Aqueous base induced selective transformations of 3-(2-oxoalkyl) thiazolium cations
摘要:
The title compounds react with aqueous sodium hydroxide (i) 2%, 1 equiv., (ii) 2%, 2 equiv., and (iii) 8%, 2 equiv., to give 2-hydroxy-2-alkyl/aryl-4-formyl-2, 3-dihydro- 1, 4-thiazines (7), 2-alkyl/aryl-4-formyl-1, 4-thiazines (8) and 2-aroylthiazoles (9), respectively. 7 and 8 with 8% aqueous sodium hydroxide form 9, but 7 with 2% aqueous sodium hydroxide or TFA give 8.
Direct C-2 Acylation of Thiazoles with Aldehydes via Metal- and Solvent-Free C–H Activation in the Presence of tert-Butyl Hydroperoxide
作者:Bhalchandra Bhanage、Ashok Khemnar
DOI:10.1055/s-0033-1340068
日期:——
activation of aldehydes and thiazoles is developed. The reaction occurs smoothly, under metal-, acid- and solvent-free conditions usingtert-butylhydroperoxide as the oxidant under an air atmosphere, to afford a wide range of heteroaryl ketones in moderate to good yields. The sp2 C–H bonds in the aldehyde and thiazole undergo directoxidativecross-coupling, resulting in C-2 acylation of the azole