ABSTRACT
The stereoselective syntheses of a library of novel spiro-tethered pyrazolo[3,4-b]quinoline-pyrrolidine/pyrrolothiazole/indolizine-oxindole/acenaphthene hybrid heterocycles have been achieved through the 1,3-dipolar cycloaddition of azomethine ylides generated in situ from α-amino acids and 1,2-diketones to dipolarophiles derived from pyrazolo[3,4-b]quinoline derivatives.
Subject(s)
Combinatorial Chemistry Techniques/methods , Cycloaddition Reaction/methods , Heterocyclic Compounds/chemical synthesis , Quinolines/chemical synthesis , Azo Compounds , Small Molecule Libraries/chemical synthesis , Spiro Compounds , Stereoisomerism , ThiosemicarbazonesABSTRACT
A facile and efficient synthesis of a library of novel chromeno[3,2-c]pyridines has been achieved from the reaction of various 3,5-((E)-arylidene)-1-alkylpiperidin-4-ones and cyclic 1,3-diketones. The reaction presumably occurred via tandem Michael addition-intramolecular O-cyclization-elimination sequence in a single operation.
Subject(s)
Pyridines/chemistry , Cyclization , Molecular Structure , Pyridines/chemical synthesisABSTRACT
The present investigation reports an easy access to a library of novel spiro-oxindole-pyrrolizine or pyrrolo[1,2-c]thiazole fused coumarin hybrid heterocycles through a one-pot sequential four-component reactions of 2,2-dimethyl-1,3-dioxane-4,6-dione, salicylaldehydes, isatins, and cyclic α-amino acids under ultrasound irradiation.
