In the presence of trifluoromethanesulfonic acid (TfOH) or bis(trifluoromethane-sulfonyl)imide (Tf₂NH), iodosobenzene (PhI=O) efficiently promoted the reactions of dicarbonyl compounds as well as monocarbonyl compounds with nitriles to give 2,4-disubstituted and 2,4,5-trisubstituted oxazole in a single step under the mild conditions.

[reaction: see text] The cinchona alkaloids catalyze direct asymmetric Mannich reactions of cyclic 1,3-dicarbonyl compounds with acyl imines to afford alpha-quaternary carbon-bearing reaction products in yields of up to 98%, a diastereomeric excess of 90% or greater, and enantioselectivities up to 99% ee. A model is proposed that accounts for both the observed diastereoselectivities and the ena...

Ferric phosphate accelerated condensation reaction of aldehydes, 1,3-dicarbonyl compounds and amuniom acetate refluxing ethanol that remains a common theme in current literature.

Iron (III) phosphate catalyzed condensation reaction of aldehydes, 1,3-dicarbonyl compounds and amuniom acetate refluxing ethanol that remains a common theme in current literature.

In this manuscript, we describe the synthesis of the carbohydrazide 2. Acid-catalyzed condensation with several carbonyl compounds to afford the corresponding carbohydrazide derivatives 3-12. Their acetylation afforded the corresponding acetyl derivatives 13-22. Oxidative cyclization of O-acetyl derivatives 19-22 afforded the corresponding 1,3,4-oxadiazole derivatives 23-2...

A domino propargylation/furanylation (intramolecular exo-dig-cyclization)/benzannulation reaction of 2,4-diyn-1-ols with 1,3-dicarbonyl compounds has been developed for the first time. This provides a novel and effective method preparation aryl/heteroaryl-fused benzofurans from easily accessible starting materials in single step. The methodology was extended to pyrrolyl-benzannulation obtain in...

A diastereoselective and enantioselective construction of 2,3-disubstituted 1,4-dicarbonyl compounds is reported. Nishiyama's RuPhebox complex (2.0 mol% catalyst loading) serves as a chiral Lewis acid in conjunction with BrCCl3 base for the oxidative homocoupling 2-acyl imidazoles via stereocontrolled reaction intermediate Ru enolates situ brominated imidazoles. Cleavage achiral imidazole auxil...

An effective one-pot synthesis of dihydropyrimidinonoes in solvent free conditions using CuCl2 as an inexpensive and readily available reagent through Biginelli condensation reaction of aldehyde derivatives, 1,3-dicarbonyl compounds and urea is described. Excellent yields, short reaction times for formation of the products and simple work-up are attractive features of this green protocol.