Ch. Narsihmulu

Three component coupling catalyzed by TaCl5–SiO2: synthesis of α-amino phosphonates ☆

Abstract TaCl5–SiO2 has been utilized as an efficient Lewis acid catalyst for the three component coupling of carbonyl compounds, aromatic amines and diethyl phosphite to produce α-amino phosphonates.

Osmium tetroxide in poly(ethylene glycol) (PEG): a recyclable reaction medium for rapid asymmetric dihydroxylation under Sharpless conditionsDedicated to Prof. Goverdhan Mehta on his 60th birthday.Electronic supplementary information (ESI) available: experimental details. See http://www.rsc.org/suppdata/cc/b3/b305154b/

PEG (400) has been used as a recyclable and rapid reaction medium for the asymmetric dihydroxylation of olefins; Sharpless ligand is efficiently recovered and recycled with good enantioselectivity.

Ceric ammonium nitrate (CAN) catalyzed ring cleavage of N-tosyl aziridines: a potential tool for solution phase library generation

Abstract A range of N-tosylaziridines is cleaved with NaN3, H2O, MeOH to synthesize vicinal azidoamines, aminols and amino ethers in good to excellent yields catalyzed by ceric ammonium nitrate and used in solution phase library synthesis.

Triethylborane triggered intermolecular domino Michael–aldol three-component coupling reactions☆

Abstract The triethylborane triggered intermolecular domino Michael–aldol reaction is described. Initial triethylborane addition in a Michael fashion to methyl vinyl ketone resulted in a vinylborane which further reacted with an aldehyde to give the aldol product in a one-pot process.

Direct conversion of azides to carbamates and sulfonamides using Fe/NH4Cl: effect of sonication ☆

Abstract A simple, direct and effective conversion of azides to carbamates and sulfonamides is achieved using Fe/NH 4 Cl in methanol. The influence of sonication and direct application in solution phase combinatorial chemistry are also studied by developing a 6×4 matrix library.

Direct condensation of carboxylic acids with polyethylene glycols catalyzed by Sc(OTf)3

Abstract Esterification of soluble polymers by direct condensation of equimolar amounts of carboxylic acids with polyethylene glycols is achieved using catalytic Sc(OTf)3 in toluene for the first time.