S. Kathiravan

Rhodium(III)-catalysed aerobic synthesis of highly functionalized indoles from N-arylurea under mild conditions through C–H activation

A Rh(III) catalysed amino arylation of alkynes using copper as the terminal oxidant for regeneration of the catalytically active species under aerobic conditions is described. This novel C-H activation reaction was applied to the synthesis of a wide range of substituted indoles from N-arylureas.

Palladium Catalyzed Vinyltrifluoromethylation of Aryl Halides through Decarboxylative Cross-Coupling with 2-(Trifluoromethyl)acrylic Acid

An efficient Pd-catalyzed stereoselective vinyltrifluoromethylation of aryl halides, through decarboxylative cross-coupling with 2-(trifluoromethyl)acrylic acid is described. The ready availability of the starting materials, the high level of functional group tolerance, and excellent E/Z selectivity make this protocol a safe and operationally convenient strategy for efficient synthesis of vinyltrifluoromethyl derivatives.

Cobalt Catalyzed, Regioselective C(sp2)–H Activation of Amides with 1,3-Diynes

The development of a first row transition metal (cobalt)-based catalyst for the as yet unexplored C-H activation-driven reaction of 1,3-diynes, themselves a functional class of interest in a range of application areas, to form isoquinolinones-an important structural motif in a number of biologically active substances-is presented. This versatile and inexpensive catalyst employs a covalently attached bidendate-directing group, 8-aminoquinoline. The template directs the C-H activation and facilitates the synthesis of a wide range of alkynylated heterocycles under mild conditions and with excellent regioselectivity. This strategy provides a novel and efficient route to diverse heterocyclic frameworks as demonstrated by its late stage application in bisheterocycle syntheses.

Monoprotected l-Amino Acid (l-MPAA), Accelerated Bromination, Chlorination, and Iodination of C(sp2)-H Bonds by Iridium(III) Catalysis

Halogenated arenes are important structural motifs commonly found in biologically active molecules and used for a variety of transformations in organic synthesis. Herein, we report the mono-protected l-amino acid (l-MPAA) accelerated iridium(III)-catalyzed halogenation of (hetero)anilides at room temperature. This reaction constitutes the first example of an iridium(III)/l-MPAA-catalyzed general halogenation of (hetero)arenes through C(sp2 )-H activation. Furthermore, we demonstrate the potential utility of our method through its use in the synthesis of a quinolone derivative.

Methyl 5-ferrocenyl-5a-hydr­oxy-1-methyl-10-oxo-2,3,3a,4,5a,10-hexa­hydro-1H-indeno[1,2:2′,3′]furo[3′,4′-b]pyrrole-3a-carboxyl­ate

In the title compound, [Fe(C5H5)(C21H20NO5)], the pyrrolidine and cyclopentanone rings exhibit a twist conformation. The pyrrolidine ring is almost perpendicular to the cyclopentanone ring, making a dihedral angle of 81.91 (6)°. The molecular conformation is stabilized by an intramolecular O—H⋯N hydrogen bond and C—H⋯O interactions. The crystal structure is stabilized by intermolecular C—H⋯O interactions.

Synthesis of Pyrrolo[2,3-a]pyrrolizidino Derivatives Through Intramolecular 1,3-Dipolar Cycloaddition in Ionic Liquid Medium

Abstract An ecofriently method for the synthesis of pyrrole-fused polycyclic heterocycles through intramolecular 1,3-dipolar cycloaddition reaction of azomethine ylides derived from pyrrole-2-carbaldehyde and secondary amino acids in ionic liquid [bmim][BF4] as green solvent is reported. GRAPHICAL ABSTRACT

Synthesis of Naphtho[2,1-b]pyrano Pyrrolothiazole Derivatives through 1,3-Cycloaddition Reaction

Abstract Facile synthesis of a series of naphtho[2,1,b]pyrano pyrrolo thiazoles was accomplished in good yields in a one-pot reaction through intramolecular 1,3-dipolar cycloaddition of cyclic azomethine ylides with Baylis–Hillman adducts as dipolarophiles. The protocol is applicable to a wide variety of photochromic and biologically active napthopyrano products. The regio- and stereochemical outcome of the cycloaddition reaction was ascertained by x-ray crystallographic study of one of the cycloadducts. GRAPHICAL ABSTRACT

Synthesis and antimicrobial activities of novel ferrocenyl dispiropyrrolidines and pyrrolizidines

A series of novel ferrocenyl spiropyrolidines and pyrrolizidines have been synthesized through 1,3-dipolar cycloaddition reaction of azomethine ylide generated from amino acids and various 1,2-diketones with ferrocenyl Baylis–Hillman adducts as dipolarophiles. The synthesized cycloadducts were evaluated for antimicrobial activities. Compounds 12, 13, 14, and 18 showed relatively good antimicrobial activity.

19-Ferrocenyl-18-oxa-8,16-diaza­penta­cyclo­[8.6.3.01,10.02,7.012,16]nona­deca-2(7),3,5-triene-9,17-dione

In the title compound, [Fe(C5H5)(C21H19N2O3)], both pyrrolidine rings of the pyrrolizine substructure show an envelope conformation. In the ferrocenyl moiety, the unsubstituted cyclopentadienyl ring is disordered over two orientations with site occupancies of 0.64 (2) and 0.36 (2). In the pyrrolizine ring, one C atom is disordered over two positions, with site occupancies of 0.71 (1) and 0.29 (1). Intramolecular C—H⋯O interactions occur. The crystal packing is established through weak intermolecular C—H⋯O and N—H⋯O interactions.

Methyl 4-phenyl-1,2,3,3a,4,4a,5,12c-octa-hydronaphtho[1',2':3,2]furo[5,4-b]pyrrolizine-4a-carboxyl-ate.

In the title compound, C26H25NO3, both pyrrolidine rings adopt envelope conformations, whereas the dihydropyran ring adopts a half-chair conformation. The phenyl ring is oriented at an angle of 27.9 (1)° with respect to the naphthalene ring system. An intramolecular C—H⋯O hydrogen bond is observed. The crystal packing is stabilized by weak intermolecular C—H⋯π interactions.