ChemComm
Communication
Table 3 Sequential dehydrogenative aromatization/alkenylation sequence Table
4
Sequential
dehydrogenative
aromatization/alkenylation
of N-cyclohexenylacetamidesa
sequence of N-cyclohexenylacetamidesa
a
Condition D: reactions were conducted with N-cyclohexenyl-
t
acetamide, Pd(OAc)2 (0.2 + 0.1 equiv.), PhCO3 Bu (2 + 1 equiv.) and
iPr2S (2.5 mol%) in DME (0.1 M) at 100 1C; alkenes (1.2 equiv.), and
TsOHÁH2O (0.4 equiv.) at 40–80 1C; c-HCl (0.2 mL).
cyclization allows the rapid generation of the corresponding
quinolinones (Table 4).
In summary, we have developed a Pd(II)-catalyzed dehydrogena-
tive aromatization of cyclic N-acetyl enamides and a sequential
cross-coupling process. This simple and efficient approach
offers an unprecedented one-pot route to highly functionalized
arylamines and their derivatives. The synthetic utility of the
one-pot sequence was further demonstrated by its ability to
provide convenient access to quinolinone derivatives.
This research was supported by the National Research
Foundation of Korea (NRF) through general research grants
(NRF-2011-0016436) and the Institute for Basic Science (IBS).
Notes and references
1 (a) The Chemistry of Anilines, Parts 1 and 2, ed. Z. Rappoport, John
Wiley & Sons, New York, 2007; (b) M. Negwer, Organic Chemical
Drugs and their Synonyms, Akademie Verlag GmbH, Berlin, 7th edn,
1994.
2 For selected examples: (a) S. A. Girard, X. Hu, T. Knauber, F. Zhou,
M. O. Simon, G. J. Deng and C. J. Li, Org. Lett., 2012, 14, 5606;
(b) A. Hajra, Y. Wei and N. Yoshikai, Org. Lett., 2012, 14, 5488;
(c) Y. Wei, I. Deb and N. Yoshikai, J. Am. Chem. Soc., 2012, 134, 9098;
(d) P. Horrillo-Martinez, M.-A. Virolleaud and C. Jaekel, ChemCatChem,
2010, 2, 175; (e) H. Neumann, A. J. Wangelin, S. Klaus, D. S. Bing,
D. Grdes and M. Beller, Angew. Chem., Int. Ed., 2003, 42, 4503;
´
( f ) M. Sutter, M.-C. Duclos, B. Guicheret, Y. Raoul, E. Metay and
M. Lemaire, ACS Sustainable Chem. Eng., 2013, 1, 1463; (g) Y. Izawa,
D. Pun and S. S. Stahl, Science, 2011, 333, 209; (h) T. Diao and
S. S. Stahl, J. Am. Chem. Soc., 2011, 133, 14566; (i) T. Diao,
T. J. Wadzinski and S. S. Stahl, Chem. Sci., 2012, 3, 887; ( j) D. Pun,
T. Diao and S. S. Stahl, J. Am. Chem. Soc., 2013, 135, 8213.
3 W. P. Hong, A. V. Iosub and S. S. Stahl, J. Am. Chem. Soc., 2013,
135, 13664.
4 (a) M. D. K. Boele, G. P. F. van Strijdonck, A. H. M. de Vries, P. C. J. Kamer,
J. G. de Vries and P. W. N. M. van Leeuwen, J. Am. Chem. Soc., 2002,
124, 1586; (b) F. W. Patureau and F. Glorius, J. Am. Chem. Soc., 2010,
132, 9982; (c) Y. Aihara and N. Chatani, J. Am. Chem. Soc., 2013, 135, 5308.
a
Condition C: N-cyclohexenylacetamide, Pd(OAc)2 (0.2 + 0.1 equiv.),
t
PhCO3 Bu (2 + 1 equiv.) and iPr2S (2.5 mol%) in DME (0.1 M) at 100 1C;
b
alkenes (1.2-1.5 equiv.), and TsOHÁH2O (0.4 equiv.) at 40–80 1C. Ratio
c
of positional isomers. Ratio of mono- and di-olefinated products.
to the quinolinone moiety, which constitutes the core of a wide
variety of naturally occurring compounds and privileged
medicinal scaffolds.10 Indeed, the sequential dehydrogenation–
alkenylation process followed by in situ acid-mediated
This journal is ©The Royal Society of Chemistry 2014
Chem. Commun., 2014, 50, 3227--3230 | 3229