4332
F.J. Robertson et al. / Tetrahedron 67 (2011) 4327e4332
yield that was homogeneous as judged by 1H NMR spectroscopy. 1H
NMR (CDCl3, 500 MHz)
110.5, 107.6, 29.1, 8.4; IR (film, cmꢁ1) 3405, 3055, 2921, 1620, 1583,
1495, 1458, 1384, 1332, 1241, 1157, 1008, 744.
d
7.61e7.60 (d, J¼7.5 Hz, 1H), 7.32e7.31 (m,
1H), 7.27e7.24 (m, 1H), 7.20e7.18 (m, 1H), 7.13e7.10 (m, 2H),
6.80e6.77 (m, 1H), 6.71e6.70 (m, 2H), 4.02 (s, 2H), 3.72 (s, 3H), 3.66
1.9%
3.8%
1.6%
2.8%
H
Me
Me
(br s, 2H); 13C NMR (CDCl3,125 MHz)
d 145.1,137.5,130.7,128.0,127.6,
H
H
NH2
127.2,125.7,122.0,119.4,119.1,118.9,116.0,112.3,109.5, 32.9, 28.3; IR
(film, cmꢁ1) 3440, 3363, 3051, 2924, 1618, 1583, 1549, 1493, 1424,
1372, 1327, 1251, 1198, 1154, 1130, 1058, 1011, 909, 741. Exact mass
calcd for [MþH]þ requires m/z 237.1392; found 237.1393 (ESþ).
NH2
N
N
H
H
2.5%
3.8%
Me
5.2%
H
H
5.1.21. Preparation of 19j. The compound 19j was prepared fol-
lowing the general procedure and isolated by silica gel column
chromatography (10% EtOAc/pentanes) as a pale yellow solid in 79%
yield that was homogeneous as judged by 1H NMR spectroscopy. 1H
NH
H2N
NMR (CDCl3, 500 MHz)
d
7.40e7.39 (d, J¼8.0 Hz, 1H), 7.29e7.28 (m,
Acknowledgements
1H), 7.18e7.15 (m, 1H), 7.07e7.01 (m, 3H), 6.72e6.69 (m, 1H),
6.67e6.65 (m, 1H), 3.97 (s, 2H), 3.70 (s, 3H), 3.67 (br s, 2H), 2.35 (s,
The authorsare gratefulto DartmouthCollege and the Walterand
Constance Burke Foundation for their generous financial support.
3H); 13C NMR (CDCl3, 125 MHz)
d 145.0, 136.9, 134.2, 130.0, 128.1,
127.2, 125.9, 120.9, 119.2, 118.8, 118.6, 115.7, 108.8, 107.5, 29.8, 27.4,
10.6; IR (film, cmꢁ1) 3439, 3365, 3048, 2910, 1619, 1582, 1492, 1472,
1456, 1409, 1367, 1332, 1289, 1249, 1183, 1153, 1055, 1016, 922, 839,
741. Exact mass calcd for [MþH]þ requires m/z 251.1548; found
251.1556 (ESþ).
References and notes
1. Robertson, F.; Wu, J. Org. Lett. 2010, 12, 2668.
2. Han, X.; Zhang, Y.; Wu, J. J. Am. Chem. Soc. 2010, 132, 4104.
3. Han, X.; Wu, J. Org. Lett. 2010, 12, 5780.
4. (a) Numata, A.; Takahashi, C.; Ito, Y.; Takada, T.; Kawai, K.; Usami, Y.; Matsu-
mura, E.; Imachi, M.; Ito, T.; Hasegawa, T. Tetrahedron Lett. 1993, 34, 2355;
(b) Ratnayake, A. S.; Yoshida, W. Y.; Mooberry, S. L.; Hemscheidt, T. K. J. Org.
Chem. 2001, 66, 8717; (c) Nielsen, K. F.; Smedsgaard, J. J. Chromatogr., A 2003,
102, 111; (d) Anderson, B.; Smedsgaard, J.; Frisvad, J. C. J. Agric. Food Chem. 2004,
52, 2421; (e) Dalsgaard, P. W.; Blunt, J. W.; Munro, M. H. G.; Frisvad, J. C.;
Christophersen, C. J. Nat. Prod. 2005, 68, 258; (f) Siengalewicz, P.; Gaich, T.;
Mulzer, J. Angew. Chem., Int. Ed. 2008, 47, 8170.
5.1.22. Preparation of 19k. The compound 19k was prepared fol-
lowing the general procedure and isolated by silica gel column
chromatography (10% EtOAc/pentanes) as a pale yellow solid in 73%
yield that was homogeneous as judged by 1H NMR spectroscopy. 1H
NMR (CDCl3, 500 MHz)
d 7.21e7.19 (m, 2H), 7.13e7.10 (m, 1H), 7.02
(d, J¼2.5 Hz, 1H), 6.92e6.90 (m, 1H), 6.81e6.77 (m, 1H), 6.72e6.70
5. (a) Jadulco, R.; Edrada, R. A.; Ebel, R.; Berg, A.; Schaumann, K.; Wray, B.; Steube, K.;
Proksch, P. J. Nat. Prod. 2004, 67, 78; (b) Hayashi, H.; Matsumoto, H.; Akiyama, K.
Biosci. Biotechnol. Biochem. 2004, 68, 753.
(m, 1H), 6.67 (s, 1H), 3.98 (s, 2H), 3.84 (s, 3H), 3.69 (s, 3H), 3.64 (br s,
2H); 13C NMR (CDCl3, 125 MHz)
d 154.0, 145.1, 132.9, 130.6, 128.2,
6. (a) Crawley, S. L.; Funk, R. L. Org. Lett. 2003, 5, 3169; (b) May, J. A.; Zeidan, R. K.;
Stoltz, B. M. Tetrahedron Lett. 2003, 44, 1203; (c) May, J. A.; Stoltz, B. Tetrahedron
2006, 62, 5262; (d) Crawley, S. L.; Funk, R. L. Org. Lett. 2006, 8, 3995; (e) George,
J. H.; Adlington, R. M. Synlett 2008, 2093.
7. (a) Yang, J.; Wu, H.; Shen, L.; Qin, Y. J. Am. Chem. Soc. 2007, 129, 13794; (b) Liu, P.;
Seo, J. H.; Weinreb, S. M. Angew. Chem., Int. Ed. 2010, 49, 2000; (c) Zuo, Z.; Xie,
W.; Ma, D. J. Am. Chem. Soc. 2010, 132, 13226.
127.8, 127.6, 125.7, 118.9, 116.0, 112.2, 111.6, 110.3, 101.1, 56.1, 33.1,
28.4; IR (film, cmꢁ1) 3440, 3365, 2996, 2938, 2830,1620,1580,1491,
1454, 1423, 1377, 1302, 1257, 1222, 1172, 1136, 1057, 1034, 899, 836,
796, 752. Exact mass calcd for [MþH]þ requires m/z 267.1497;
found 267.1500 (ESþ).
8. Sabahi, A.; Novikov, A.; Rainier, J. D. Angew. Chem., Int. Ed. 2006, 45, 4317.
9. Steinhagen, H.; Corey, E. J. Angew. Chem., Int. Ed. 1999, 38, 1928.
10. For leading references see: (a) Nishimoto, Y.; Onishi, Y.; Yasuda, M.; Baba, A.
Angew. Chem., Int. Ed. 2009, 48, 9131; (b) Yasuda, M.; Somyo, T.; Baba, A. Angew.
Chem., Int. Ed. 2006, 45, 793.
11. For leading references see: (a)Sanz, R.;Martínez, A.;Miguel, D.;Alvarez-Gutierrez,
J.M.;Rodríguez,F. Adv. Synth. Catal.2006, 348,1841; (b) Qiao, Z.; Shafiq,Z.;Liu,L.;Yu,
Z.-B.; Zheng, Q.-Y.; Wang, D.; Chen, Y.-J. Angew. Chem., Int. Ed. 2010, 49, 7294.
12. (a) Cozzi, P. G.; Zoli, L. Angew. Chem., Int. Ed. 2008, 47, 4162; (b) Cozzi, P. G.; Zoli,
L. Green. Chem. 2007, 9, 1292.
5.1.23. Preparation of 19l. The compound 19l was prepared fol-
lowing the general procedure and isolated by silica gel column
chromatography (10% EtOAc/pentanes) as a pale yellow solid in 64%
yield that was homogeneous as judged by 1H NMR spectroscopy. 1H
ꢀ
ꢀ
NMR (CDCl3, 500 MHz)
d 7.39 (s, 1H), 7.21e7.17 (m, 2H), 7.13e7.06
(m, 2H), 6.80e6.76 (m, 1H), 6.71e6.69 (m, 1H), 6.64 (s, 1H), 3.98 (s,
2H), 3.69 (s, 3H), 3.64 (br s, 2H), 2.46 (s, 3H); 13C NMR (CDCl3,
13. (a) Olah, G. A.; Farooq, O.; Farnia, S. M. F.; Olah, J. A. J. Am. Chem. Soc. 1988, 110,
2560; (b) Prakash, G. K. S.; Mathew, T.; Panja, C.; Alconcel, S.; Vaghoo, H.; Do, C.;
Olah, G. A. Proc. Natl. Acad. Sci. U.S.A. 2007, 104, 3703; (c) Prakash, G. K. S.;
Mathew, T.; Panja, C.; Vaghoo, H.; Venkataraman, K.; Olah, G. A. Org. Lett. 2007,
9, 179; (d) Yan, P.; Batamack, P.; Prakash, G. K. S.; Olah, G. A. Catal. Lett. 2005,
125 MHz)
d 145.0, 135.9, 130.6, 128.4, 128.2, 127.5, 127.3, 125.8,
123.6, 118.9, 118.9, 116.0, 111.7, 109.2, 32.9, 28.2, 21.7; IR (film, cmꢁ1
)
3362, 3021, 2914, 1619, 1492, 1456, 1376, 1304, 1147, 1054, 791, 750.
Exact mass calcd for [MþH]þ requires m/z 251.1548; found 251.1548
(ESþ).
€ €
103, 165; (e) Parakash, G. K. S.; Yan, P.; Torok, B.; Bucsi, I.; Tanaka, M.; Olah, G. A.
Catal. Lett. 2003, 85, 1.
14. Trost, B. M.; Quancard, J. J. Am. Chem. Soc. 2006, 128, 6314.
15. (a) Bell, M. G.; Gernert, D. L.; Grese, T. A.; Belvo, M. D.; Borromeo, P. S.; Kelley, S.
A.; Kennedy, J. H.; Kolis, S. P.; Lander, P. A.; Richey, R; Scott Sharp, V.; Ste-
phenson, G. A.; Williams, J. D.; Hannah, Yu; Zimmerman, K. M.; Steinberg, M. I.;
Jadhav, P. K. J. Med. Chem. 2007, 50, 6443; (b) Sanz, R.; Miguel, D.; Alvarez-
Gutierrez, J. M.; Rodriguez, F. Synlett 2008, 975.
16. (a) Sanz, R.; Martinez, A.; Alvarez-Gutierrez, J. M.; Rodriguez, F. Eur. J. Org. Chem.
2006, 1383; (b) Bras, J. L.; Muzart, J. Tetrahedron 2007, 63, 7942.
17. Chung, J. Y. L.; Mancheno, D.; Dormer, P. G.; Variankaval, N.; Ball, R. G.; Tsou, N.
N. Org. Lett. 2008, 10, 3037.
5.1.24. Characterization of 23. The compound 23 was isolated from
the reaction depicted in Table 1 entry 5. Purification was performed
by silica gel column chromatography (10% EtOAc/pentanes). The
product was isolated as a white solid in 16% yield that was homo-
geneous as judged by 1H NMR spectroscopy. 1H NMR (CD2Cl2,
500 MHz)
d 7.96 (br s, 1H), 7.49e7.48 (m, 1H), 7.19e7.17 (m, 1H),
7.11e7.10 (d, J¼8.0 Hz, 2H), 7.08e7.02 (m, 2H), 6.78e6.74 (td,
18. (a) Iyer, R.; Jackson, A. H.; Shannon, P. V. R. J. Chem. Soc., Perkin Trans. 2 1973,
878; (b) Jackson, A. H.; Smith, P. J. Chem. Soc., Chem. Commun. 1967, 265; (c)
Jackson, A. H.; Naidoo, B.; Smith, P. Tetrahedron 1968, 24, 6119; (d) Williams, J.
R.; Unger, L. R. J. Chem. Soc., Chem. Commun. 1970, 1605.
J1¼7.5 Hz, J2¼1.0 Hz, 1H), 6.71e6.69 (d, J¼7.5 Hz, 1H), 4.00 (s, 2H),
3.67 (br s, 2H), 2.34 (s, 3H); 13C NMR (CD2Cl2, 125 MHz)
d 145.2,
135.7, 132.3, 130.5, 129.4, 128.2, 123.6, 121.4, 119.1, 119.1, 118.3, 116.3,