Organometallics
Article
m/z calcd 317.1723 [M + Na]+, found 317.1721. Anal. Calcd for
C17H26O4: C, 69.36; H, 8.90, Found: C, 69.11; H, 8.92.
developed novel synthesis routes to hydrazide adamantane
derivatives, namely, 2,2′-(adamantane-1,3-diyl)diacetic acid
dihydrazide, 2,2′-(diamantane-4,9-diyl)diacetic acid dihydrazide,
and 2,2′,2″-(adamantane-1,3,5-triyl)triacetic acid trihydrazide.
All of them were successfully linked to the organic ligand sphere
of Sn/S clusters, which was confirmed by means of mass spec-
trometry and/or X-ray diffraction and 119Sn, 1H, and 13C NMR
spectroscopy. We present novel organo-functionalized Sn/S
complexes [(R2Sn)4Sn2S10] (2), [(R2Sn)3S4]+ ([3]+),
[(R4Sn)4Sn2S10] (5), [(R4Sn)3S4]+ ([6]+), [(R5Sn2)2(μ-S)6]+
([7+H]+), [(R6Sn2)2(μ-S)6]+ ([8]+), [(R7Sn)4Sn2S10] (9),
[(R8Sn2)3S8]2+ ([10]2+), and [R9Sn3S4]+ ([11]+) (R2 = CMe2-
CH2C(Me)NNCMeAd, R4 = CMe2CH2CMeNNHCOAd,
R5 = (CMe2CH2CMeNNHCO)2-1,3-Ad, R6 = (CMe2-
CH2CMeNNHCO)-1,3-Ad-(CH2CONHNCMeCH2CMe2),
Synthesis of Diethyl 2,2′-(Adamantane-1,3-diyl)diacetate (v′) (ref
23). NMR (ppm, CDCl3): 1H, 4.1 (q, 4H, J = 7.14, COOCH2Me), 2.1
(s, 4H, CH2COOEt), 2.0−2.1 (m, 2H, Ad), 1.4−1.6 (m, 12H, Ad), 1.2
(t, 6H, J = 7.13 COOCH2Me); 13C, 171.8 (CO), 60.1 (CH2), 48.7
(CH2), 47.5 (CH2), 41.7 (CH2), 36.0 (CH), 33.6 (CH), 29.1 (CH2),
14.6 (CH3). IR (cm−1): 2980 (w), 2901 (m), 2849 (w), 1728 (s), 1447
(m), 1370 (m), 1324 (m), 1248 (m), 1178 (w), 1134 (s), 1031 (s), 732
(s). HRMS: m/z calcd 331.1880 [M + Na]+, found 331.1880. Anal.
Calcd for C18H28O4: C, 70.10; H, 9.15, Found: C, 70.12; H, 9.06.
Synthesis of Dimethyl 2,2′-(Diamantan-4,9-diyl)diacetate (vi′). vi′
was prepared and analyzed according to reported methods.24
Synthesis of 1,3,5-Tri(bromomethyl)adamantane (vii″′). A sol-
ution of 2,2′,2″-(adamantane-1,3,5-triyl)triacetic acid trimethyl ester19
(5.24 g, 16.87 mmol) in Et2O (100 mL) was added dropwise to a
suspension of well-triturated LiAlH4 (3.85 g, 101.23 mmol) in dry Et2O
(400 mL). The resulting mixture was refluxed overnight. The reaction
mixture was cooled to 0 °C (ice bath), and consecutively water (4 mL),
10% aqueous NaOH (4 mL), and again water (12 mL) were added
dropwise, followed by stirring of the reaction mixture at rt for 30 min.
A colorless solid obtained by evaporation of the colorless suspension
in vacuo was flooded with aqueous HBr (48%, 250 mL), and the resulting
mixture was refluxed (165 °C in an oil bath) for 24 h. The mixture was
cooled to room temperature and diluted with water (250 mL), and the
crude product was extracted with CHCl3 (3 × 50 mL). The combined
extracts were washed with water and brine and were dried over Na2SO4.
Solvent removal yielded 5.1 g of crude product, which was purified
on a silica gel column (2% Et2O in pentane), providing pure 1,3,5-
tri(bromomethyl)adamantane (vii″′) (3.96 g, 57%). Colorless solid.
R7 = (CMe2CH2CMeNNHCOCH2)2-1,3-Ad, R8
=
=
(CMe2 CH2 CMeNNHCOCH2 )2 -4, 9-Diam, R9
(CMe2CH2CMeNNHCOCH2)3-1,3,5-Ad), which either were
received as single crystals (neutral compounds) or detected by
means of electrospray ionization mass spectrometry (cations).
First insights were gained into the impact of sterically demanding
diamondoid ligands on the composition and shape of organo-
functionalized Sn/S clusters.
EXPERIMENTAL SECTION
■
Syntheses. General Procedures. All manipulations were performed
under an argon atmosphere, unless otherwise noted. All solvents were
dried and freshly distilled prior to use. The syntheses of the known
ligand reactants i21a and ii21b and the precursors v′23,31 and vi′24,31 were
carried out according or similar to literature procedures. Compounds
iii,22 v (CAS 329699-84-5), and iv′ (CAS 201480-27-5) have been
mentioned in a patent or are commercially available, however, without
provision of synthesis details. Compounds iv, vi, and vii, as well as the
precursor vii′ and further precursors to vii′ (see below), are new
compounds. 1-Adamantylmethyl ketone (>98.0%) and 1-adamantane-
carboxylic acid ethyl ester (>98.0%) were purchased from TCI;
3-(carboxymethyl)adamantane-1-carboxylic acid (97%), dimethyl
adamantane-1,3-dicarboxylate (98%) (iii′), and 2,2′-(adamantane-1,3-
diyl)diacetic acid (97%) were purchased from Sigma-Aldrich; sulfuric
acid (95−97%) was purchased from Fluka; N2H4·H2O (80% in water)
was purchased from Merck and used as received. Silica gel 60 from
Macherey-Nagel was used with 0.063−0.2 mm/70−230 mesh ASTM.
NMR signals have been assigned with the help of NMR APT and COSY
measurements.
1
Mp = 91−93 °C (methanol). NMR (ppm, CDCl3): H, 3.2 (s, 6H,
CCH2Br), 2.2 (sep, 1H, CH), 1.4−1.5 (m, 6H, CCH2CH), 1.3 (s, 6H,
CCH2C); 13C, 46.27 (CH2), 43.28 (CH2), 39.38 (CH2), 35.44 (C),
28.97 (CH). MS: m/z (%) = 53 (8), 79 (13), 91 (21), 105 (23), 117 (7),
159 (8), 185 (10), 239/241 (9), 319/323 (51), 321 (100), 333/337 (5),
335 (10), 414/416 (0.5). IR (KBr, cm−1): 2938 (s), 2904 (s), 2844 (s),
1427 (m), 1343 (m), 1253 (s), 1154 (m), 1100 (m), 976 (m), 880 (m),
829 (m), 694 (m), 642 (m), 621 (s), 566 (m). HRMS: m/z calcd for
C13H19Br3 411.9037, found 411.8998. Anal. Calcd for C13H19Br3: C,
37.62; H, 4.61. Found: C, 37.81; H, 4.63.
Synthesis of 2,2′,2″-(Adamantane-1,3,5-triyl)triacetonitrile (vii″).
Tribromide vii″′ (3.00 g, 7.23 mmol) and n-Bu4NF·3H2O (11.40 g,
36.15 mmol) were dissolved in CH3CN (235 mL). Upon addition of
TMSCN (3.59 g, 4.52 mL, 36.15 mmol), the reaction mixture was
refluxed for 6 d. Upon cooling to room temperature, the reaction
mixture was diluted with water (235 mL) and the crude product was
extracted with CHCl3 (4 × 60 mL). The combined organic extracts were
washed with water and brine and were dried over Na2SO4. Solvent
removal provided a considerable amount of dark residue, which was
loaded on a silica gel column. Traces of unreacted starting material along
with other impurities were washed with pentane; changing the eluent to
Et2O produced pure 2,2′,2″-(adamantane-1,3,5-triyl)triacetonitrile vii″
(1.68 g, 92%). Colorless solid. Mp = 159−161 °C (benzene). NMR
(ppm, CDCl3): 1H, 2.3 (sep, 1H, CH), 2.2 (s, 6H, CCH2CN), 1.5−1.6
(m, 6H, CCH2CH), 1.5 (ABq, J = 23.9 Hz, 12.0 Hz, 6H, CCH2C); 13C,
116.89 (CN), 44.76 (CH2), 39.50 (CH2), 33.71 (C), 31.07 (CH2), 28.46
(CH). MS: m/z (%) = 91 (6), 105 (4), 117 (3), 130 (10), 145 (2), 157
(4), 172 (11), 186 (4), 213 (100), 253 (0.23). IR (KBr, cm−1): 3425 (b),
2925 (s), 2855 (s), 2245 (s), 1449 (s), 1422 (s), 1367 (m), 1356 (m).
HRMS: m/z calcd for C16H19N3 253.1579, found 253.1576. Anal. Calcd
for C16H19N3: C, 75.85; H, 7.56; N, 16.59. Found: C, 75.71; H, 7.64; N,
16.75.
Synthesis of 1-Adamantylmethyl Ketone Hydrazone (i). i was
prepared and analyzed according to reported methods.21a
Synthesis of 1-Adamantane Carbohydrazide (ii). ii was prepared
and analyzed according to reported methods.21b
General Procedure for the Synthesis of Adamantyl Diesters iv′ and
v′. On the basis of reported procedures31 dicarboxylic acid (12.0 mmol)
was dissolved in 50 mL of ethanol, concentrated H2SO4 (95−97%,
1 mL) was added, and the mixture was refluxed for 5 h. After cooling, the
solution was reduced to 50 mL and diluted with ethylacetate (100 mL).
The solution was washed two times with saturated aqueous NaHCO3
solution (2 × 50 mL), dried over Na2SO4, and filtered through a pad of
Celite, and the filtrate was concentrated in vacuo. All products were
obtained in quantitative yield as pure colorless oils and were used
without further purification.
Synthesis of Ethyl 2-(1-Ethoxycarbonyladamantane-3-yl)acetate
(iv′). NMR (ppm, CDCl3): 1H, 4.0−4.1 (m, 4H, COOCH2Me), 2.1 (s,
2H, CH2COOEt), 2.0−2.1 (m, 2H, Ad), 1.5−1.9 (m, 12H, Ad), 1.2−1.3
(m, 6H, COOCH2Me); 13C, 177.4 (CO), 171.6 (CO), 60.4 (CH2),
60.2 (CH2), 48.6 (CH2), 43.7 (CH2), 41.6 (CH), 41.5 (CH2), 38.3
(CH2), 35.9 (CH), 33.2 (CH), 28.6 (CH2), 14.6 (CH3), 14.4 (CH3). IR
(cm−1): 2979 (w), 2907 (m), 2855 (w), 1724 (s), 1450 (m), 1372 (w),
1330 (w), 1232 (s), 1164 (w), 1133 (s), 1104 (w), 1037 (s). HRMS:
Synthesis of Trimethyl 2,2′,2″-(Adamantane-1,3,5-triyl)triacetate
(vii′). Trinitrile vii″ (1.30 g, 5.12 mmol) and KOH (9.48 g, 169.06
mmol) were suspended in diethyleneglycol (40 mL), and the resulting
mixture was stirred (170 °C in an oil bath) for 24 h. Upon cooling to
room temperature, the reaction mixture was diluted with water (to
400 mL), nonacidic products were extracted with CHCl3 (3 × 30 mL),
the aqueous layer was acidified to pH = 1 (conc HCl) and saturated with
NaCl, and the crude triacid was extracted with EtOAc (7 × 100 mL).
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dx.doi.org/10.1021/om500014z | Organometallics 2014, 33, 1678−1688