Search results for "tandem reaction"
showing 4 items of 4 documents
New approach to condensed pyrid-2-ones
2002
We wish to report a simple procedure for the preparation of 5-substituted-thienopyridin-7-ones and 7-substituted-1,6-naphthyridin-5(6H)-ones, in good yields, from the dianions of 3-methylthiophene-2-carboxylic and 2-methylnicotinic acids on treatment with nitriles. Brun Sanchez, Eva Maria, Eva.M.Brun@uv.es ; Gil Grau, Salvador, Salvador.Gil@uv.es ; Parra Alvarez, Margarita, Margarita.Parra@uv.es
Synthesis of 4(5)-phenacyl-imidazoles from isoxazole side-chain rearrangements
2010
A novel base-induced rearrangement of isoxazoles into imidazole derivatives is reported. In the isoxazole series, this represents the first example of a three-atom side-chain rearrangement involving a CNC sequence. The reactions are carried out under nitrogen and produced 2-aryl-4(5)-phenacyl-5(4)-phenyl-imidazoles in high yields. In the presence of oxygen, a cascade rearrangement-oxidation reaction sequence was observed and imidazole derivatives bearing an oxidized side-chain were isolated.
Tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR). An easy entry to linear bicyclic scaffolds
2015
A new tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR) has been carried out. It involves conjugated ketones, esters or amides bearing a remote olefin and aromatic alkynes as the starting materials. The overall process enables the preparation of a small family of linear bicyclic scaffolds in a very simple manner with moderate to good levels of diastereoselectivity. This methodology constitutes one of the few examples that employ olefins differently than ethylene in tandem CEYM–IMDAR protocols.
Asymmetric tandem reactions: New synthetic strategies
2010
The use of domino and multicomponent reactions in asymmetric synthesis is constantly increasing nowadays. This allows for the synthesis of complex molecules in a single synthetic sequence, usually with high atom economy. Herein, we report three examples of new asymmetric tandem reactions recently developed in our laboratories, giving rise to new families of enantiomerically enriched fluorinated and nonfluorinated heterocycles. Thus, 1,4-dihydropyridines (1,4-DHPs) bearing fluorinated substituents at C6 were assembled by means of a Hantzsch-type reaction; cyclic β-amino carbonyl derivatives were prepared using a cross-metathesis (CM)–intramolecular aza-Michael sequence; while fluorinated ind…