Saibal Kumar Das

A mild and convenient indium(III) chloride-catalyzed synthesis of thioglycosides

The efficiency of glycosidation reactions generally involves a high chemical yield, as well as high/complete stereo- and regioselectivity. All these depend on the compatibility of the reactivity of glycosyl donors and acceptors. Among glycosyl donors, thioglycosides are widely used because of their high degree of stability in many organic reactions. Although there are number of methods available for the preparation of thioglycosides, all of them have one or more disadvantages, especially concerning the time factor and cumbersome workup procedures. Here we report a convenient and high-yielding method for the preparation of thioglycosides.

Microwave-induced, InCl3-catalyzed ferrier rearrangement of acetylglycals: synthesis of 2,3-unsaturated C-glycosides

Abstract Indium(III) chloride-catalyzed, microwave-assisted Ferrier rearrangement of different per-O-acetylglycals leads to an efficient synthesis of 2,3-unsaturated C-glycosides in good to excellent yields.

Endothelin receptor antagonists: an overview of their synthesis and structure-activity relationship.

Endothelins (ETs) are potent vasoconstrictor peptides and are associated with several disease states like pulmonary hypertension, systemic hypertension and heart failure. Endothelin-1 (ET-1) is the first member of the family and it has the receptor subtypes known as ETA and ETB. The receptors ETA and ETB are attractive new therapeutic targets for diseases associated with elevated ET-1 levels. Several studies have thus led to the discovery of selective ETA receptor antagonists as well as non-selective ETA/ETB antagonists. The preclinical and clinical studies have clearly established that these antagonists are effective in the treatment of essential hypertension, pulmonary hypertension, heart failure and atherosclerosis. The advances in this area have resulted in the FDA approval of the orally active dual antagonist Bosentan for pulmonary hypertension in 2001. This review highlights the synthesis and structure-activity of the endothelin receptor antagonists and covers the literature in this area up to 2001.

Microwave‐Induced Rapid Access to Aromatic and Heteroaromatic Sulfonamides Under Solvent‐Free Conditions Without Using External Base

Abstract Microwave‐induced syntheses of sulfonamides, without using base under solvent‐free conditions, have been developed. The process finds its utility because of its simple operational procedure and high yields. Moreover, the process is fast and accommodative to different substituents on aromatic as well as heteroaromatic rings rendering sulfonamides (28 examples). #DRL‐Publication No. 327.