One-pot sequential combination of multi-component and multi-catalyst: synthesis of 5-aminobenzofurans from aminophenol and ketene acetals
摘要:
The reaction between p-aminophenols 1 and various ketene acetals 2 in the presence of hypervalent iodine is described. The results show that 2- and 3-substituted 5-sulfonamidobenzofurans 3 are obtained in moderate to good yields from p-aminophenols and ketene acetals. (C) 2012 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Formal Carbene Migratory Insertion into Internal Olefinic C═C Bonds with <i>N</i>-Tosylhydrazones To Access Iminofuran and 2(3<i>H</i>)-Furanone Derivatives
α-oxo ketene N,S-acetals, has been achieved by means of N-tosylhydrazones of ketones as the carbene precursors. Iminofuran derivatives were obtained and further transformed to the corresponding 2(3H)-furanones and 4-oxobutanoates (γ-ketoesters), respectively, under mild conditions. In a similar fashion, α-thioxo ketene N,S-acetals reacted with N-tosylhydrazones of ketones to afford iminothiophenes. It
S-acetals) under mild conditions. Simple treatment of such enaminones with PhI(OAc)2 at ambient temperature in air afforded diverse multiply functionalized α,β-unsaturatedamides including β-cyclopropylated acrylamides, in which a wide array of functional groups such as aryl, (hetero)aryl, alkenyl, and alkyl can be conveniently introduced to a ketene moiety. The reaction mechanism was investigated by exploring
The reaction between p-aminophenols 1 and various ketene acetals 2 in the presence of hypervalent iodine is described. The results show that 2- and 3-substituted 5-sulfonamidobenzofurans 3 are obtained in moderate to good yields from p-aminophenols and ketene acetals. (C) 2012 Elsevier Ltd. All rights reserved.