460
Q. Teng et al.
Paper
Synthesis
13C NMR (125 MHz, CDCl3): δ = 142.2, 141.7, 138.6, 129.0, 128.8,
MS (EI): m/z (%), 3ja = 308 (100, [M+]), 310 (100), 281 (25), 228 (65),
127.1, 125.8, 125.7, 35.6, 31.6, 31.2, 22.6, 14.0.
226 (45), 207 (65).
MS (EI): m/z (%) = 370 (95, [M+]), 313 (100), 256 (30).
3-(1,5-Diphenylpenta-1,4-diyn-3-yl)pentane-2,4-dione (5aa)
Anal. Calcd for C28H34: C, 90.75; H, 9.25. Found: C, 90.91; H, 9.09.
A reaction mixture of bispropargyl alcohol 1a (116 mg, 0.5 mmol),
1,3-diketone 2a (55 mg, 0.55 mmol), TfOH (7.5 mg, 10 mol%), and
PhCl (2 mL) was placed in a 10 mL flask and stirred at 50 °C in air,
monitoring the progress of the reaction periodically by TLC. Upon
completion of the reaction, the solvent was removed under vacuum.
The crude product was purified by flash column chromatography on
silica gel (PE–EtOAc, 20:1) to afford the intermediate 5aa; yield: 149.2
mg (95%); yellow solid; mp 72.1–73 °C.
4,4′′-Di-tert-butyl-1,1′:3′,1′′-terphenyl (3ea)19
Yield: 157.3 mg (92%); white solid; mp 142–146 °C.
1H NMR (500 MHz, CDCl3): δ = 7.85 (s, 1 H), 7.64 (dd, J = 8.3, 2.7 Hz, 4
H), 7.60 (dd, J = 8.2, 1.4 Hz, 2 H), 7.56–7.52 (m, 5 H), 1.69–1.20 (m, 18
H).
13C NMR (125 MHz, CDCl3): δ = 150.4, 141.6, 138.4, 129.0, 126.9,
125.9, 125.7, 34.5, 31.4.
1H NMR (500 MHz, CDCl3): δ = 7.41 (dd, J = 7.5, 1.9 Hz, 4 H), 7.33–7.28
MS (EI): m/z (%) = 342.2 (50, [M+]), 327.2 (100), 156 (20), 142 (10),
128 (25), 57.0 (40).
(m, 6 H), 4.65 (d, J = 10.1 Hz, 1 H), 4.23 (d, J = 10.1 Hz, 1 H), 2.35 (s, 6
H).
13C NMR (125 MHz, CDCl3): δ = 200.5, 131.7, 128.6, 128.2, 122.2, 84.0,
83.2, 72.5, 29.7, 24.2.
4,4′′-Dimethoxy-1,1′:3′,1′′-terphenyl (3fa)20
Yield: 101.5 mg (70%); yellow solid; mp 184–190 °C.
HRMS (ESI): m/z [M + Na]+ calcd for C22H18O2Na: 337.1204; found:
337.1199.
1H NMR (500 MHz, CDCl3): δ = 7.72 (s, 1 H), 7.58 (d, J = 8.8 Hz, 4 H),
7.51–7.41 (m, 3 H), 7.00 (d, J = 8.8 Hz, 4 H), 3.86 (s, 6 H).
Conversion of 5aa into 3aa
13C NMR (125 MHz, CDCl3): δ = 159.3, 141.4, 133.9, 129.1, 128.3,
A reaction mixture of the intermediate 5aa (149.2 mg, 0.47 mmol)
and TfOH (7.05 mg, 0.047 mmol, 10 mol%), and PhCl (2 mL) was
placed in a 10 mL flask and stirred at 110 °C in air, monitoring the
progress of the reaction periodically by TLC. Upon completion of the
reaction, the solvent was removed under vacuum. The crude product
was purified by flash column chromatography on silica gel (PE–
EtOAc, 20:1) to afford the substituted benzene 3aa; yield: 99.5 mg
(92%).
125.3, 125.2, 114.3, 55.4.
MS (EI): m/z (%) = 290 (100, [M+]), 275 (30), 247 (25), 207 (14), 145
(15), 123 (8).
3,3′′-Dimethyl-1,1′:3′,1′′-terphenyl (3ga)21
Yield: 110.9 mg (86%); yellow oil.
1H NMR (500 MHz, CDCl3): δ = 7.83 (d, J = 1.6 Hz, 1 H), 7.61–7.59 (m, 2
H), 7.52 (dd, J = 18.9, 8.2 Hz, 5 H), 7.39 (t, J = 7.5 Hz, 2 H), 7.23 (d,
J = 7.5 Hz, 2 H), 2.48 (s, 6 H).
Acknowledgment
13C NMR (125 MHz, CDCl3): δ = 141.9, 141.3, 138.4, 129.1, 128.7,
128.2, 128.1, 126.2, 126.1, 124.4, 21.6.
MS (EI): m/z (%) = 258 (100, [M+]), 242 (10), 228 (10), 165 (15).
We thank the Ministry of Education of China (IRT1225), National Nat-
ural Science Foundation of China (21362002 and 81260472), State
Key Laboratory Cultivation Base for the Chemistry and Molecular En-
gineering of Medicinal Resources, Ministry of Science and Technology
of China (CMEMR2014-A02 and CMEMR2012-A20), and Guangxi’s
Medicine Talented Persons Small Highland Foundation (1306) for
financial support.
4,4′′-Difluoro-1,1′:3′,1′′-terphenyl (3ha)
Yield: 86.5 mg (65%); white solid; mp 92–95 °C.
1H NMR (500 MHz, CDCl3): δ = 7.69 (s, 1 H), 7.63–7.55 (m, 4 H), 7.55–
7.49 (m, 3 H), 7.15 (t, J = 8.7 Hz, 4 H).
13C NMR (125 MHz, CDCl3): δ = 163.6, 161.6, 140.9, 137.2, 129.3,
128.82, 128.75, 126.0, 125.9, 115.8, 115.6, 29.7.
MS (EI): m/z (%) = 266 (100, [M+]), 257 (50), 244 (20), 170 (5), 133
(15).
Supporting Information
Supporting information for this article is available online at
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Anal. Calcd for C18H12F2: C, 81.19; H, 4.54. Found: C, 80.98; H, 4.71.
4,4′′-Dibromo-1,1′:3′,1′′-terphenyl (3ia) and 4-Bromo-1,1′:3′,1′′-
References
terphenyl (3ja)22
(1) For selected reviews, see: (a) Jun, C. H. Chem. Soc. Rev. 2004, 33,
610. (b) Park, Y. J.; Park, J. W.; Jun, C. H. Acc. Chem. Res. 2008, 41,
222. (c) Murakami, M.; Matsuda, T. Chem. Commun. 2011, 47,
1100.
(2) Ten Brink, G.-J.; Arends, I. W. C. E.; Sheldon, R. A. Chem. Rev.
2004, 104, 4105.
(3) Fuson, R. C.; Bull, B. A. Chem. Rev. 1934, 15, 275.
(4) (a) Mehta, G.; Reddy, K. S. Tetrahedron Lett. 1996, 37, 2289.
(b) Mehta, G.; Venkateswaran, R. V. Tetrahedron 2000, 56, 1399.
(c) Ishihara, K.; Yano, T. Org. Lett. 2004, 6, 1983.
3ia/3ja (1.52:1); total yield: 116.4 mg (60%); white solid.
1H NMR (500 MHz, CDCl3): δ = 7.84 (s, 1 H, 3ia), 7.78 (s, 1 H, 3ja), 7.67
(dd, J = 12.5, 5.2 Hz, 4 H of 3ia and 3 H of 3ja), 7.61–7.59 (m, 4 H, 3ja),
7.55–7.51 (m, 3 H of 3ia and 1 H of 3ja), 7.49 (t, J = 7.6 Hz, 4 H of 3ia
and 2 H of 3ja), 7.39 (t, J = 7.4 Hz, 2 H, 3ja).
13C NMR (125 MHz, CDCl3): δ = 142.0, 141.8, 141.2, 141.0, 140.6,
140.1, 131.9, 129.3, 129.2, 128.82, 128.78, 127.5, 127.4, 127.3, 127.2,
126.5, 126.14, 126.10, 125.89, 125.85, 121.7.
MS (EI): m/z (%), 3ia = 388 (90, [M+]), 386 (50), 389 (48), 288 (53), 113
(40).
© Georg Thieme Verlag Stuttgart · New York — Synthesis 2016, 48, 455–461