J. S. Yadav et al. / Tetrahedron Letters 48 (2007) 8306–8310
8309
reactions worked well with NH SCN and NaN to give
2006, 348, 456–462; (b) Vincent, T.; Sylvain, M.; Marie,
G.; Jean-Marc, C.; Damien, P. Adv. Synth. Catal. 2006,
4
3
the corresponding thiocyanides (entries 2, 7, 12, and 21)
and azides (entries 8, 22, and 23). The azido compounds
could be easily converted into amines under standard
conditions. Benzylic alcohols with electron withdrawing
groups such as fluoro or nitro did not react under the
present conditions (entries 24 and 25).
3
48, 2063–2067.
9
. Hongbo, Q.; Noriyuki, Y.; Shigeki, M.; Masakatsu, S.
Angew. Chem., Int. Ed. 2007, 46, 409–413.
1
0. (a) Noji, M.; Ohno, T.; Fuji, K.; Futaba, N.; Tajima, H.;
Ishii, K. J. Org. Chem. 2003, 68, 9340–9347; (b) Noji, M.;
Konno, Y.; Ishii, K. J. Org. Chem. 2007, 72, 5161–5167.
1. Yasuda, M.; Somyo, T.; Baba, A. Angew. Chem., Int. Ed.
2006, 45, 793–796.
1
In conclusion, efficient nucleophilic substitution reac-
tions of diaryl carbinols and aryl alkyl carbinols cata-
lyzed by NbCl5 have been developed. The method
reported here is not only simple to operate but also
yields the products in short durations and in high yields
12. Sanz, R.; Martinez, A.; Miguel, D.; Alvarez-Gutierrez,
J. M.; Rodriguez, F. Adv. Synth. Catal. 2006, 348, 1841–
1
845.
1
3. (a) Yadav, J. S.; Narsaiah, A. V.; Reddy, B. V. S.; Basak,
A. K.; Nagaiah, K. J. Mol. Catal. A 2005, 230, 107–111;
(b) Yadav, J. S.; Narsaiah, A. V.; Basak, A. K.; Goud, P.
R.; Sreenu, D.; Nagaiah, K. J. Mol. Catal. A 2006, 255,
1
2
with water as the only by product. No heating and also
7
no prior derivatization of the benzylic alcohols were
required. Further investigations on the reaction mecha-
nism are currently in progress.
7
8–80; (c) Yadav, J. S.; Reddy, B. V. S.; Eeshwaraiah, B.;
Reddy, P. N. Tetrahedron 2005, 61, 875–878.
4. For reactions catalyzed by TaCl , see: Chandrasekhar, S.;
Ramachander, T.; Shyamsunder, T. Indian J. Chem. B
004, 43B, 813–838, and references cited therein.
1
5
2
Acknowledgment
1
1
1
1
5. Suzuki, K.; Hashimoto, T.; Maeta, H.; Matsumoto, T.
Synlett 1992, 125–128.
6. Howarth, J.; Gillespie, K. Tetrahedron Lett. 1996, 37,
Two of us (D.C.B.) and (K.V.K.) thank CSIR, New
Delhi, for financial assistance.
6
011–6012.
7. Maeta, H.; Nagasawa, T.; Handa, Y.; Takei, T.; Osamura,
Y.; Suzuki, K. Tetrahedron Lett. 1995, 36, 899–902.
8. Wang, R.; Li, B. G.; Huang, T.-K.; Shi, L.; Lu, X.-X.
Tetrahedron Lett. 2007, 48, 2071–2073.
References and notes
1
2
9. Srai, S.; Sudo, Y.; Nishida, A. Synlett 2004, 1104–1106.
0. Yamamoto, M.; Nakazawa, M.; Kishikawa, K.; Kohm-
oto, S. Chem. Commun. 1996, 2353–2354.
1
. (a) Moreno-Manas, M. l.; Gonzalez, A.; Jaime, C.; Lloris,
M. E.; Marquest, J.; Martinez, A.; Siani, A. C.; Vallribera,
A. Tetrahedron 1991, 47, 6511–6520; (b) Cervello, J.;
Marquet, J.; Moreno-Manas, M. J. Chem. Soc., Chem.
Commun. 1987, 644–645; (c) Marquet, J.; Moreno-Manas,
M.; Pacheco, P.; Vallribera, A. Tetrahedron Lett. 1988, 29,
2
2
2
1. Constantino, M. G.; Lacerda, V., Jr.; Aragao, V. Mole-
cules 2001, 6, 770–776.
2. Sudo, Y.; Arai, S.; Nishida, A. Eur. J. Org. Chem. 2006, 3,
7
52–758.
3. (a) Andrade, C. K. Z.; Azevedo, N. R. Tetrahedron Lett.
001, 42, 6473–6476; (b) Andrade, C. K. Z.; Azevedo, N.
1
1
465–1468; (d) Kraus, G. A.; Hon, Y.-S. J. Org. Chem.
985, 50, 4605–4608; (e) Von Boldt, P.; Militzer, H.;
2
Thielecke, W.; Schulz, L. Liebigs Ann. Chem. 1968, 718,
01–114.
. (a) Bisaro, F.; Prestate, G.; Vitale, M.; Poli, G. Synlett
R.; Oliveira, G. R. Synthesis 2002, 928–936; (c) Andrade,
C. K. Z.; Oliveira, G. R. Tetrahedron Lett. 2002, 43, 1935–
1
2
3
4
1
937.
2
2
002, 1823–1826; (b) Jiao, W.; Lash, T. D. J. Org. Chem.
003, 68, 3896–3901; (c) Adams, J. T.; Abramovitch, B.;
2
2
4. Andrade, C. K. Z.; Matos, R. A. F. Synlett 2003, 1189.
5. Howarth, J.; Gillespie, K. Tetrahedron Lett. 1996, 37,
Hauser, C. R. J. Am. Chem. Soc. 1943, 65, 552–554.
6
5
011–6012; For other NbCl catalyzed reactions, see: (a)
. (a) Nguyen, R.-V.; Li, C.-J. J. Am. Chem. Soc. 2005, 127,
Hernandez, H.; Bernes, S.; Quintero, L.; Sansinenea, E.;
Ortiz, A. Tetrahedron Lett. 2006, 47, 1153–1156.
1
7184–17185; (b) Reetz, M. T.; Chatziiosifidis, I.; Sch-
wellnus, K. Angew. Chem., Int. Ed. Engl 1981, 20, 687–
89.
2
6. General experimental procedure: To a solution of benzyl
alcohol (1 mmol) in acetonitrile (3 mL) were added nucle-
6
. For reactions of benzyl acetates, benzyl halides, benzyl
ethers and benzyl carbonates in nucleophilic substitution
reactions see: (a) Iovel, I.; Mertins, K.; Kischel, J.; Zapf,
A.; Beller, M. Angew. Chem., Int. Ed. 2005, 44, 3913–3917;
5
ophile (1.2 mmol) and NbCl (5 mol %) and the mixture
was stirred at room temperature until completion of the
reaction. The reaction mixture was quenched with satu-
3
rated aq NaHCO solution (1 mL) and the product was
(
6
b) Shiina, I.; Suzuki, M. Tetrahedron Lett. 2002, 43,
391–6394; (c) Mertins, K.; Iovel, I.; Kischel, J.; Zapf, A.;
extracted with ethyl acetate. Evaporation of the solvent
gave the crude product, which was purified by column
chromatography. Representative data of selected prod-
ucts: Compound 5b: White solid. IR (KBr) mmax 3444,
Beller, M. Angew. Chem., Int. Ed. 2005, 44, 238–242.
. Coote, S. J.; Davies, S. G.; Middlemiss, D.; Naylor, A.
Tetrahedron Lett. 1989, 30, 3581–3588.
5
6
3
1
024, 2964, 2855, 2372, 1876, 1599, 1509, 1444, 1331,
. (a) Khalaf, A. A.; Roberts, R. M. J. Org. Chem. 1973, 38,
À1
1
254, 1090, 823, 743 cm
.
H NMR (200 MHz,
1
388–1395; (b) Khalaf, A. A.; Roberts, R. M. J. Org.
CDCl
3
+DMSO): d 1.62 (d, J = 7.0 Hz, 3H), 4.20 (q,
Chem. 1972, 37, 4227–4235; (c) Khalaf, A. A.; Roberts, R.
M. J. Org. Chem. 1969, 34, 3571–3574; (d) Khalaf, A. A.;
Roberts, R. M. J. Org. Chem. 1971, 36, 1040–1044; (e)
Sundberg, R. J.; Laurino, J. P. J. Org. Chem. 1984, 49,
J = 7.0, 14.0 Hz, 1H), 6.62 (d, J = 8.6 Hz, 2H), 7.02 (d,
J = 8.6 Hz, 2H), 6.83 (dt, J = 1.1, 8.9 Hz, 2H), 6.93–7.06
(
m, 2H), 7.21–7.30 (m, 1H), 8.57 (br s, 1H, –NH), 10.13 (s,
H, –OH). C NMR (100 MHz, CDCl ): d 153.96,
3
36.45, 135.53, 126.79, 125.42, 119.75, 119.30, 117.95,
13
1
1
1
2
2
49–254; (f) Davis, B. R.; Johnson, S. J.; Woodgate, P. D.
Aust. J. Chem. 1987, 40, 1283–1299.
16.98, 113.87, 113.76, 110.08, 34.69, 21.41. EIMS: m/z
7
8
. Iovel, I.; Mertins, K.; Kischel, J.; Zapf, A.; Beller, M.
Angew. Chem., Int. Ed. 2005, 44, 3913–3917.
. (a) Liu, J.; Muth, E.; Flore, U.; Henkel, G.; Merz, K.;
Sauvageau, E.; Schwake, E.; Dyker, G. Adv. Synth. Catal.
+
38 (M+H) . HRMS for C16
H16NO: Calcd 238.1231;
found, 238.1239. Compound 11b: Yellow liquid. IR (neat):
mmax 3061, 3029, 2924, 2859, 1952, 1601, 1493, 1452, 1094,