Saikat Das Sharma

A highly efficient and green method for the synthesis of 3,4-dihydropyrimidin-2-ones and 1,5-benzodiazepines catalyzed by dodecyl sulfonic acid in water

A simple, efficient, mild and green method has been developed for the synthesis of 3,4-dihydropyrimidin-2-ones employing dodecyl sulfonic acid as an excellent surfactant-type Bronsted acid catalyst in aqueous media at room temperature. The catalyst was shown to be equally effective for the synthesis of 1,5-benzodiazepines under the same reaction condition.

Practical, Ecofriendly, and Chemoselective Method for the Synthesis of 2-Aryl-1-arylmethyl-1H-benzimidazoles Using Amberlite IR-120 as a Reusable Heterogeneous Catalyst in Aqueous Media

Abstract A simple, efficient, and environmentally benign method has been developed for the exclusive formation of biologically significant 2-aryl-1-arylmethyl-1H-benzimidazoles under the heterogeneous catalysis of Amberlite IR-120 in aqueous media in excellent yields. The catalyst is recyclable without loss of activity.

Efficient Synthesis of bis- and tris-Indolylalkanes Catalyzed by a Brønsted Acid–Surfactant Catalyst in Water

Abstract A simple and efficient synthesis of bis- and tris-indolylalkanes from carbonyls (aldehydes/ketones) and indoles with excellent yields in the presence of dodecylsulphonic acid (DSA) in water at room temperature is described. The catalyst is also applicable for the synthesis of 3,3-di(3-indolyl)oxindoles. The dodecylsulphonic acid acts as both Brønsted acid and surface-active agent in the reaction mixture.

SDS/Ac2O/H2O: Surfactant‐Mediated Cleavage of Imines with Acetic Anhydride to Carbonyls and Acetanilides in Water

Abstract Surfactant (SDS)‐mediated cleavage of imines was achieved with acetic anhydride to the corresponding carbonyls (aldehydes and ketones) and acetanilides in water at 25–30°C with very good to excellent yields, thus contributing significantly to the green chemistry concept.

AlCl3 · 6H2O/KI/CH3CN/H2O: An Efficient and Versatile System for Chemoselective C–O Bond Cleavage and Formation of Halides and Carbonyl Compounds from Alcohols in Hydrated Media

Abstract AlCl3 · 6H2O/KI/CH3CN/H2O, an efficient and versatile system, cleaves the C–O bonds of esters, acetals, ethers, and oxathiolanes to the corresponding acids, alcohols, and carbonyl compounds chemoselectively at 80 °C in hydrated media with good yields. This system also converts the alcohols (primary/secondary) to halides and oxidizes the alcohols (primary/secondary) to the corresponding carbonyl compounds in the presence of DMSO.

A Simple and Convenient Synthesis of Pyrazinones

Abstract Pyrazinones were synthesized by reacting mesoionic azlactone [2‐aryl‐4‐methyl‐Δ2‐oxaxolin‐5‐one] and 1,4‐diazabutadienes in good yields at room temperature.