H, CH2N), 3.62 (m, 16H,
CH2O), 4.17 (t, 4H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): (2.50 (Me3Ge), 11.50 (GeCH2), 29.91
(GeCH2CH2), 53.43 (chain-CH2N), 54.34 (ring-CH2N),
62.12 (OCOCH2), 69.51 and 70.55 (CH2O), 174.74
(C(O). IR (neat, NaCl, cm(1): 1735. DE MALDI-
TOFMS; m/z: 690.99, 692.99, 694.99, 696.99, 697.99,
698.98, 699.99, 700.98, 701.98 (C28H58O8N2Ge2,
696.00).
H was prepared from H-OH (0.25 g, 0.95 mmol), 18
(0.27 g, 1.42 mmol), 29 (0.17 g, 1.39 mmol) and DCC
(0.28 g, 1.36 mmol) as a pale yellow oil (0.17 g, 0.39
mmol, 41.0%). The eluent used was CHCl3–MeOH=
10:1.
H. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 1.00 (m, 2H, GeCH2), 2.36 (m, 2H,
GeCH2CH2), 2.78 (t, 6H, CH2N), 3.65 (m, 16H,
CH2O), 4.21 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.50 (Me3Ge), 11.49 (GeCH2), 29.85
(GeCH2CH2), 55.53 (ring-CH2N), 56.01 (chain-CH2N),
63.48 (OCOCH2), 68.93, 69.56, 70.17, 70.25 and 70.96
(CH2O), 174.85 (CꢁO). IR (neat, NaCl, cm−1): 1735.
DE MALDI-TOFMS; m/z: 434.12, 435.12, 436.12,
437.12, 438.11, 439.12, 440.11 (C18H37O6NGe, 436.10).
3.14. 3-Trimethylgermylpropionate of
3.17. 3-Trimethylgermylpropionate of
N,N%-bis(2-hydroxyethyl)-7,19-diaza-24-crown-8 (F)
N-{2-(2-hydroxyethoxy)ethyl}-4-aza-15-crown-5 (I)
F was prepared from F-OH (0.22 g, 0.50 mmol), 18
(0.27 g, 1.42 mmol), 29 (0.17 g, 1.39 mmol) and DCC
(0.29 g, 1.41 mmol) as a pale yellow oil (0.31 g, 0.46
mmol, 87.5%). The eluent used was CHCl3–MeOH=
8:1.
I was prepared from I-OH (0.13 g, 0.42 mmol), 18
(0.14 g, 0.73 mmol), 29 (0.08 g, 0.66 mmol) and DCC
(0.15 g, 0.73 mmol) as a pale yellow oil (0.10 g, 0.42
mmol, 49.2%). The eluent used was CHCl3–MeOH=
3:1.
F. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 18H,
Me3Ge), 0.99 (m, 4H, GeCH2), 2.34 (m, 4H,
GeCH2CH2), 2.85 (t, 12H, CH2N), 3.62 (m, 24H,
CH2O), 4.15 (t, 4H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.50 (Me3Ge), 11.52 (GeCH2), 29.93
(GeCH2CH2), 53.59 (chain-CH2N), 54.44 (ring-CH2N),
62.48 (OCOCH2), 69.84, 70.50 and 70.72 (CH2O),
174.76 (CꢁO). IR (neat, NaCl, cm−1): 1736. DE
MALDI-TOFMS; m/z: 781.05, 783.06, 784.07, 785.06,
787.05, 789.05 (C32H66O10N2Ge2, 784.10).
I. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 9H,
Me3Ge), 0.99 (m, 2H, GeCH2), 2.37 (m, 2H,
GeCH2CH2), 2.88 (t, 6H, CH2N), 3.66 (m, 20H,
CH2O), 4.23 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.53 (Me3Ge), 11.40 (GeCH2), 29.77
(GeCH2CH2), 54.85 (CH2N), 62.23 (OCOCH2), 67.73,
69.03, 69.84, 70.06 and 70.37 (CH2O), 174.78 (CꢁO). IR
(neat, NaCl, cm−1): 1735. DE MALDI-TOFMS; m/z:
478.11, 479.11, 480.11, 481.11, 482.11, 483.11, 484.11
(C20H41O7NGe, 480.16).

122
R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
3.18. 3-Trimethylgermylpropionate of
N-{2-(2-hydroxyethoxy)ethyl}-4-aza-18-crown-6 (J)
DE MALDI-TOFMS; m/z: 867.06, 869.06, 871.06,
872.06, 873.05, 875.07, 876.06, 877.05 (C36H74O12N2Ge,
872.20).
J was prepared from J-OH (0.13 g, 0.37 mmol), 18
(0.15 g, 0.79 mmol), 29 (0.08 g, 0.66 mmol) and DCC
(0.15 g, 0.73 mmol) as a pale yellow oil (0.06 g, 0.11
mmol, 30.8%). The eluent used was CHCl3–MeOH=
3:1.
3.21. Attempted germylation of C-OH with
3-(trimethylgermyl) propionyl chloride
A solution of C-OH (0.46 g, 1.75 mmol) in CHCl3
(12 ml) was refluxed, to which a solution of 20 (0.53 g,
2.53 mmol) in CHCl3 (10 ml) was added dropwise.
Heating was continued for 24 h. The solvent was
removed under reduced pressure and the residue was
purified by GPC to give a pale yellow liquid of
C.hydrochloride (0.71 g, 1.50 mmol, 85.9%).
J. 1H-NMR (CDCl3, 400 MHz): l 0.14 (s, 9H,
Me3Ge), 1.00 (m, 2H, GeCH2), 2.38 (m, 2H,
GeCH2CH2), 2.88 (m, 6H, CH2N), 3.65 (m, 24H,
CH2O), 4.22 (t, 2H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.48 (Me3Ge), 11.50 (GeCH2), 29.87
(GeCH2CH2), 54.58 (CH2N), 63.47 (OCOCH2), 68.95,
69.20, 70.21, 70.59 and 70.70 (CH2O), 174.85 (CꢁO). IR
(neat, NaCl, cm−1): 1734. DE MALDI-TOFMS; m/z:
522.14, 523.14, 524.16, 525.16, 526.15, 527.14, 528.15
(C22H45O8NGe, 526.23).
1
C.hydrochloride. H-NMR (CDCl3, 400 MHz): l 0.14
(b, 9H, CH3Ge), 1.00 (b, 2H, CH2Ge), 2.38 (b, 2H,
CH2CH2Ge), 3.16 (b, 6H, NCH2), 3.68 (b, 16H,
OCH2), 4.23 (b, 2H, COOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.55 (CH3Ge), 11.40 (GeCH2), 29.77
(CH2CH2Ge), 54.85 (CH2N), 63.23 (COOCH2), 67.73,
69.83, 70.06 and 70.31 (CH2O), 174.77 (CO).
Neutralization of C.hydrochloride with Na2CO3 gave
C after purification (Yield: 28% ). The spectroscopic
data of C thus obtained are essentially identical with
those of C obtained with the method described in
Section 3.11.
3.19. 3-Trimethylgermylpropionate of
N,N%-bis{2-(2-hydroxyethoxy)ethyl}-
4,13-diaza-18-crown-6 (K)
K was prepared from 10 (0.21 g, 0.48 mmol), 18 (0.26
g, 1.36 mmol), 29 (0.17 g, 1.39 mmol) and DCC (0.28 g,
1.36 mmol) as a pale yellow oil (0.18 g, 0.25 mmol,
51.6%). The eluent used was CHCl3–MeOH=6:1.
K. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 18H,
Me3Ge), 1.00 (m, 4H, GeCH2), 2.37 (m, 4H,
GeCH2CH2), 2.77 (t, 4H, chain-CH2N), 2.84 (t, 8H,
ring-CH2N), 3.61 (m, 24H, CH2O), 4.17 (t, 4H,
OCOCH2). 13C-NMR (CDCl3, 100 MHz): l −2.45
(Me3Ge), 11.53 (GeCH2), 29.90 (GeCH2CH2), 54.47
(ring-CH2N), 54.82 (chain-CH2N), 63.52 (OCOCH2),
68.97, 69.69, 69.89 and 70.68 (CH2O), 174.88 (CꢁO). IR
(neat, NaCl, cm−1): 1735. DE MALDI-TOFMS; m/z:
779.15, 781.15, 782.15, 783.15, 785.16, 787.15, 788.16,
789.14 (C32H66O10N2Ge2, 784.10).
3.22. Attempted hydrogermylation of an allylazacrown
ether
To a solution of 9 (22.1 g, 210 mmol) and Na2CO3
(1.20 g, 106 mmol) in MeCN (250 ml), a solution of
allyl bromide (21) (30.3 g, 250 mmol) was added drop-
wise, and the reaction mixture was stirred for 24 h.
After cooling, CH2Cl2 (50 ml) was added and the solid
was filtered. The organic layer was dried and removed
under reduced pressure. The residue was distilled in
vacuo (150 °C, 7 Torr) to give a colorless oil of N-al-
lyldiethanolamine (22) (17.9 g, 58.6%).
1
3.20. 3-Trimethylgermylpropionate of
N,N%-bis{2-(2-hydroxyethoxy)ethyl}-7,19-
diaza-24-crown-8 (L)
22. H-NMR (CDCl3, 400 MHz): l 2.61–2.68 (m,
4H, NCH2), 3.19–3.21 (m, 2H, CH2ꢁCHꢀCH2), 3.60–
3.62 (m, 4H, ꢀCH2O), 4.07 (s, 2H, OH), 5.15–5.26 (m,
2H,
CH2ꢁCHꢀCH2),
5.81–5.91
(m,
1H,
L was prepared (19.5%) from L-OH (0.28 g, 0.53
mmol), 18 (0.33 g, 1.73 mmol), 29 (0.19 g, 1.56 mmol)
and DCC (0.35 g, 1.70 mmol) as a pale yellow oil (0.09
g, 0.10 mmol, 19.5%). The eluent used was CHCl3–
MeOH=10:1.
CH2ꢁCHꢀCH2). 13CꢀNMR (CDCl3, 100 MHz): l 55.70
(NCH2), 57.61 (CH2ꢁCHꢀCH2), 59.45 (CH2O), 118.03
(CH2ꢁCHꢀCH2), 134.86 (CH2ꢁCHꢀCH2). IR (neat,
NaCl, cm−1): w(CꢀN) 1446, 1419, 1361, 1041.
Sodium hydride (3.09 g, 128 mmol) in THF (120 ml)
was refluxed, to which a solution of 22 (3.61 g, 24,8
mmol) in THF (50 ml) was added dropwise. Refluxing
was continued for 20 h. Water was added, and THF
was removed under reduced pressure. The residue was
extracted with CHCl3. The solvent was removed, and
the residue was purified by column chromatography
(Al2O3, CHCl3) and GPC to give N-allyl-4-aza-15-
crown-5 (23) as a yellow oil (2.70 g, 42%).
L. 1H-NMR (CDCl3, 400 MHz): l 0.13 (s, 18H,
Me3Ge), 1.00 (m, 4H, GeCH2), 2.37 (m, 4H,
GeCH2CH2), 2.81 (m, 12H, CH2N), 3.62 (m, 36H,
CH2O), 4.20 (t, 4H, OCOCH2). 13C-NMR (CDCl3, 100
MHz): l −2.45 (Me3Ge), 11.53 (GeCH2), 29.89
(GeCH2CH2), 54.56 (ring-CH2N), 54.73 (chain-CH2N),
63.52 (OCOCH2), 68.95, 69.66, 69.84, 70.52 and 70.76
(CH2O), 174.88 (CꢁO). IR (neat, NaCl, cm−1): 1736.

R. Suzuki et al. / Journal of Organometallic Chemistry 636 (2001) 108–123
123
23. 1H-NMR (CDCl3, 400 MHz): l 2.72 (m, 4H
Acknowledgements
NCH2), 3.16–3.17 (m, 2H, CH2ꢁCHꢀCH2), 3.62–3.76
(m, 16H, OCH2), 5.05–5.13 (m, 2H, CH2ꢁCHꢀCH2),
5.82–5.92 (m, 1H, CH2ꢁCHꢀCH2). 13C-NMR (CDCl3,
100 MHz): l 54.16 (NCH2), 59.99 (CH2ꢁCHꢀCH2),
69.88, 70.15, 70.41 and 70.99 (OCH2) 117.46
(CH2ꢁCHꢀCH2) 135.81 (CH2ꢁCHꢀCH2). IR (neat,
NaCl, cm−1): w(CꢀN) 1431, 1041.
We thank the Ministry of Education, Culture,
Sports, Science and Technology for a Grand-in-Aid
for Scientific Research (11640547).
References
A
mixture of 23 (0.50 g, 1.54 mmol) and
triphenylgermane (24) (3.32 g, 1.23 mmol) was heated
with continuous stirring in the presence of a catalytic
amount of H2PtCl6·2H2O at 111 °C for 48 h. The
solid was filtered, and the residue was dissolved in
CHCl3 (20 ml). The organic layer was dried over
MgSO4, and the solvent was removed under reduced
pressure. The residue was purified with GPC to give
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1
25. H-NMR (CDCl3, 400 MHz): l 1.46–1.51 (m,
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2.71(m, 4H, NCH2CH2O), 3.56–3.68 (m, 16H,
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Cation transport experiments were carried out by
the H-tube test (Fig. 8). Thus, in the bottom of the
H-tube, a CHCl3 solution of azacrown ether A–L (1
mmol dm−3; 7 ml) was added and in the right arm of
the H-tube (source phase), an aqueous salt solution
(100 mmol dm−3; 3 ml) was added. In the left arm of
the H-tube (receiving phase) pure H2O was taken. A
small magnetic bar was placed in the bottom of each
arm and stirred continuously. The whole tube was
kept at 25 °C for 24 h. The amount of cations in the
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