@article {46275, title = {Route to access imidazol[1,5-a]indole-1,3-diones and pyrrolo[1,2-c]imidazole-1,3-diones}, journal = {Organic \& Biomolecular Chemistry}, volume = {17}, year = {2019}, month = {SEP}, pages = {8384-8390}, type = {Article}, abstract = {

A novel and practical route to synthesize imidazol[1,5-a]indoles and pyrrolo[1,2-c]imidazoles via N-H functionalization has been developed. Indole-2-carboxylic acid or pyrrole-2-carboxylic acid with diverse aniline groups and carbonyldiimidazole (CDI), in the presence of a base under microwave conditions, resulted in imidazol[1,5-a]indoles and pyrrolo[1,2-c]imidazoles, respectively. The present method is free of work-up and no need for column chromatography. Both title scaffolds can serve as useful heterocyclic scaffolds in medicinal chemistry as such, or they can be used as building blocks to construct different classes of useful compounds.

}, doi = {10.1039/c9ob01462d}, author = {Rao, Ramana Sreenivasa and Shajan, Fere Joseph and Reddy, D. Srinivasa} } @article {47399, title = {gamma-Al2O3/triflic acid as cooperative catalysts for the tandem Michael addition/carbocyclization: an easy access to 2-substituted pyrrolo[2,1-a]isoquinolines and 3-substituted pyrrolidine-2,5-diones}, journal = {Journal of Heterocyclic Chemistry}, volume = {58}, year = {2021}, month = {JUL}, pages = {1415-1428}, type = {Article}, abstract = {

A tandem Michael addition/carbocyclization of 3,4-dimethoxyphenethyl maleimide with carbon and sulfur nucleophiles is accomplished via a relay catalysis using gamma-Al2O3/TfOH binary system. The X-ray Photoelectron Spectroscopy (XPS) analysis of binary system indicates the presence of AlF3, AlO(OH) species(.) This approach provides an easy access to 2-aryl or 2-thio aryl pyrrolo[2,1-a]isoquinolines in good yields in a tandem fashion. With suitable ratio of gamma-Al2O3/TfOH binary system, the Michael addition of N/C/S nucleophiles to N-benzyl maleimide is also achieved. A key to the success of these reactions would be the generation of AlF3, AlO(OH) species from gamma-Al2O3 and TfOH, which might have delineated the disadvantageous background reactions usually displayed by a strong Bronsted acid such as TfOH.

}, keywords = {1-a]isoquinolines, 3-substituted pyrrolidine-2, 5-diones, carbocyclization, gamma-Al2O3/TfOH binary system, Michael addition, pyrrolo[2}, issn = {0022-152X}, doi = {10.1002/jhet.4266, Early Access Date = APR 2021}, author = {Rao, Ramana Sreenivasa and Sahani, Anita and Ali, Sheikh Haider and Pradhan, Sumanta and Ramanathan, Chinnasamy Ramaraj} } @article {48764, title = {Scalable synthesis of silacyclohexanones and ready access to silicon building blocks}, journal = {Organic Letters}, volume = {25}, year = {2023}, month = {SEP }, pages = {6881-6885}, type = {Article}, abstract = {

A simple and efficient two-step method for the synthesis of silacyclohexanones starting from bis(bromoethylsilanes) using TosMIC is presented. The prepared silacyclohexanones were transformed to nine different heterocycles with silicon incorporation. In addition, the developed methodology was used for the synthesis of a sila analogue of the HDAC6 inhibitor tubastatin A.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.3c02561}, author = {Ramesh, Eagala and Nandawadekar, Laxman D. and Rao, Ramana Sreenivasa and Reddy, D. Srinivasa} }