K. Rama Rao

Indium-Catalyzed C−S Cross-Coupling of Aryl Halides with Thiols

Indium-catalyzed C-S cross-coupling of aromatic and alkane thiols with aryl halides proceeds smoothly in the presence of In(OTf)(3) (10 mol %), TMEDA (20 mol %), and KOH as a base in DMSO at 135 degrees C. When this protocol was utilized, a variety of thiols could be cross-coupled with aryl halides to afford the corresponding aryl sulfides in good to excellent yields.

Recyclable Heterogeneous Iron Catalyst for C-N Cross-coupling under Ligand-free Conditions

An efficient and ligand-free C-N cross-coupling of aryl halides with various heterocycles using Fe/C(g) as a recyclable catalyst is reported. The yields are excellent to moderate.

Supramolecular Synthesis of 3-Indolyl-3-hydroxy Oxindoles under Neutral Conditions in Water

Various 3-indolyl-3-hydroxy oxindoles were prepared for the first time by supramolecular catalysis involving the reaction of beta-CD:isatin complexes with indoles under neutral conditions in water. beta-Cyclodextrin can be recovered and reused a number of times without loss of activity.

Study of the Michael addition of β-cyclodextrin–thiol complexes to conjugated alkenes in water

An environmentally benign and highly efficient supramolecular Michael addition of thiols from the secondary side of beta-cyclodextrin to alpha,beta-unsaturated compounds at the primary side in water is described in quantitative yields; products of undesirable side reactions resulting from polymerization are not observed; the use of cyclodextrin precludes the use of either acid or base and the catalyst can be recovered and reused.

Highly facile biomimetic regioselective ring opening of epoxides to halohydrins in the presence of β-cyclodextrin

Abstract Highly regioselective ring opening of epoxides to halohydrins has been carried out in impressive yields with hydrogen and lithium halides in presence of β-cyclodextrin using water as solvent.

Unexpected C−Se Cross-Coupling Reaction: Copper Oxide Catalyzed Synthesis of Symmetrical Diaryl Selenides via Cascade Reaction of Selenourea with Aryl Halides/Boronic Acids

Selenourea is used as an effective selenium surrogate in the C-Se cross-coupling reaction catalyzed by copper oxide nanoparticles under ligand free conditions. This protocol has been utilized for the synthesis of a variety of symmetrical diaryl selenides in good to excellent yields from the readily available aryl halides/boronic acids.

Baker's yeast catalyzed asymmetric cycloaddition of nitrileoxides to CC bond : Improved chiral recognition by using β-cyclodextrin☆

Bakers yeast catalyzes for the first time the asymmetric cycloaddition reaction of arylsubstituted nitrileoxides 1 to vinylpyridines 2 to yield optically active 2-isoxazolines 3. The stereoselectivity is enhanced by fixing the geometry of both dipole and dipolarophile by using β-cyclodextrin as an additional binding cavity along with Bakers yeast.

A regioselective enzyme catalyzed cycloaddition

Abstract Bakers Yeast catalyzed the regioselective cycloaddition of nitrileoxides 1 to cinnamic esters 2 . Reversal of regioselectivity is observed in these cycloadditions by using β-cyclodextrin as an artificial enzyme along with bakers Yeast.

A stereoselective biocatalytic diels-alder reaction

Abstract Bakers yeast catalyzes the stereoselective Diels-Alder reaction of cyclopentadiene 1 with dienophiles 2 , 4 and 6 . A predominant formation of exo isomer is observed in some cases.

A mild and efficient biomimetic synthesis of α-hydroxymethylarylketones from oxiranes in the presence of β-cyclodextrin and NBS in water

Abstract α-Hydroxymethylarylketones can be synthesized in good yields from easily accessible epoxides in the presence of β-cyclodextrin and NBS in water. This method is a direct, one-pot, synthesis under mild conditions using water as solvent and has many advantages over existing methodologies.