13 was identified by high resolution MS (M ꢀ 1 obs. 107.0606,
calc. 107.0609) and by comparison of its 1H NMR spectrum to
that of a commercially available sample in CD2Cl2 (–NHCH3
d 2.87 ppm, doublet, 5.1 Hz; aromatic C3H d 6.48 ppm,
doublet, 6.3 Hz; aromatic C2H d 8.17 ppm, doublet, 6.3 Hz).
Although intermediate 4 was never isolated, its formation
was evident from the GC/MS of the dehydrogenation samples.
The mass spectrum of the peak representing intermediate 4
contains the requisite molecular ion peak (m/z 204), large
peaks (93 and 106, corresponding to pyridine–CH3 and pyr-
idine–CH2CH3) that are in common with the MS of 5 and
consistent with an alkylpyridine, and large peaks (98 and 112,
corresponding to piperidyl–CH3 and piperidyl–CH2CH3) that
are in common with the MS of 3 and consistent with an
alkylpiperidine. The final product 5 was identified by compar-
15 G. Lunn and E. B. Sansone, J. Org. Chem., 1986, 51, 513–517.
16 G. Lunn, J. Org. Chem., 1992, 57, 6317–6320.
17 W. G. Mallard, National Institute of Standards and Technology,
2005.
18 S. Nishimura, in Handbook of heterogeneous catalytic hydrogena-
tion for organic synthesis, John Wiley & Sons, New York, 2001,
ch. 12.
19 H. Adkins, L. F. Kuick, M. Farlow and B. Wojcik, J. Am. Chem.
Soc., 1934, 56, 2425–2428.
20 M. Freifelder and G. R. Stone, J. Org. Chem., 1961, 26, 3805–3808.
21 F. Glorius, N. Spielkamp, S. Holle, R. Goddard and C. W.
Lehmann, Angew. Chem., Int. Ed., 2004, 43, 2850–2852.
22 F. Glorius, Org. Biomol. Chem., 2005, 3, 4171–4175.
23 S. M. Lu, X. W. Han and Y. G. Zhou, Chin. J. Org. Chem., 2005,
25, 634–640.
24 C. S. Chin, Y. S. Park and B. Lee, Catal. Lett., 1995, 31,
239–243.
25 C. Bianchini, V. Dal Santo, A. Meli, S. Moneti, M. Moreno, W.
Oberhauser, R. Psaro, L. Sordelli and F. Vizza, J. Catal., 2003,
213, 47–62.
1
ison of its H, 13C and mass spectra to those in a database.43
26 R. Kuwano, J. Synth. Org. Chem. Jpn., 2007, 65, 109–118.
27 L. Hegedus, V. Hada, A. Tungler, T. Mathe and L. Szepesy, Appl.
Catal. A: Gen., 2000, 201, 107–114.
28 S. Kotrel and M. Ernst, Ger. Pat., DE 102006058624 A1, 2007.
29 J. Heveling, E. Armbruster and W. Siegrist, PCT Int. Appl. Pat.,
WO 9422824 A1, 1994.
30 S. Horrobin and R. J. Young, US Pat., 2765311, 1956.
31 H. Adkins and L. G. Lundsted, J. Am. Chem. Soc., 1949, 71,
2964–2965.
32 A. P. Terent’ev and S. M. Gurvich, Sb. Statei Obshch. Khim., 1953,
2, 1105–1111.
The half-lives for the dehydrogenation of 1b, 1d and 3 were
calculated from the slopes of the plots of log [1b], log[1d] and
log([5] + 0.5[4]) vs. time. These plots were linear for 5, 5 and 3
half-lives, respectively, although the plot for 1b had one outlier
at 30 min. The half lives for the dehydrogenation of 1c and 1e
were estimated to be 12 min and B100 h, respectively, based
upon the first data point for each (59% dehydrogenation
after 15 min for 1c and 2.1% in 3.5 h for 1e) and assuming
first-order behaviour.
33 H. Taguchi, T. Ohishi and H. Kugita, Tetrahedron Lett., 1968,
5763–5766.
34 C. Hansch, A. Leo and R. W. Taft, Chem. Rev., 1991, 91, 165–195.
35 G. A. Vedage and J. N. Armor, Ger. Pat., DE 19602679 A1, 1996.
36 G. P. Pez, A. R. Scott, A. C. Cooper, H. Cheng, L. D. Bagzis and J.
B. Appleby, WO Appl. Pat., 2004-US14034 2005000457, 2005.
37 H. Adkins and H. L. Coonradt, J. Am. Chem. Soc., 1941, 63,
1563–1570.
Acknowledgements
The authors gratefully acknowledge financial support from the
Natural Sciences and Engineering Research Council of Cana-
da, the Ontario Centres of Excellence (Energy), and Chrysler
Canada.
38 F. E. King, J. A. Barltrop and R. J. Walley, J. Chem. Soc., 1945,
277–280.
39 H. J. Teuber and G. Schmitt, Chem. Ber., 1969, 102, 713–716.
40 B. S. Lane, M. A. Brown and D. Sames, J. Am. Chem. Soc., 2005,
127, 8050–8057.
References
1 M. Ni, Energ. Explor. Exploit., 2006, 24, 197–209.
2 D. K. Ross, Vacuum, 2006, 80, 1084–1089.
3 E. M. Gray, Adv. Appl. Ceram., 2007, 106, 25–28.
4 S. Satyapal, J. Petrovic, C. Read, G. Thomas and G. Ordaz, Catal.
Today, 2007, 120, 246–256.
5 O. K. Davtyan and I. I. Burshtein, Arm. Khim. Zh., 1971, 24,
1044–1049.
6 G. Cacciola, N. Giordano and G. Restuccia, Int. J. Hydrogen
Energy, 1984, 9, 411–419.
7 A. Touzani, D. Klvana and G. Belanger, Int. J. Hydrogen Energy,
1984, 9, 929–936.
8 D. Klvana, A. Touzani, J. Chaouki and G. Belanger, Int. J.
Hydrogen Energy, 1991, 16, 55–60.
9 G. P. Pez, A. R. Scott, A. C. Cooper and H. Cheng, EP Pat. Appl.,
1475349, 2004.
10 G. P. Pez, A. R. Scott, A. C. Cooper and H. Cheng, US Pat.,
7101530, 2006.
41 M. Mokotoff, J. Heterocycl. Chem., 1973, 10, 1063–1065.
42 M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E. Scuseria, M. A.
Robb, J. R. Cheeseman, J. A. Montgomery, Jr., T. Vreven, K. N.
Kudin, J. C. Burant, J. M. Millam, S. S. Iyengar, J. Tomasi, V.
Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G. A.
Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R.
Fukuda, J. Hasegawa, M. Ishida, T. Nakajima, Y. Honda, O.
Kitao, H. Nakai, M. Klene, X. Li, J. E. Knox, H. P. Hratchian, J.
B. Cross, V. Bakken, C. Adamo, J. Jaramillo, R. Gomperts, R. E.
Stratmann, O. Yazyev, A. J. Austin, R. Cammi, C. Pomelli, J.
Ochterski, P. Y. Ayala, K. Morokuma, G. A. Voth, P. Salvador, J.
J. Dannenberg, V. G. Zakrzewski, S. Dapprich, A. D. Daniels, M.
C. Strain, O. Farkas, D. K. Malick, A. D. Rabuck, K. Raghava-
chari, J. B. Foresman, J. V. Ortiz, Q. Cui, A. G. Baboul, S.
Clifford, J. Cioslowski, B. B. Stefanov, G. Liu, A. Liashenko, P.
Piskorz, I. Komaromi, R. L. Martin, D. J. Fox, T. Keith, M. A.
Al-Laham, C. Y. Peng, A. Nanayakkara, M. Challacombe, P. M.
W. Gill, B. G. Johnson, W. Chen, M. W. Wong, C. Gonzalez and
J. A. Pople, GAUSSIAN 03 (Revision C.02), Gaussian, Inc.,
Wallingford, CT, 2004.
11 G. P. Pez, A. R. Scott, A. C. Cooper and H. Cheng, US Pat.,
2005002857, 2005.
12 D. E. Schwarz, T. M. Cameron, P. J. Hay, B. L. Scott, W. Tumas
and D. L. Thorn, Chem. Commun., 2005, 5919–5921.
13 E. Clot, O. Eisenstein and R. H. Crabtree, Chem. Commun., 2007,
2231–2233.
43 T. Saito, K. Hayamizu, M. Yanagisawa, O. Yamamoto, N.
Wasada, K. Someno, S. Kinugasa, K. Tanabe, T. Tamura and J.
Hiraishi, National Institute of Advanced Industrial Science and
Technology, 2007.
14 A. Moores, M. Poyatos, Y. Luo and R. H. Crabtree, New J.
Chem., 2006, 30, 1675–1678.
44 M. Mokotoff and S. T. Hill, J. Heterocycl. Chem., 1988, 25, 65–71.
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