R. Srinivasa Rao

Bio: R. Srinivasa Rao is an academic researcher from Indian Institute of Chemical Technology. The author has contributed to research in topics: Aryl & Regioselectivity. The author has an hindex of 18, co-authored 46 publications receiving 958 citations.

Silver Phosphotungstate: A Novel and Recyclable Heteropoly Acid for Friedländer Quinoline Synthesis

Abstract: o-Aminoaryl ketones undergo smooth condensation with α-methylene ketones on the surface of silver heteropoly acid (Ag 3 PW 1 2 O 4 0 ) under mild reaction conditions to afford the corresponding polysubstituted quinolines in excellent yields with high selectivity. The catalyst can be recovered by simple filtration and can be recycled in subsequent reactions.

A Novel L-Proline Catalyzed Biginelli Reaction : One-Pot Synthesis of 3, 4-Dihydropyrimidin-2(1H)-ones under Solvent-Free Conditions

Abstract: A Novel efficient and simple synthetic protocol for the Biginelli reaction has been developed for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones in a one-pot three-component condensation of aldeh...

Synthesis of new chromeno-annulated cis-fused pyrano[3,4-c]pyran derivatives via domino Knoevenagel–hetero-Diels–Alder reactions and their biological evaluation towards antiproliferative activity

Abstract: A new series of chromeno-annulated cis-fused pyrano[3,4-c]pyran derivatives have been synthesized by intramolecular [4 + 2] domino Knoevenagel–hetero-Diels–Alder reactions of 1-oxa-1,3-butadienes derived in situ from 1,3-dicarbonyls/active methylenes and 7-O-prenyl derivatives of 8-formyl-2,3-disubstituted chromenones in the presence of 20 mol% ethylenediamine diacetate (EDDA) in acetonitrile under reflux conditions in good to excellent yields. The structures were established based on spectroscopic data, and were further confirmed by X-ray diffraction analysis. These compounds were evaluated for their anti-proliferative activity using an in vitro MTT cytotoxicity assay. The results clearly demonstrated that compounds 4a, 4b, 4c, 4j, 4k, 4l, 4m and 4n exhibited significant anti-proliferative activity against human A549 lung cancer and non-cancer MRC-5 cell lines along with potent inhibitory activity against human neuroblastoma SK-N-SH cancer cell lines. Among these, compounds 4a, 4b and 4j displayed the most potent anti-proliferative activity against human lung cancer A549 cell lines, while 4a and 4b displayed against neuroblastoma SK-N-SH cancer cell lines when compared to the standard doxorubicin.

Alternative synthetic methods through new developments in catalysis by gold.

Abstract: 2.7. Hydroxylation Reactions of Allenes 3282 2.8. Hydroamination Reactions of Allenes 3284 2.9. Hydrothiolation of Allenes 3284 2.10. Hydroalxoxylation of Alkenes and 1,3-Dienes 3286 2.11. Hydroamination of Alkenes and 1,3-Dienes 3287 2.12. Hydrothiolation of Conjugated Olefins 3289 3. Activation of Carbonyl/Imine Groups and Alcohols 3289 3.1. Condensation Reactions 3289 3.2. Addition Reactions 3291 3.3. Aldol Reactions 3294 3.4. Hydroand Carbosilylation Reactions 3295 3.5. Nucleophilic Substitution Reactions of Alcohols 3297 4. Gold-Catalyzed C-H Bond Functionalization 3297 4.1. Csp3-H Bond Functionalization 3298 4.2. Csp2-H Bond Functionalization 3299 4.3. Csp-H Bond Functionalization 3304 5. Gold-Catalyzed Selective Reductions 3305 5.1. Catalytic Hydrogenation of Alkenes 3306 5.2. Selective Reductions of R, -Unsaturated Carbonyl Groups and 1,3-Dienes 3306

Multi-component syntheses of heterocycles by transition-metal catalysis

Abstract: For a long time multi-component syntheses of heterocycles have undeniably been a domain of classical carbonyl condensation chemistry. However, the advent of transition-metal catalysis not only has fertilized strategies in heterocyclic synthesis by uni- and bimolecular transformations but the past decade has also witnessed a rapid development of transition-metal catalysis in new multi-component reactions (MCR). Expectedly, palladium catalyzed processes have received a dominant position, yet, other transition-metal complexes are catching up implying organometallic elementary steps that reach even further than cross-coupling and carbometallation. Besides domino MCRs that are purely based upon organometallic catalysis the sequential and consecutive combination with condensation, addition and cycloaddition steps opens a vast playground for the invention of new sequences in heterocyclic synthesis. This tutorial review outlines the underlying reaction based principles of transition-metal catalysis in multi-component syntheses of heterocycles, summarizes recent developments of palladium catalyzed MCR, and highlights the more recent contributions to MCR based heterocyclic synthesis by virtue of rhodium, ruthenium, and copper catalysis.