An ecofriendly approach to the synthesis of 2-imino- and 2-oxo-3-phenylsulfonyl-2H-chromenes
作者:Tatiana A. Dias、M. Fernanda Proença
DOI:10.1016/j.tetlet.2012.07.069
日期:2012.9
An efficient synthesis for 2-imino-3-phenylsulfonyl-2H-chromenes was developed from the Knoevenagel condensation of (phenylsulfonyl)acetonitrile and salicylaldehydes in aqueous sodium carbonate solution, at room temperature. Hydrolysis in aqueous HCl, at 80 degrees C, led to the formation of the corresponding 2-oxo-3-phenylsulfonyl-2H-chromenes, also isolated in excellent yields. (c) 2012 Elsevier Ltd. All rights reserved.
Organocatalytic Cascade Knoevenagel–Michael Addition Reactions: Direct Synthesis of Polysubstituted 2-Amino-4H-Chromene Derivatives
作者:Sanjay N. Jadhav、Seema P. Patil、Dipti Prava Sahoo、Dharitri Rath、Kulamani Parida、Chandrashekhar V. Rode
DOI:10.1007/s10562-019-03089-8
日期:2020.8
isotherms measurements, and they were successfully examined for the cascade type Knoevenagel–Michael addition reactions. The product yields associated with these substrates were optimized, and key reaction parameters affecting the yields were identified. The present catalytic method is simple and robust for diversity oriented synthesis which proceeds good to excellent yields without generating any hazards