Inorganic Chemistry
Article
and the mixture was swirled thoroughly. The resulting colorless liquid
was decanted from a precipitate of lithium hydroxide and potassium
bromide and dried overnight over solid potassium hydroxide. After
removal of the solvent and distillation under vacuum, pure 1,2-bis(6-
chloropyridin-2-yl)ethane was obtained as a colorless crystalline solid.
Yield: 13.7 g, 93%. 1H NMR (400 MHz, CDCl3, 22 °C), δ: 7.52 (t, J
= 7.7 Hz, 2H), 7.15 (dd, J = 7.9, 0.9 Hz, 2H), 7.05 (dd, J = 7.6, 0.9
Hz, 3H), 7.13 (d, J = 8.2 Hz, 1H), 7.09 (d, J = 8.2 Hz, 1H), 4.17 (t, J
= 12.1 Hz, 1H), 3.50−3.40 (m, 1H), 3.37 (t, J = 11.8 Hz, 1H), 2.55
(t, J = 12.0 Hz, 1H). 1H NMR (400 MHz, CD2Cl2, 22 °C), δ: 8.12 (t,
J = 8.0 Hz, 1H), 7.98 (t, J = 7.8 Hz, 2H), 7.35 (dd, J = 7.6, 1.1 Hz,
2H), 7.24 (t, J = 7.1 Hz, 3H), 4.15 (s, 2H), 3.17 (s, 2H). ESI-MS
calcd. for C17H14Cl2N3O2Pd+ [M + H]+ 467.95. Found: 467.97.
Preparation of Chlorocopper(I) Complex 10. In a glovebox, an
oven-dried 5 mL round-bottomed flask was charged with 10.0 mg of
CuCl, 29.6 mg of 4, and 1 mL of anhydrous degassed dichloro-
methane. The mixture was stirred at room temperature for 10 min,
and the product was formed quantitatively to give a yellowish
solution. Complex 10 could be isolated as a yellow solid upon removal
+
Hz, 2H), 3.20 (s, 4H). ESI-MS Calcd for C12H11Cl2N2 [M + H]+
252.02. Found: 252.04.
1,2-Bis(6-hydroxypyridin-2-yl)ethane bis(hydrogen chloride), 7.
First, 6.6 g of 1,2-bis(6-chloropyridin-2-yl)ethane 6 was dissolved in
25 mL of 30% aqueous HCl. The mixture was transferred to a 50 mL
Schlenk tube and sealed. The reaction was heated in silicon oil bath at
170 °C for 40 h. During the first 10 h of reaction, every 2 h, the
Schlenk tube was removed from oil bath, cooled to room temperature,
and carefully opened to release the pressure of HCl produced in the
reaction. After the first 10 h of reaction the pressure was released
every 5 h. After 40 h of heating the reaction was cooled to room
temperature and transferred to a round-bottomed flask. The excess
HCl was removed on a rotavap and the residue was dried under high
vacuum to give 7 quantitatively as an off-white crystalline solid, which
1
of dichloromethane and drying under high vacuum. H NMR (400
MHz, CD2Cl2, 22 °C), δ: 7.92 (t, J = 7.9 Hz, 1H), 7.79 (t, J = 8.1 Hz,
2H), 7.52−6.18 (m, 6H), 3.62 (s, 4H). 13C NMR (CD2Cl2, 22 °C), δ:
36.0, 106.9, 113.1, 121.1, 140.7, 144.1, 157.5, 158.2, 159.8.
Attempted Preparation of Platinum(II) Complexes. Stirring
mixture of aqueous K2PtCl4 and 4 in did not lead to any changes after
2 days at 22 °C. Similarly, no changes were observed when a mixture
of 4 and Pt2Me4(SMe2)2 was kept in THF solution after 1 day at 22
°C.
1
General Procedure for Aziridination of Olefins with PhINTs
was used in next step without further purification. H NMR (400
Catalyzed by 10 or 10/NaBArF . First, 37.3 mg of PhINTs, 3.00 or
MHz, CD3OD, 22 °C), δ: 8.16 (dd, J = 8.8, 7.4 Hz, 2H), 7.10 (d, J =
7.4 Hz, 2H), 7.06 (d, J = 8.8 Hz, 2H), 3.28 (s, 4H). 13C NMR (151
MHz, CD3OD, 22 °C), δ: 163.12, 151.26, 116.20, 113.51, 32.48. ESI-
4
5.00 equiv of the olefin substrate, and 0.6 mL of degassed anhydrous
dichloromethane were charged to an oven-dried NMR Young tube
under the protection of Ar. The Young tube was gently shaken to
make a suspension before being cooled to 0 °C in ice/water bath.
Then, 0.2 mL of a 25 mM solution of 10 or a solution produced by
+
MS Calcd for C12H13N2O2 [M + H]+ 217.10. Found: 217.14.
Lithium 6,6′-(Ethane-1,2-diyl)bis(pyridin-2-olate), 8. An oven-
dried 500 mL round-bottomed flask was charged under argon
atmosphere with a stir bar, 7.18 g (33 mmol) of compound 7 and 200
mL of anhydrous diethyl ether. Then, 3.0 mL of a 11.0 M n-
butyllithium solution in hexanes was injected to the resulting
suspension via syringe. The reaction was stirred under argon for 1
week. The solvent was then carefully removed on a rotavap, and the
residue was dried under high vacuum to afford the product 8 in
quantitative yield as fine white powder. 1H NMR (400 MHz, CD3OD,
22 °C), δ: 7.26 (dd, J = 8.5, 7.0 Hz, 2H), 6.23 (td, J = 8.2, 0.9 Hz,
4H), 2.82 (s, 4H).
stirring 25 mM 10 with solid NaBArF in dry dichloromethane was
4
injected into the Young tube. The color of the mixture changed to
deep green immediately. The tube was removed periodically from the
ice bath and briefly shaken. After 5−15 min, all solids have dissolved
to produce a clear solution so signifying the end of the reaction. Yields
of the aziridines were determined by 1H NMR integration of the
resulting sharp spectra using 1,4-dioxane (see Figure S14) or 4,4′-
bis(tert-butyl)biphenyl as an internal standard added to reaction
mixtures after the reactions were complete. Using this technique, we
have found that formation of PhI was quantitative, based on the
amount of PhINTs used, as observed for various other pyridine-
supported Cu-based catalysts.16 To confirm the identity of resulting
aziridines, the reaction solutions were passed through a short column
filled with alumina, and the products were eluted with CH2Cl2. The
resulting liquids were taken to dryness, and all volatiles were removed
under high vacuum using a warm water bath. 1H NMR parameters of
the isolated products 14−24 (see below) matched well to those
reported earlier.
[2.1.1]-(2,6)-9,16-Dioxapyridinophane (O2-L), 4. First, 11.56 g (37
mmol) of lithium salt 8 was dissolved in 120 mL of dry 1,3-dimethyl-
2-imidazolidinone (DMI) in a 250 mL round-bottomed flask followed
by the addition of 5.93 g (40 mmol) of 2,6-dichloropyridine. The
mixture was sealed under argon and heated at 185 °C for 3 days
before being cooled to room temperature and quenched by excess
aqueous KOH solution. The mixture was combined with 500 mL of
water and extracted with 50 mL of dichloromethane three times. After
removal of dichloromethane using a rotavap, the residue was distilled
at 110 °C under high vacuum to remove DMI and then at 230 °C
(0.1 mmHg) to collect crude product 4, which was further purified by
recrystallization in EtOAc and hexanes. The pure macrocycle is a
white crystalline solid (1.31 g, 11%), producing crystals suitable for
N-(p-Toluenesulphonyl)-9-azabicyclo[6.1.0]nonane, 14.24
1H NMR (CDCl3, 22 °C), δ: 1.17−1.61 (m, 10H), 1.93−2.02 (m,
3
2H), 2.40 (s, 3H), 2.74 (m, 2H), 7.29 (d, JH−H = 8.4 Hz, 2H), 7.77
3
(d, JH−H = 8.4 Hz, 2H).
N-(p-Toluenesulphonyl)-8-azabicyclo[5.1.0]octane, 15.24 1H
NMR (CDCl3, 22 °C), δ: 1.24−1.12 (m, 1H), 1.62−1.40 (m, 5H),
1.90−1.76 (m, 4H), 2.44 (s, 3H), 2.98−2.92 (m, 2H), 7.32 (d, J = 8.3
Hz, 2H), 7.82 (d, J = 8.3 Hz, 2H).
1
single crystal X-ray diffraction. H NMR (600 MHz, CDCl3, 22 °C),
δ: 7.76 (t, J = 7.9 Hz, 1H), 7.46 (t, J = 7.7 Hz, 2H), 6.81 (dd, J = 7.5,
0.8 Hz, 2H), 6.76 (d, J = 7.9 Hz, 2H), 6.68 (dd, J = 7.9, 0.8 Hz, 2H),
3.24 (s, 4H). 13C NMR (126 MHz, CDCl3, 22 °C), δ: 161.72, 161.20,
158.63, 142.29, 139.21, 119.44, 111.06, 106.63, 35.82. ESI-MS calcd.
N-(p-Toluenesulphonyl)-7-azabicyclo[4.1.0]heptane,
16..24,25 1H NMR (CDCl3, 22 °C), δ: 1.15−1.25 (m, 2H), 1.32−1.42
(m, 2H), 1.72−1.80 (m, 4H), 2.42 (s, 3H), 2.95 (m, 2H), 7.30 (d,
+
for C12H11Cl2N2 [M + H]+ 292.11. Found: 292.20.
Preparation of Dichloropalladium(II) Complex 9. First, 30.0
mg of PdCl2 was suspended in 3 mL of dry acetonitrile in a 10 mL
Schlenk tube. The mixture was sealed and heated at 85 °C for 1 h
until all solids disappeared. The solution was cooled to room
temperature, and 55.0 mg of 4 was added. The reaction was heated at
50 °C for an additional 2 h followed by slow cooling to 0 °C. The
product separated from the solution as reddish powder and was
collected by filtration. The powder was dried under high vacuum to
give 80 mg (94%) of pure 9. Then, 9 mg of the product was dissolved
in 15 mL of DCM in an Erlenmeyer flask and sealed in a bottle
containing 30 mL of pentanes. In a week, crystals were produced
suitable for single-crystal characterization. 1H NMR (500 MHz,
CD2Cl2, −40 °C), δ: 8.06 (t, J = 8.1 Hz, 1H), 8.02 (t, J = 7.8 Hz, 1H),
7.95 (t, J = 7.9 Hz, 1H), 7.39 (d, J = 8.0 Hz, 1H), 7.33 (q, J = 7.8, 7.3
3
3JH−H = 8.4 Hz, 2H), 7.79 (d, JH−H = 8.4 Hz, 2H).
N-(p-Toluenesulphonyl)-6-azabicyclo[3.1.0]hexane, 17.26
1H NMR (CDCl3, 22 °C), δ: 1.50−1.67 (m, 4H), 1.87−1.97 (m,
2H), 2.43 (s, 3H), 3.31 (brs, 2H), 7.30 (d, 3JH−H = 8.2 Hz, 2H), 7.79
3
(d, JH−H = 8.2 Hz, 2H).
2-Phenyl-N-tosylaziridine, 18..23,24,26 1H NMR (CDCl3, 22
°C), δ: 2.38 (d, J = 4.5 Hz, 1H), 2.43 (s, 3H), 2.98 (d, J = 8 Hz, 1H),
3.77 (dd, J = 8, 4.5 Hz, 1H), 7.31−7.19 (m, 5H), 7.33 (d, J = 8 Hz,
2H), 7.87 (d, J = 8 Hz, 2H).
2,2,3-Trimethyl-N-tosylaziridine, 19.8 1H NMR (CDCl3, 22
°C), δ: 1.12 (d, 3JH−H = 5.8 Hz, 3H), 1.26 (s, 3H), 1.67 (s, 3H), 2.42
3
3
(s, 3H), 2.94 (q, JH−H = 5.8 Hz, 1H), 7.32 (d, JH−H = 8.4 Hz, 2H),
3
7.77 (d, JH−H = 8.4 Hz, 2H).
I
Inorg. Chem. XXXX, XXX, XXX−XXX