Silver(I)–Ferrophox Catalyzed Enantioselective Desymmetrization of Cyclopentenedione: Synthesis of Highly Substituted Bicyclic Pyrrolidines
作者:Tapas Das、Prasenjit Saha、Vinod K. Singh
DOI:10.1021/acs.orglett.5b02582
日期:2015.10.16
A highly enantioselective desymmetrization of prochiral cyclopentene-1,3-dione via [3 + 2] cycloaddition of azomethine ylide using a silver(I)–ferrophox complex has been demonstrated. The method has been utilized in the synthesis of highly functionalized enantioenriched 5,5-fused bicyclic pyrrolidine derivatives under mild reaction conditions.
Sequential Reduction of Nitroalkanes Mediated by CS<sub>2</sub> and Amidine/Guanidine Bases: A Controllable Nef Reaction
作者:Minsoo Ju、Weiyang Guan、Jennifer M. Schomaker、Kaid C. Harper
DOI:10.1021/acs.orglett.9b02987
日期:2019.11.15
In this letter, we describe a mild, functional group-tolerant reductive Nef reaction that utilizes CS2 and an amidine or guanidine base to sequentially cleave N–O bonds. These conditions transform secondary nitroalkanes to ketones via an isolable oxime with minimal erosion at labile stereogenic carbons, show excellent compatibility with groups sensitive to oxidizing or reducing conditions, display
PhIO as a Powerful Cyclizing Reagent: Regiospecific [3+2]-Tandem Oxidative Cyclization of Imine toward Cofacially Self-Aggregated Low Molecular Mass Organic Materials
作者:Palash Pandit、Nirbhik Chatterjee、Samiran Halder、Sandip K. Hota、Amarendra Patra、Dilip K. Maiti
DOI:10.1021/jo8028136
日期:2009.3.20
The powerful cyclization and tandem oxidation property of environmentallybenign PhIO is developed for the first time, which leads to regiospecific [3+2]-tandem oxidative cyclization of imine at room temperature in rapid access to a new class of compounds, 1,2-functionalized 4,5-diarylimidazoles, in excellent yield with synthetic efficiency. Size, shape, and activity of the involved nanoreactors for
Highly fluorescent 1,2-dihydropyrimido[1,6-α]indole: an efficient metal free synthesis and photophysical study
作者:Tapas Das、Anirban Kayet、Ruchika Mishra、Vinod K. Singh
DOI:10.1039/c6cc05378e
日期:——
A metal free route to highly fluorescent 1,2-dihydropyrimido[1,6-[small alpha]]indole derivatives has been developed via base catalyzed aldol followed by Mannich reaction of indole-2-carboxaldehyde with azomethine ylides at room temperature. This transformation...
(<i>R</i>)-DM-SEGPHOS–Ag(I)-Catalyzed Enantioselective Synthesis of Pyrrolidines and Pyrrolizidines via (1,3)- and Double (1,3)-Dipolar Cycloaddition Reactions
作者:Sumit K. Ray、Rayhan G. Biswas、Arun Suneja、Milon M. Sadhu、Vinod K. Singh
DOI:10.1021/acs.joc.7b03185
日期:2018.2.16
diastereo- and enantioselective route to access a wide range of highly substituted pyrrolidine and pyrrolizidine derivatives has been described via (1,3)- and double (1,3)-dipolar cycloaddition reactions catalyzed by the (R)-DM-SEGPHOS–Ag(I) complex. The reactions proceed smoothly at ambient temperature, affording a variety of pyrrolidines and pyrrolizidines in high yields (up to 93%) with up to 99:1 dr and