1,721,032 research outputs found
The Vilsmeier-Haack Reaction with 3,4-Disubstituted Isossazolin-5-ones. A New Synthesis of 1,3-Oxazin-6-Ones and 1,3-Oxazine-2,6-Diones
The Vilsmeier-Haack Reaction with 3,4-Disubstituted Isossazolin-5-ones. A New Synthesis of 1,3-Oxazin-6-Ones and 1,3-Oxazine-2,6-Dione
Pd-Catalyzed Intramolecular Cyclization of Pyrrolo-2-carboxamides: Regiodivergent Routes to Pyrrolo-pyrazines and Pyrrolo-pyridines
Diastereoselective synthesis of enantiopure (alpha R)-2-methyl-4-(alpha-phenylethyl)-1,2,3,4-tetrahydro-benzo[e][1,4]diazepin-5-ones
Biodiversità bancaria e criterio di proporzionalità alla prova della riforma del credito cooperativo: prime riflessioni
Palladium-mediated Approach to Dibenzo[b,e][1,4]diazepines and Benzopyrido-analogues. An Efficient Synthesis of Tarpane
Efficient palladium-catalyzed direct arylation of azines and diazines using ligand-free conditions
Palladium-Catalyzed dual C-H or N-H functionalization of unfunctionalized indole derivatives with alkenes and arenes
Novel Intramolecular Cyclization of N-Alkynyl Heterocycles Containing Proximate Nucleophiles
Intramolecular Cyclization of delta-Iminoacetylenes: A New Entry to Pyrazino[1,2-a]indoles
The synthesis of the pyrazino[1,2-α]indole nucleus was achieved by intramolecular cyclization of several 2-carbonyl-1-propargylindoles in the presence of ammonia. The reaction conditions were optimized using microwave heating and a pool of catalysts. Cyclization of 1-alkynylindole-2-carbaldehydes was easily accomplished under standard heating conditions, whereas microwave heating contributed to reduced reaction times and improved overall yields. Moreover, a fine-tuning of the microwave irradiation time made possible the selective synthesis of both pyrazino[1,2-α]indole isomers. TiCl4 proved the catalytic system of choice to achieve pyrazinoindoles in satisfactory yields starting from 1-alkynyl-2-acetylindoles and 1-alkynyl-2-benzoylindole derivatives. Also in these cases, microwave heating contributed to faster reactions and improved yields. The uncatalyzed versus catalyzed reaction mechanism is discussed
- …
