Abstract
Er(OTf)3 is proposed as a very gentle Lewis acid catalyst in a chemoselective method for the cleavage of alkyl and cyclic acetals and ketals at room temperature in wet nitromethane is presented.
Key words
erbium(III) triflate - Lewis acid catalyst - acetals - ketals
References
1a Anastas PT.
Warner JC.
Green Chemistry: Theory and Practice
Oxford Science Publications;
Oxford:
1998.
1b Collins TC.
Green Chemistry: Frontiers in Chemical Synthesis and Processes
Oxford University Press;
Oxford:
1998.
1c Tundo P.
Anastas P.
St Clair Black D.
Breen J.
Collins T.
Memoli S.
Miyamoto J.
Polyakoff M.
Tumas W.
Pure Appl. Chem.
2000,
72:
1207
2a Bartoli G.
Cupone G.
Dalpozzo R.
De Nino A.
Maiuolo L.
Marcantoni E.
Procopio A.
Synlett
2001,
1897
2b Bartoli G.
Cupone G.
Dalpozzo R.
De Nino A.
Maiuolo L.
Procopio A.
Sambri L.
Tagarelli A.
Tetrahedron Lett.
2002,
43:
5945
2c Dalpozzo R.
De Nino A.
Maiuolo L.
Procopio A.
Tagarelli A.
Sindona G.
Bartoli G.
J. Org. Chem.
2002,
67:
9093
2d Dalpozzo R.
De Nino A.
Maiuolo L.
Procopio A.
Nardi M.
Bartoli G.
Romeo R.
Tetrahedron Lett.
2003,
44:
5621
3a Greene TW.
Wuts PGM.
Protective Groups in Organic Synthesis
3rd Ed.:
John Wiley and Sons;
New York:
1999.
3b Kocienski PJ.
Protecting Groups
1st Ed.:
Georg Thieme Verlag;
Stuttgart:
1994.
4a Steel PG.
J. Chem. Soc., Perkin Trans. 1
2001,
2727
4b Kobayashi S.
Manabe K.
Acc. Chem. Res.
2002,
35:
209
4c Kobayashi S.
Sugiura M.
Kitagawa H.
Lam WW.-L.
Chem Rev.
2002,
102:
2227
5a Marcantoni E.
Nobili F.
Bartoli G.
Bosco M.
Sambri L.
J. Org. Chem.
1997,
62:
4183
5b Carrigan MD.
Sarapa D.
Smith RC.
Wieland LC.
Mohan RS.
J. Org. Chem.
2002,
67:
1027
6 Kobayashi S.
Nagayama S.
Busujima T.
J. Am. Chem. Soc.
1998,
120:
8287
7 Tsuruta H.
Yamaguchi K.
Imamoto T.
Chem. Commun.
1999,
1703
8 Castell P.
Galia M.
Serra A.
Salla JM.
Ramis X.
Polymer
2000,
41:
8465
9 All the chemicals were purchased from commercial sources besides the protected ketals 16 -19 in Table
[2 2c
10 Er(OTf)3 can be purchased from Aldrich e41.00 for 5g (0.008 mol) meanwhile, the prices of Sc(OTf)3 and Yb(OTf)3 sold by Aldrich are e206.4 for 5 g (0.01 mol) and e79 for 5 g (0.008 mol), respectively.
