Phosphine-catalyzed [4 + 2] annulation and vinylogous Michael addition reactions between 1,4-dien-3-ones and 1,1-dicyanoalkenes are presented. Under the catalysis of PBu(3) (20 mol %), 1,4-dien-3-ones like styryl ketones with 2-aryl 1,1-dicyanoalkenes as doubly activated alkenes readily undergo a formal [4 + 2] cycloaddition reaction, affording polysubstituted cyclohexanones in satisfactory yie...

An optimisation of Michael-type addition of azole derivatives of broad-scale acidity - ranging from 5.20 to 15.00 pK(a) units - namely 4-nitropyrazole, 3,5-dimethyl-4-nitropyrazole, 4(5)-nitroimidazole, 4,5-diphenylimidazole, 4,5-dicyanoimidazole, 2-methyl-4(5)-nitroimidazole, 5(4)-bromo-2-methyl-4(5)-nitroimidazole and 3-nitro-1,2,4-triazole to methyl acrylate as an acceptor was carried out. T...

A transition-metal-free and base-promoted one-pot reaction of ynones with 2-aminobenzonitriles is described. The was initiated through sequential aza-Michael addition/intramolecular annulation to afford various multisubstituted 4-aminoquinolines 4-amino-1,8-naphthyridines in good excellent yields. Operational simplicity, high atom-economy broad substrate scope makes this protocol more attractiv...

Mukaiyama Michael addition of silyl enol ethers 13 to the 1,2-quinone-4-carboxylate 6 (formed in situ by oxidation of the catechol ester 8) afforded the 2-subsituted 7-hydroxybenzofuran-4-carboxylates 14 in fair to good yields. Alkyl and aryl systems work well, but highly electron-rich silyl enol ethers could not be used because of competing oxidation.

Enantioselective organocatalytic Michael addition reactions of 1-acetylcyclohexene, 1-acetylcyclopentene and 1-acetylcyclobutene to nitroolefins have been developed. This is the first report where an α-branched enone has been activated by an amine catalyst for the asymmetric Michael addition reaction to an electrophile. The Michael products have also been cyclized to bicyclic compounds.