First sequential Mukaiyama–Michael reaction/crossed-Claisen condensation using two molar ketene silyl acetals and one molar α,β-unsaturated esters promoted by a NaOH catalyst

Abstract

The NaOH-catalyzed first sequential Mukaiyama-Michael reaction/crossed-Claisen condensation is developed using two molar ketene silyl acetals and one molar alpha,beta-unsaturated esters in either a stepwise or one-pot manner.

Indium Tribromide Catalyzed Cross‐Claisen Condensation between Carboxylic Acids and Ketene Silyl Acetals Using Alkoxyhydrosilanes

“…between metal enolates and active acylating reagents, such as acid anhydrides or acid chlorides, have resulted in a reduction in side reactions. [3][4][5] Carboxylic acids are promising candidates as acylating reagents, but their direct use remains a challenging problem because the acidic proton often causes decomposition of the catalyst and undesired side reactions. Most of the reported reactions require the use of harsh reagents such as SOCl 2 [6] or N,N'-carbonyldiimidazole to prepare active intermediates from carboxylic acids, [7] and these reactions result in troublesome by-products being generated.…”