TY - JOUR
T1 - Palladium-catalyzed three-component coupling reactions of 2-(cyanomethyl)phenol, aryl halides, and carbon monoxide
AU - Murai, Masahito
AU - Okamoto, Kazuhiro
AU - Miki, Koji
AU - Ohe, Kouichi
N1 - Funding Information:
This work was financially supported by Nissan Chemical Industries, Ltd. and Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology, Japan .
Publisher Copyright:
© 2015 Elsevier Ltd. All rights reserved.
PY - 2015/5/30
Y1 - 2015/5/30
N2 - Three-component coupling reactions of 2-(cyanomethyl)phenol, aryl halides, and carbon monoxide (CO) in orthogonal-tandem catalysis were investigated. In the reactions, 2-(cyanomethyl)phenyl esters, which are produced through Pd(PPh3)4-catalyzed alkoxycarbonylation of aryl halides with 2-(cyanomethyl)phenol, undergo cycloisomerization in situ catalyzed by Pd(PCy3)2 as a co-catalyst to give 3-acyl-2-aminobenzofurans. Palladium species with homoleptic tertiary phosphines, such as Pd(PPh3)4 and Pd(PCy3)2, can catalyze the mechanistically distinct reactions in an orthogonal-tandem manner without interference. By switching the base used in this reaction, 3-acyl-2-(N-acylamino)benzofurans were obtained as major products instead of 3-acyl-2-aminobenzofurans. Given that 2-(cyanomethyl)phenols can be synthesized from commercially available salicylic acid derivatives in two steps, the present method thus provides facile access to synthetically useful 3-acyl-2-aminobenzofurans.
AB - Three-component coupling reactions of 2-(cyanomethyl)phenol, aryl halides, and carbon monoxide (CO) in orthogonal-tandem catalysis were investigated. In the reactions, 2-(cyanomethyl)phenyl esters, which are produced through Pd(PPh3)4-catalyzed alkoxycarbonylation of aryl halides with 2-(cyanomethyl)phenol, undergo cycloisomerization in situ catalyzed by Pd(PCy3)2 as a co-catalyst to give 3-acyl-2-aminobenzofurans. Palladium species with homoleptic tertiary phosphines, such as Pd(PPh3)4 and Pd(PCy3)2, can catalyze the mechanistically distinct reactions in an orthogonal-tandem manner without interference. By switching the base used in this reaction, 3-acyl-2-(N-acylamino)benzofurans were obtained as major products instead of 3-acyl-2-aminobenzofurans. Given that 2-(cyanomethyl)phenols can be synthesized from commercially available salicylic acid derivatives in two steps, the present method thus provides facile access to synthetically useful 3-acyl-2-aminobenzofurans.
KW - 3-Acyl-2-aminobenzofuran
KW - Carbonylation
KW - Cycloisomerization
KW - Tandem catalysis
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U2 - 10.1016/j.tet.2015.04.049
DO - 10.1016/j.tet.2015.04.049
M3 - Article
AN - SCOPUS:84930224994
SN - 0040-4020
VL - 71
SP - 4432
EP - 4437
JO - Tetrahedron
JF - Tetrahedron
IS - 26-27
ER -