Research Interests

CURRENT RESEARCH ACTIVITIES

Our research interests have been in three directions. The first direction aimed at developing novel Synthetic equivalents based on Weinreb’s amide (WA) functionality and their applications in synthesis of important molecules. The second direction aims at the synthesis of important and challenging targets from the realm of carbohydrate chemistry. The chosen targets belonged to the class of C-glycosides and Aza-analogues. The third direction basically aims at developing new synthetic strategies for biologically/medicinally important molecules.

The concept of “synthetic equivalents” or “building blocks” based on the Weinreb amide functionality proposed by us has come a long way. There existed no such idea until we proposed this concept and initiated a systematic pursuit during 1996-2000. Today we have to our credit several interesting and novel building blocks based on the Weinreb-amide functionality, for important applications. One of them needs a special mention as it finds place in the Aldrich Catalogue. A critical and comprehensive review on Weinreb-amide chemistry (Synthesis 2008) not only enlists our achievements in the proper perspective, but also offers credence to significant contributions in the field. Amongst several building blocks developed by us, the most recent and prominent are presented below. These building blocks have enabled synthesis of several important targets.

ri_pic1
In the second direction, we have been equally successful in our efforts towards the 2-deoxy-C-arylglycosides frame-work, as an important and challenging target from the realm of carbohydrates. Simple approach involving use of aryl acyl anion chemistry has been the basis for this achievement (Organic Letters 2002). The importance of suitable protection necessary to arrive at 2-deoxy-C-aryl glycosides was equally well demonstrated in yet another study (Carbohydrate Research 2003, 338, 2899). Syntheses of Varitriol (Eur. J. Org. Chem. 2010, 555) and C-Glycosylated Phenstatins (Eur. J. Org. Chem. 2010, 4991) as anti-cancer molecules have been the most important achievement in the recent past. In our quest for largely simplified structural motifs towards heparinoid mimetics, synthesis of spaced sugars with lipophilic cores is currently underway.

ri_pic2

COLLABORATION

Besides the above mentioned self propelled achievements, other collaborative initiatives have been equally fruitful. In the first collaborative work with Professor Sheila David in the summer of 2001 (then at Utah and now at UC Davies) we were successful in synthesizing novel trifluoromethyl substituted Adenosine analogue for probing the functions of DNA repair enzymes. Later through the NMITLI project, in collaboration with NCL, we have been successful in developing a new route for the important “building block” used in the synthesis of the multi-billion dollar cholesterol lowering drug-Atorvastatin (Indian Patent, 2006).  In 2009, during collaborative efforts with Physicists in our campus, we have successfully developed a new Distyrylbenzene derivative with Weinreb Amide Functionality functioning as an efficient Laser Dye (Indian Patent Application No.2643/CHE/2008). Very recently another fluorescent probe has been synthesized and examined for multi-photon absorption properties. [Chemical Physics, 2011, 382, 68 - 73]