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16
General Procedure
for the Synthesis of 5a: To a mixture of compound 3a (46 mg, 0.06 mmol) and β-keto
ester 4b
(42 µL, 45
mg, 0.4 mmol) in AcOH (0.2 mL) were added Mn(OAc)3 (128
mg, 0.48 mmol) and Cu(OAc)2 (30 mg, 0.16 mmol). The mixture
in a sealed tube was heated under microwave (Biotage Initiator 8)
at 165 ˚C for 25 min. The reaction mixture was purified
by F-SPE eluted with MeOH-H2O (80:20, 15 mL)
and then with MeOH (20 mL). The MeOH fraction was concentrated to
give 5a (44 mg) in
84% yield.
An analytical sample was obtained by further purification by flash
chromatography (EtOAc-hexane, 7:3). ¹H
NMR (300 MHz, CDCl3): δ = 2.61 (s,
3 H), 3.48 (s, 3 H), 3.76 (s, 3 H), 3.80 (s, 3 H), 6.80-6.86
(m, 3 H), 7.35-7.42 (m, 2 H), 7.80 (d, J = 8.7
Hz, 2 H). ¹³C NMR (75 MHz, CDCl3): δ = 13.9,
51.6, 55.5, 56.4, 110.5, 113.4, 114.0, 115.5, 119.6, 122.7, 126.3,
130.6, 131.7, 139.0, 146.9, 151.5, 158.7, 163.3, 164.1, 191.2. LC-MS
(APCI+): m/z = 879 [M + 1]+.
HRMS (ES+): m/z [M + H]+ calcd
for C30H20O9F17S: 879.0550;
found: 879.0557.
General Procedure
for the Synthesis of 7c: A mixture of 5a (75
mg, 0.085 mmol) and p-tolylboronic acid
(17 mg, 0.125 mmol), Pd(dppf)Cl2 (8.5 mg, 8 mol%)
and Cs2CO3 (55 mg, 0.16 mmol) in co-solvent
of acetone-H2O-HFE7200 (C4F9OEt)
(4:1:4) in a sealed tube was heated under microwave (Biotage Initiator
8) at 130 ˚C for 30 min. The reaction mixture was purified
by flash chromatography (EtOAc-hexanes, 7:3) to give 7c (23 mg) in 59% yield.
¹H
NMR (300 MHz, CDCl3): δ = 2.30 (s,
3 H), 2.60 (s, 3 H), 3.50 (s, 3 H), 3.68 (s, 3 H), 3.77 (s, 3 H),
6.75-6.84 (m, 3 H), 7.12 (d, J = 8.1
Hz, 2 H), 7.22 (m, 2 H), 7.35 (d, J = 2.4
Hz, 1 H), 7.44 (d, J = 4.2 Hz,
1 H), 7.80 (d, J = 9.4 Hz, 2
H).
¹³C NMR (75 MHz, CDCl3): δ = 13.9,
21.3, 51.5, 55.6, 56.7, 111.3, 114.0, 115.3, 122.0, 125.9, 128.4,
128.8, 129.0, 129.4, 130.9, 131.1, 131.8, 134.9, 137.0, 149.2, 156.8, 158.1,
163.6, 163.9, 191.7. LC-MS (APCI+): m/z = 471
[M + 1]+.
HRMS (ES+): m/z [M + H]+ calcd
for C29H27O6: 471.1806; found:
471.1808.
General Procedure for the
Synthesis of 9a: Compound
5a (60
mg, 0.068 mmol), Pd2 (dba)3 (0.32 mg, 5 mol%), JohnPhos
(0.20 mg, 10 mol%) and DBU (252 µL, 0.17 mmol)
were added to the flask under a nitrogen atmosphere. Then p-trifluoromethylaniline (81 µL,
0.08 mmol) in toluene (0.2 mL) was added. The mixture in a sealed
tube was heated under microwave (Biotage Initiator 8) at 130 ˚C
for 30 min. The reaction mixture was purified by flash chromatography (EtOAc-hexanes,
7:3) to give 9a (25 mg) in 69% yield. ¹H NMR
(300 MHz, CDCl3): δ = 2.60 (s, 3 H),
3.47 (s, 3 H), 3.77 (s, 3 H), 3.78 (s, 3 H), 6.18 (s, 1 H), 6.74-6.87
(m, 5 H), 7.09-7.18 (m, 3 H), 7.28-7.34 (m, 1
H), 7.80 (d, J = 9.0 Hz, 2 H).¹³C
NMR (75 MHz, CDCl3): δ = 14.0, 51.5,
55.5, 55.8, 110.9, 113.2, 114.0, 115.2, 116.3, 116.9, 117.3, 119.0, 119.4,
122.0, 126.7, 126.7, 130.9, 131.2, 131.8, 145.4, 149.1, 158.2, 163.5,
164.0, 191.7. LC-MS (APCI+): m/z = 540 [M + 1]+.
HRMS (ES+): m/z [M + H]+ calcd
for C29H25F3NO6: 540.1632;
found: 540.1634.
