K. Iwanami et al. / Tetrahedron Letters 47 (2006) 4741–4744
Table 3. Synthesis of various O-protected cyanohydrinsa
4743
References and notes
O
TMSCN, Fe(OTf)3
EtCN, 0 °C, 30 min
1. (a) Gregory, R. J. H. Chem. Rev. 1999, 3649; (b) Brunel,
J.-M.; Holmes, I. P. Angew. Chem., Int. Ed. 2004, 43,
2752; (c) Chen, F.-X.; Feng, X. Synlett 2005, 892; (d)
Achard, T. R. J.; Clutterbuck, L. A.; North, M. Synlett
2005, 1828.
R
R'
NC OR''
R'
R''OAc
2. Cyanohydrin silyl ethers: (a) Evans, D. A.; Truesdale, L.
K.; Carroll, G. L. J. Chem. Soc., Chem. Commun. 1973,
55; (b) Evans, D. A.; Truesdale, L. K. Tetrahedron Lett.
1973, 49, 4929; (c) Kobayashi, S.; Tsuchiya, Y.; Mukaiy-
ama, T. Chem. Lett. 1991, 537; (d) Kobayashi, S.;
Tsuchiya, Y.; Mukaiyama, T. Chem. Lett. 1991, 541; (e)
Golinski, M.; Brock, C. P.; Watt, D. S. J. Org. Chem.
1993, 58, 159; (f) Yang, Y.; Wang, D. Synlett 1997, 1379;
(g) Saravanan, P.; Anand, R. V.; Singh, V. K. Tetrahedron
Lett. 1998, 39, 3823; (h) Bandini, M.; Cozzi, P. G.;
Melchiorre, P.; Umani-Ronchi, A. Tetrahedron Lett. 2001,
42, 3041; (i) Azizi, V.; Saidi, M. R. Phosphorus, Sulfur,
Silicon Relat. Elem. 2003, 178, 2111; (j) Tian, S.-K.; Hong,
R.; Deng, L. J. Am. Chem. Soc. 2003, 125, 9900; (k) Zhou,
H.; Chen, F.-X.; Qin, B.; Feng, X.; Zhang, G. Synlett
2004, 1077; (l) Karimi, B.; Ma’Mani, L. Org. Lett. 2004, 6,
4813; (m) Ryu, D. H.; Corey, E. J. J. Am. Chem. Soc.
2005, 127, 5384; (n) Fuerst, D. E.; Jacobsen, E. N. J. Am.
Chem. Soc. 2005, 127, 8964; (o) Liu, X.; Qin, B.; Zhou, X.;
He, B.; Feng, X. J. Am. Chem. Soc. 2005, 127, 12224; (p)
Xiong, Y.; Huang, X.; Gou, S.; Huang, J.; Wen, Y.; Feng,
X. Adv. Synth. Catal. 2006, 348, 538; (q) Song, J. J.;
Gallou, F.; Reeves, J. T.; Tan, Z.; Yee, N. K.; Senana-
yake, C. H. J. Org. Chem. 2006, 71, 1273.
R
rt
Run Carbonyl
compound
R00OAc (equiv)
Time of Yieldb/%
the 2nd
step/h
1c
2d
3
4
5
6e
7e
8e
9
10
11
PhCH2CH2CHO MOMOAc (2.2)
5
34
74
78
64
70
84
77
79
64
65
68
MOMOAc (2.2) 0.5
MOMOAc (2.2) 0.5
MEMOAc (1.2)
BOMOAc (1.2)
MOMOAc (2.2)
MEMOAc (1.2)
BOMOAc (1.5)
3
3
1
3
3
3
3
3
PhCHO
Cyclopentanone MOMOAc (2.1)
MEMOAc (1.5)
BOMOAc (1.5)
a Molar ratio of carbonyl compound:Fe(OTf)3:TMSCN = 1:0.05:1.2.
b Isolated yield of purified product.
c Temperature of the 2nd step was ꢀ78 °C.
d Temperature of the 2nd step was 0 °C.
e Nitromethane was used as a solvent.
3. Cyanohydrin esters: (a) Hoffmann, H. M. R.; Ismail, Z.
M.; Hollweg, R.; Zein, A. R. Bull. Chem. Soc. Jpn. 1990,
63, 1807; (b) Okimoto, M.; Chiba, T. Synthesis 1996, 1188;
yield by treatment with basic hydrogen peroxide in
DMSO (Scheme 3).16
´
´
(c) Baeza, A.; Casas, J.; Najera, C.; Sansano, J. M.; Saa, J.
M. Angew. Chem., Int. Ed. 2003, 42, 3413; (d) Baeza, A.;
In conclusion, the present efficient transformation has
the following synthetic advantages: (1) a catalytic
amount of iron(III) triflate promotes both cyanation
and O-protection, in contrast to the known cyanation
of carbonyl compounds, (2) various acetal-types of a
protecting group for the hydroxyl function such as
THP and MOM ether are obtained by using the corre-
sponding acetate, (3) a broad range of aldehydes and
ketones can be applied, (4) mild reaction conditions,
and (5) experimental convenience. Further investigations
to broaden the scope and synthetic applications of this
valuable cyanation are under way in our laboratory.
´
´
Najera, C.; Sansano, J. M.; Saa, J. M. Tetrahedron:
´
Asymmetry 2005, 16, 2385; (e) Baeza, A.; Najera, C.;
Retamosa, M. G.; Sansano, J. M. Synthesis 2005, 2787.
4. Cyanohydrin carbonates: (a) Scholl, M.; Lim, C.-K.; Fu,
G. C. J. Org. Chem. 1995, 60, 6229; (b) Poirier, D.;
Berthiaume, D.; Boivin, R. P. Synlett 1999, 1423; (c)
Deardorff, D. R.; Taniguchi, C. M.; Tafti, S. A.; Kim, H.
Y.; Choi, S. Y.; Downey, K. J.; Nguyen, T. V. J. Org.
Chem. 2001, 66, 7191; (d) Tian, S.-K.; Deng, L. J. Am.
Chem. Soc. 2001, 123, 6195; (e) Tian, J.; Yamagiwa, N.;
Matsunaga, S.; Shibasaki, M. Angew. Chem., Int. Ed.
2002, 41, 3636; (f) Casas, J.; Baeza, A.; Sansano, J. M.;
´
´
Najera, C.; Saa, J. M. Tetrahedron: Asymmetry 2003, 14,
197; (g) Belokon, Y. N.; Blacker, A. J.; Clutterbuck, L. A.;
North, M. Org. Lett. 2003, 5, 4505; (h) Yamagiwa, N.;
Tian, J.; Matsunaga, S.; Shibasaki, M. J. Am. Chem. Soc.
2005, 127, 3413; (i) Lundgren, S.; Wingstrand, E.; Penh-
oat, M.; Moberg, C. J. Am. Chem. Soc. 2005, 127, 11592;
(j) Belokon, Y. N.; Ishibashi, E.; Nomura, H.; North, M.
Chem. Commun. 2006, 1775.
OTHP
OTHP
LiAlH4 (2.0 equiv.)
NH2
Ph
Ph
CN
THF, 0 °C to rt, 1 h
5. Cyanohydrin alkyl ether from acetal: Mukaiyama, T.;
Soga, T.; Takenoshita, H. Chem. Lett. 1989, 997.
6. Greene, T. W.; Wuts, P. G. M. Protective Groups in
Organic Synthesis, 3rd ed.; John Wiley & Sons: New York,
1999, Chapter 2.
84%
Scheme 2. Conversion of nitrile to amine.
7. Iwanami, K.; Oriyama, T. Chem. Lett. 2004, 33, 1324.
8. Iwanami, K.; Aoyagi, M.; Oriyama, T. Tetrahedron Lett.
2005, 46, 7487.
9. Other iron(III) chloride-catalyzed useful reactions of silyl-
substituted necleophiles: (a) Watahiki, T.; Oriyama, T.
Tetrahedron Lett. 2002, 43, 8959; (b) Watahiki, T.;
Akabane, Y.; Mori, S.; Oriyama, T. Org. Lett. 2003, 5,
3045; (c) Iwanami, K.; Seo, H.; Tobita, Y.; Oriyama, T.
OTHP
OTHP
30% H2O2, K2CO3
NH2
Ph
Ph
CN
DMSO, rt, 1 h
O
80%
Scheme 3. Conversion of nitrile to amide.