@article { ISI:000378303400056, title = {Nucleophilic nitration of arynes by sodium nitrite and its multicomponent reaction leading to double-functionalized arenes}, journal = {Organic Letters}, volume = {18}, number = {12}, year = {2016}, month = {JUN}, pages = {3010-3013}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

An unusual nucleophilic nitration of arynes by NaNO2 in the presence of water has been developed, and the concept was further demonstrated to accomplish a double functionalization of arynes using a multicomponent reaction protocol to synthesize pharmaceutically important (2-nitrophenyl)methanol derivatives. Such substitution ortho to -NO2 is difficult by other means. The reaction conditions are mild and avoid the use of strong acids, expensive transition metal catalysts, and additives.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.6b01384}, author = {Dhokale, Ranjeet A. and Mhaske, Santosh B.} } @article {48343, title = {Nickel-catalyzed direct synthesis of N-substituted indoles from amino alcohols and alcohols}, journal = {Organic Letters}, volume = {24}, year = {2022}, month = {DEC}, pages = {9054-9059}, type = {Article}, abstract = {

A one-pot cascade approach for the synthesis of N substituted indoles from amino alcohols and alcohols under additive and base-free conditions with the liberation of water as the only stoichiometric byproduct is reported. The commercially available bench-stable Ni(OTf)2 salt in combination with 1,2-bis(dicyclohexylphosphino)ethane (dcype) is very effective for this unprecedented catalytic transformation. A broad range of substrates including aromatic and aliphatic primary alcohols, cyclic and acyclic secondary alcohols, and various substituted 2-aminophenyl ethyl alcohols are employed in the reaction conditions to provide a diverse range of N-alkylated indoles. Mechanistic studies revealed that the reaction proceeds through tandem N-alkylation via hydrogen autotransfer followed by the cyclization of N-alkylated alcohol intermediate.

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.2c03617}, author = {Yadav, Vinita and Jagtap, Sayali G. and Balaraman, Ekambaram and Mhaske, Santosh B.} } @article {49684, title = {NHC-catalyzed allylation of aldehydes with MBH carbonates and their michael addition-elimination-cope rearrangement cascade: a route to rac-sacubitril}, journal = {Organic Letters}, volume = {27}, year = {2025}, month = {MAY}, pages = {5911-5916}, type = {Article}, abstract = {

We report herein a novel NHC-catalyzed transition-metal-free chemoselective allylation of aldehydes with Morita-Baylis-Hillman (MBH) carbonates using an inorganic base. Fascinatingly, the use of an organic base follows a different mechanism, leading to highly functionalized 1,5-dienes via a Michael addition-elimination reaction followed by [3,3]-sigmatropic Cope rearrangement. The described method harnesses a new Csp2-Csp3 bond to access alpha-methylene-gamma-oxo-gamma-substituted ester derivatives paving a way to facile synthesis of potent natural products and active pharmaceutical ingredients (APIs). A broad range of aromatic and aliphatic aldehydes with MBH carbonates was employed to provide a variety of interesting butanoate and dienyl ketone scaffolds in good to excellent yields. This chemistry has been extended to the efficient syntheses of rac-sacubitril API and gamma-butyrolactone scaffold, which is a privileged core present in many natural products and APIs

}, issn = {1523-7060}, doi = {10.1021/acs.orglett.5c01820}, author = {Kale, Tushar B. and Jagtap, Sayali G. and Mhaske, Santosh B.} }