47 research outputs found
Synthesis of benzopyranopyrrolidines via 1,3-dipolar cycloaddition of nonstabilized azomethine ylides with 3-substituted coumarins
Diastereoselective Synthesis of Phosphines and Phosphoranes using Fluorinated Acetylacetones
Nucleophilic properties of a nonstabilized azomethine ylide derived from sarcosine and cyclohexanone. A novel domino reaction leading to substituted 4-aryl-2-pyrrolidones
A nonstabilized asymmetric azomethine ylide derived from sarcosine and cyclohexanone reacts with 3-substituted coumarins and ethyl benzylidene malonate to give 4-aryl-2-pyrrolidones in moderate yields, and the adducts of classical 1,3-dipolar cycloadditions as the minor products. The main reaction proceeds via a domino process, starting with 1,4-nucleophilic addition to the conjugated double bond, and represents the first example of the nucleophilic properties of a nonstabilized azomethine ylide. © 2012 Published by Elsevier Ltd
Effects of Structure on the Free Radical Reactions of Hydridophosphoranes with Dimethyl Sulfide
1,3-Dipolar cycloadditions of nonstabilised azomethine ylides at 3-substituted coumarins: Synthesis of 1-benzopyrano[3,4-c]pyrrolidines
Reaction of 3-substituted coumarins with N-alkyl-α-amino acids and aldehydes proceeds regio- and stereoselectively to give 1-benzopyrano[3,4-c] pyrrolidines as a result of 1,3-dipolar cycloaddition of the intermediate azomethine ylides at the Δ 3-bond of the coumarins. © 2012 Mendeleev Communications. All rights reserved
2-Cyano-6-(trifluoromethyl)-4H-pyran-4-one: A novel versatile CF 3-containing building block
A highly electrophilic pyrone, 2-cyano-6-(trifluoromethyl)-4H-pyran-4-one, was synthesized. The reactions of this cyanopyrone with N-nucleophiles can proceed with or without substitution of the cyano group to give a wide range of novel trifluoromethylated compounds. An oxindole derivative was synthesized from a phenylhydrazide using unusual (acidic) conditions. © 2012 Elsevier B.V