@article {49349, title = {2,3-Difunctionalization of quinones: a gold-catalyzed cascade approach for trifluoromethyl-amination or sulfoximination}, journal = {Chemical Communications}, volume = {60}, year = {2024}, month = {AUG }, pages = {9598-9601}, type = {Article}, abstract = {

A one-pot domino protocol employing gold(i) catalysis has been developed for the cascade trifluoromethyl-amination/sulfoximination of quinones. Togni I serves as the trifluoromethyl installing precursor, while amine or sulfoximine serves as the aminating source. Preliminary investigations suggest a mutual activation of Togni I and the amine precursor, facilitating the facile difunctionalization of quinones with excellent regioselectivity. Extensive substrate scope exploration demonstrates moderate to good yields of difunctionalized products. Application to the natural product Juglone highlights its potential for late-stage modifications in medicinal chemistry and drug discovery. A one-pot domino protocol employing gold(i) catalysis has been developed for the cascade trifluoromethyl-amination/sulfoximination of quinones.

}, issn = {1359-7345}, doi = {10.1039/d4cc01891e}, author = {Sharma, Alpa and Govande, Vijaya and Mahajan, Shivangani and Sawant, Sanghapal D.} } @article {49359, title = {C-H functionalization of imidazo[1,5-a]pyridines: a metal-free approach for methylene insertion to access C(sp2)-C(sp3)-H-C(sp2) bond formation}, journal = {ACS Omega}, volume = {9}, year = {2024}, month = {DEC }, pages = {49071-49080}, type = {Article}, abstract = {

Formaldehyde has been used as a solvent and a source of carbon to insert a methylene group for bridging two imidazo[1,5-a]pyridine molecules without using any metal catalysis. This strategy has been extended on other alkyl-, aryl-, and heteroaryl aldehydes as well. This C(sp2)-C(sp3)-H-C(sp2) bond forming reaction proceeds via C(sp2)H functionalization of imidazo[1,5-a]pyridine and was applied on a wide range of substrates offering moderate to good yields of methylene-bridged/inserted bis-imidazo[1,5-a]pyridines. Most importantly, as an application, the bis-heteroarene product has been demonstrated as a ligand. The ligand-like behavior of bis-imidazo[1,5-a]pyridines has been demonstrated as an extension of current methodology. This reaction works well at the gram scale level.

}, issn = {2470-1343}, doi = {10.1021/acsomega.4c03823}, author = {Mahajan, Shivangani and Sawant, Sanghapal D.} } @article {49086, title = {Diastereoselective synthesis of functionalized spiroindolines via intramolecular ipso-iodocyclization/nucleophile addition cascade reactions of indole-tethered ynones}, journal = {Organic and biomolecular chemistry}, volume = {22}, year = {2024}, month = {MAY }, pages = {3415-3419}, type = {Article}, abstract = {

Herein, we describe a highly diastereoselective approach for synthesizing polyfunctionalized spiroindolines from indolyl-ynones involving an ipso-iodocyclization/nucleophile addition cascade. The developed strategy allows the formation of a spirocyclic core and the installation of two functional groups in a single operation. Also this strategy is accompanied by the generation of two C-C and one C-I bonds and two contiguous stereocenters.

}, issn = {1477-0520}, doi = {10.1039/d4ob00112e}, author = {Bag, Debojyoti and Sawant, Sanghapal D.} } @article {49228, title = {Divergent synthesis of unsymmetrical Bis-heteroaryl ketones via base-promoted cascade reactions of 1,2-alkynedione-derived N-propargylic β-enaminones}, journal = {JOURNAL OF ORGANIC CHEMISTRY}, volume = {89}, year = {2024}, month = {AUG }, pages = {11665-11670}, type = {Journal Article}, keywords = {ASYMMETRIC-SYNTHESIS, heterocycles, intramolecular cyclization, pyrroles}, issn = {0022-3263}, doi = {10.1021/acs.joc.4c01407}, author = {Bag, Debojyoti and Saini, Sheetal and Rathod, Mahesh S. and Sawant, Sanghapal D.} } @article {49048, title = {I2-catalyzed three-component synthesis of 3-selenylated pyrazolo[1,5-a]pyrimidines}, journal = {New Journal of Chemistry}, volume = {48}, year = {2024}, month = {MAY }, pages = {9480-9485}, type = {Article}, abstract = {

A straightforward protocol has been developed to access 3-selenylated pyrazolo[1,5-a]pyrimidines from readily available amino pyrazoles, chalcones, and diaryl/dialkyl diselenides. This I-2-catalyzed methodology is highly useful for synthesizing a wide range of functionalized 3-(aryl/alkylselanyl)pyrazolo[1,5-a]pyrimidine derivatives. Mechanistic investigation disclosed that iodine catalysis is very important in both the cyclization process as well as in the C-H selenylation step. Moreover, the developed reaction conditions are also applicable for the cyclization of amino pyrazole with enaminone followed by C-H selenylation in one pot. The use of simple reagents and catalyst, wide substrate scope, mild and metal-free reaction conditions, and practical applicability are the attractive facets of this approach.

}, issn = {1144-0546}, doi = {10.1039/d3nj05847f}, author = {Choudhuri, Tathagata and Paul, Suvam and Sikdar, Papiya and Das, Sourav and Sawant, Sanghapal D. and Bagdi, Avik Kumar} } @article {49353, title = {Modular synthesis of unsymmetrical indolyl diketones from ynediones via sequential aza-Michael addition/C-H functionalization}, journal = {Organic \& Biomolecular Chemistry}, volume = {22}, year = {2024}, month = {OCT }, pages = {8152-8156}, type = {Article}, abstract = {

Herein, we disclose an efficient approach for the synthesis of unsymmetrical indolyl diketones from easily accessible 1,2-alkynediones involving a sequential aza-Michael addition/C-H Functionalization process. The two-step, one-pot strategy involves the aza-Michael addition of an aniline generating the N-aryl enaminones followed by iodine-mediated C-H functionalization.

}, issn = {1477-0520}, doi = {10.1039/d4ob00946k}, author = {Naveed, Abdul and Bag, Debojyoti and Sawant, Sanghapal D.} }