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was washed with toluene (3 mL), centrifuged again, and the solu-
tions were combined. To the obtained solution was added n-hexane
(20 mL) and the mixture left standing at 4 °C overnight. The ob-
tained crystalline powder was filtered, washed with pentane, and
127.27, 123.69, 122.16, 21.16, 20.96 ppm. HRMS electrospray: calcd.
for C14H14NO2 [M + H]+ 228.1025; found 228.1021.
2-(2-Acetoxy-2-methylphenyl)pyridine: Purified by chromatogra-
phy on silica gel (Rf = 0.41 in 50 % hexanes/50 % ethyl acetate) and
obtained as yellow oil (30.9 mg, 77 % yield). 1H NMR (400 MHz,
CDCl3): δ = 8.50 (dd, J = 4.7, 1.0 Hz, 1 H), 7.57 (dd, J = 7.7, 0.9 Hz,
1 H), 7.42 (ddd, J = 8.1, 7.2, 2.0 Hz, 1 H), 7.37 (dd, J = 7.6, 1.8 Hz, 1
H), 7.34–7.28 (m, 1 H), 7.23–7.15 (m, 2 H), 2.20 (s, 3 H), 1.96 (s, 3 H)
ppm. 13C{1H} NMR (101 MHz, CDCl3): δ = 168.98, 155.61, 148.24,
146.75, 138.04, 133.57, 132.32, 130.56, 129.36, 125.99, 122.82,
122.60, 20.70, 19.15 ppm. HRMS electrospray: calcd. for C14H14NO2
[M + H]+ 228.1025; found 228.1025.
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dried under vacuum for 24 h. This gave 72 mg of 3 (54 % yield). H
NMR (400 MHz, CD2Cl2): δ = 8.99 (dd, J = 2.4, 0.5 Hz, 1 H), 8.93 (dd,
J = 5.5, 1.3 Hz, 1 H), 7.81 (ddd, J = 8.2, 2.4, 1.3 Hz, 1 H), 7.35 (ddd,
J = 8.2, 5.5, 0.6 Hz, 1 H), 7.31 (s, 2 H), 2.95 (d, J = 2.9 Hz, 12 H), 2.33
(s, 6 H), 1.87–1.77 (m, 12 H) ppm. 13C{1H} NMR (101 MHz, CD2Cl2):
δ = 150.91, 150.10, 141.38, 138.30, 132.81, 125.41, 119.35, 61.21,
44.82, 36.34, 30.75 ppm. HRMS electrospray: calcd. for
C30H39N4PdCl2 [M – Cl– + MeCN]+ 629.1592; found 629.1592.
C28H36Cl3N3Pd (627.37): calcd. C 53.60, H 5.78, N 6.70; found C 53.42,
6-(2-Acetoxyphenyl)nicotinaldehyde: Purified by chromatography
on silica gel (Rf = 0.55 in 50 % hexanes/50 % ethyl acetate) and
H 5.69, N 6.58.
1
General Procedure for the C–H Acetoxylation of 2-Phenylpyr-
idine: 2-Phenylpyridine (100 mg, 0.65 mmol, 1 equiv.), PhI(OAc)2
(229 mg, 0.71 mmol, 1.1 equiv.), and Pd-PEPPSI catalyst (0.02 mmol,
0.03 equiv.) were combined in CH3CN (4 mL) in a 10 mL vial. The
vial was sealed with a Teflon-lined cap, and the reaction mixture
was heated at 92 °C for 12 h. The solvent was removed under vac-
uum, and the resulting oil was purified by chromatography on silica
gel (Rf = 0.30 in 70 % hexanes/30 % ethyl acetate). The product was
obtained as colorless oil (71 mg, 72 % yield). The 1H NMR spectrum
was identical to the one described in the literature.[12a]
obtained as clear oil (5 mg, 15 % yield). H NMR (400 MHz, CD2Cl2):
δ = 10.14 (s, 1 H), 9.19–9.03 (m, 1 H), 8.26–8.16 (m, 1 H), 7.85–7.72
(m, 2 H), 7.51 (td, J = 7.9, 1.6 Hz, 1 H), 7.41 (td, J = 7.6, 1.0 Hz, 1 H),
7.20 (dd, J = 8.1, 1.0 Hz, 1 H), 2.19 (s, 3 H) ppm. 13C{1H} NMR
(101 MHz, CD2Cl2): δ = 190.97, 169.64, 160.95, 152.23, 148.85,
136.47, 132.56, 131.37, 131.12, 130.24, 126.85, 124.24, 123.97,
21.19 ppm. HRMS electrospray: calcd. for C14H12NO3 [M + H]+
242.0817; found 242.0820.
Acknowledgments
Procedure for the C–H Acetoxylation of Other Substrates: Sub-
strates in Table 3 were converted into the monoacetoxylated prod-
ucts applying the same procedure. The reaction conditions and the
GC yields of obtained products are specified in Table 3. The 1H NMR
spectra for previously published products were identical to those
described in the literature.[12]
We are grateful for support from the FP7 Marie Curie Actions
of the European Commission via the Initial Training Network
SMALL (MCITN-238804), the Swedish Research Council, the Knut
and Alice Wallenberg Foundation, and the Royal Physiographic
Society in Lund.
3-Acetoxy-4-(2-pyridyl)benzaldehyde: Purified by chromatogra-
phy on silica gel (Rf = 0.36 in 50 % hexanes/50 % ethyl acetate) and
obtained as a light brown crystalline powder (69.4 mg, 89 % yield).
1H NMR (400 MHz, CDCl3): δ = 10.04 (s, 1 H), 8.73 (ddd, J = 4.8, 1.8,
0.9 Hz, 1 H), 7.89 (s, 1 H), 7.88 (d, J = 1.4 Hz, 1 H), 7.79 (td, J =
7.8,1.8 Hz, 1 H), 7.73–7.66 (m, 1 H), 7.60 (dt, J = 7.9, 1.0 Hz, 1 H),
7.31 (ddd, J = 7.6,4.9,1.1 Hz, 1 H), 2.20 (s, 3 H) ppm. 13C{1H} NMR
(101 MHz, CDCl3): δ = 190.90, 169.10, 154.49, 149.85, 148.66, 138.72,
137.39, 136.58, 131.72, 127.45, 124.33, 123.87, 123.06, 20.93 ppm.
HRMS electrospray: calcd. for C14H11NO3 [M + H]+ 242.0813; found
242.0817.
Keywords: NHC ligands · Palladium · C-H activation ·
Acetoxylation
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ica gel (Rf = 0.30 in 75 % hexanes/25 % ethyl acetate) and obtained
as light yellow oil (44 mg, 52 % yield). 1H NMR (400 MHz, CDCl3):
δ = 8.22 (d, J = 8.5 Hz, 1 H), 8.16 (d, J = 8.4 Hz, 1 H), 7.85 (dd, J =
8.1 Hz, 1 H), 7.82 (dd, J = 7.6, 1.8 Hz, 1 H), 7.74 (ddd, J = 8.5, 6.9,
1.5 Hz, 1 H), 7.66 (d, J = 8.5 Hz, 1 H), 7.57 (ddd, J = 8.1, 6.9, 1.2 Hz,
1 H), 7.51–7.44 (m, 1 H), 7.41 (td, J = 7.5, 1.4 Hz, 1 H), 7.22 (dd, J =
8.0, 1.4 Hz, 1 H), 2.19 (s, 1 H) ppm. 13C{1H} NMR (101 MHz, CDCl3):
δ = 169.63, 156.18, 148.49, 148.13, 136.55, 133.44, 131.26, 130.20,
129.92, 129.71, 127.66, 127.08, 126.83, 126.64, 123.50, 121.73,
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263.0946; found 263.0944.
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2-(2-Acetoxy-4-methylphenyl)pyridine: Purified by chromatogra-
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obtained as yellow oil (65.6 mg, 89 % yield). 1H NMR (400 MHz,
CDCl3): δ = 8.70 (ddt, J = 5.0, 1.9, 1.0 Hz, 1 H, H1), 7.73 (tt, J = 7.7,
1.6 Hz, 1 H), 7.58 (d, J = 7.9 Hz, 1 H), 7.51 (dq, J = 8.0, 1.0 Hz, 1 H),
7.26–7.21 (m, 1 H), 7.18–7.14 (m, 1 H), 6.98 (d, J = 1.8 Hz, 1 H), 2.40
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169.55, 155.65, 149.25, 147.86, 140.36, 136.59, 130.56, 129.86,
Eur. J. Org. Chem. 0000, 0–0
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