Maddeboina Krishnaiah

Iodine-catalyzed efficient hydrophosphonylation of N-tosyl aldimines.

Treatment of N-tosyl aldimines with dialkyl trimethylsilyl phosphites at 0 degrees C in the presence of iodine as a catalyst afforded the corresponding sulfonamide phosphonates in excellent yields within 1.5 to 2.5 h.

Benzylation and Allylation of Naphthols Using Amberlyst-15

Abstract A simple and efficient method has been developed for benzylation and allylation of naphthols by treatment of the compounds with benzylic and allylic alcohols, respectively, in the presence of amberlyst-15. Several heterogeneous catalysts were screened for the reaction, and amberlyst-15 was found to be most effective.

Efficient Synthesis of β-Hydroxy Sulfides and β-Hydroxy Sulfoxides Catalyzed by Cu/MgO Under Solvent-Free Conditions

Regio-, stereo-, and chemoselective ring opening of epoxides with thiols using Cu/MgO as a heterogeneous catalyst has efficiently been carried out to produce the corresponding β-hydroxy sulfides in excellent yields at room temperature under solvent-free conditions. The treatment of the epoxides with thiols and 50% aqueous H2O2 in the presence of the same catalyst at room temperature affords the β-hydroxy sulfoxides in excellent yields.

Tungstophosphoric Acid–Catalyzed Imino-Diels–Alder Reaction: An Efficient One-Pot Synthesis of Pyrano- and Furanoquinoline Derivatives

Abstract Tungstophosphoric acid has been found to be an efficient catalyst for the synthesis of pyranos- and furanoquinolines through the Imino-Diels–Alder reaction involving one-pot coupling of benzaldehydes, anilines, and 3,4-dihydro-2 H-pyran or 2,3-dihydrofuran. The products are formed at room temperature in excellent yields in a short period of time.

Zirconium tetrachloride catalysed synthesis of symmetric and unsymmetric ethers from secondary benzylic alcohols

Secondary benzylic alcohols are coupled in the presence of zirconium tetrachloride to afford the corresponding symmetrical ethers in good yields. Unsymmetric ethers are obtained with good selectivity by condensation of two different secondary benzylic alcohols under the action of the same catalyst.

Zirconium tetrachloride mediated regioselective transformation of N-tosylaziridines into β -chlorosulfonamides

Regioselective ring opening of N-tosylaziridines has efficiently been carried out with ZrCl4 at room temperature to afford the corresponding β-chlorosulfonamides in high yields within a short reaction time.