M. Poornachandran

Synthesis of Spirooxindolo/Spiroindano Nitro Pyrrolizidines through Regioselective Azomethine Ylide Cycloaddition Reaction

Abstract Synthesis of a series of spirooxindolonitro pyrrolizidines and spiroindanonitro pyrrolizidines has been accomplished. The nonstabilized azomethine ylides generated from isatin and ninhydrin with proline reacted with nitro styrenes to regioselectively yield spirocycloadducts.

Regioselective Synthesis of Novel Spirooxindolo and Spiroindano Nitro Pyrrolidines Through 3+2 Cycloaddition Reaction

Abstract β‐Nitro styrene reacts with nonstabilized azomethine ylides generated from isatin/ninhydrin with sarcosine, resulting in the formation of a series of spiroxindolo nitro pyrrolidines, and spiroindano nitro pyrrolidines, respectively, in good yields. It was noted that in a one‐pot 3+2 cycloaddition reaction, the azomethine ylides generated from isatin and ninhydrin have reacted with the β‐nitro styrenes regiochemically in opposite ways.

Regioselective Synthesis of Dispirocycloalkanooxindolopyrrolidines and Dispirocyclalkanoindanopyrrolidines

Synthesis of a series of novel dispirocycloalkanone-oxindolopyrrolidines and dispirocycloalkanone-indanopyrrolidines is described. The nonstabilized azomethine ylides generated from a secondary amino acid, sarcosine, and carbonyl components (isatin and ninhydrin) have been effectively trapped by the dipolarophiles, arylidene cycloalkanones, to afford dispiropyrrolidines. The one-pot azomethine ylide cycloaddition reactions were highly regioselective.

Facile Synthesis of cis-Fused 1-Benzyl/-H-5-arylsulfonyl Pyrrolo[3,4-b]pyrroles

Abstract Synthesis of novel 1-H-pyrrolo[3,4-b]pyrrole derivatives with high stereoselectivity has been accomplished through intramolecular trapping of an azomethine ylide generated by the reaction of N-tethered alkenyl aldehyde with α-amino acids.

(3aR,6S,6aR)-6-Benzyl-1-(4-bromophenyl)-5-tosyl-cis-perhydropyrrolo[3,4-b]pyrrole

The title compound, C26H27BrN2O2S, has two fused pyrrolidine rings, each in a twist conformation.

Regioselective synthesis of rac -(1R,4R,6 R ,6a R )-6′-phenyl-7′,8′-dihydro-1″ H ,2′ H ,6′ H -dispiro[cycloalkane-1,5′-pyrrolo[1,2- c ][1,3]thiazole-4′,3″-indole]-2,2″-diones through 3 + 2 cycloaddition reaction

Synthesis of a series of novel rac-(1R,4R,6R,6aR)-6′-phenyl-7′,8′-dihydro-1″H,2′H,6′H-dispiro[cycloalkane-1,5′-pyrrolo[1,2-c][1,3]thiazole-4′,3″-indole]-2,2″-diones by cycloaddition reaction is described. The nonstabilised azomethine ylide generated by the reaction of isatin and thiazolidine-2-carboxylic acid has been regioselectively trapped by various substituted benzylidene cycloalkanones.

3-(4-Methoxy­phen­yl)-6-(phenyl­sulfon­yl)perhydro-1,3-thiazolo[3′,4′:1,2]pyrrolo[4,5-c]pyrrole

In the title compound, C21H24N2O3S2, the three five-membered rings adopt envelope conformations. The dihedral angle between the two aromatic rings is 68.4 (1)°. C—H⋯O interactions link the molecules into a chain and the chains are cross-linked via C—H⋯π interactions involving the methoxyphenyl ring.

1'-Phenyl-6'-thia-cyclo-heptane-1-spiro-2'-perhydro-pyrrolizine-3'-spiro-3''-indoline-2,2''-dione.

The thiazolidine ring and the pyrrolidine ring in the title compound, C25H26N2O2S, both adopt an envelope conformation. The seven-membered ring has a twist-chair conformation. The crystal packing is stabilized by intermolecular N—H⋯O hydrogen bonds.