A New Method for Addition of Aldehydes to Activated Double Bonds

Abstract

Compound (6) (0.01 mol, n = 5) is dissolved in I N sodium hydroxide solution (30 ml), a layer of chloroform is placed under the clear solution, and (2), RZ=benzyl, R3=isopropyl(O.02 mol), is added. The mixture is well shaken and neutralized with 2N sulfuric acid. The chloroform layer is separated, dried, and evaporated in a vacuum. The residue is purified over silica gel (Merck, 0.05-0.2 mm; light petroleum/ethyl acetate 10: 1).Working up may be by pouring into water and extraction with chloroform.

Synthesis and characterization of novel substituted pyrrole, thiophene and furans

“…20,21 The most versatile general 1,4-dicarbonyl synthesis is known as the Stetter reaction, 42,43 which is the catalyzed conjugate addition of an aldehyde to a Michael acceptor such as an enone. Thiazolium salt, 44 cyanide ion, 45,46 and tributylphosphine 47 are used as the catalyst in the presence of a base. The effectiveness of the procedure depends significantly upon the choice of the catalysts.…”

A mild approach to the synthesis of 1,2-diferrocenylethanedione from ferrocenealdehyde

“…Notably, NHC mediated benzoin type condensation reaction of ferrocenealdehyde is not reported yet [2e6,22]. However, we believed that the good stereocontrol could arise from the tröger base through H-bonding interactions, as has been seen previously in benzoin condensation reaction catalyzed by functionalized chiral NHC through Breslow intermediate [36]. As shown in Table 1, initially, the benzoin condensation reaction of ferrocenealdehyde was carried out using 6 mol % of catalysts 4 in conjunction with finely ground KOtBu under nitrogen atmosphere at RT with THF as solvent.…”

New Stetter reactions catalyzed by thiamine diphosphate dependent MenD from E. coli

“…The Stetter reaction is the transformation of aromatic aldehydes (donor substrates) with ␣,␤-unsaturated carbonyl compounds (Michael acceptor substrates) in the presence of cyanide ions, which results in the formation of 1,4-addition products (Stetter and Schreckenberg, 1973). The reaction scope was vastly improved with the application of thiazolium salts as catalysts (Stetter, 1976).…”