Metal Free C–H Functionalization Enabled Diastereoselective Multicomponent Reaction of N-Heterocycles to Fused Heteropolycycles
作者:Sumana Mandal、Soumita Dwari、Chandan K. Jana
DOI:10.1021/acs.joc.8b01105
日期:2018.8.17
A novel C–H functionalization enabled multicomponentreaction involving N-heterocycles, dinucleophile, and dipolarophile has been developed. Direct α- and more challenging β-C(sp3)–H functionalization of aliphatic N-heterocycles was achieved without the use of metallic reagents and oxidants under either conventional or microwave aided heating conditions. In a single operation, up to five carbon–carbon
prototype biomimetic molecular switchers 4-cyclopenten-2'-enylidene-3,4-dihydro-2H-pyrrolinium and its 5,5'-dimethyl derivative both containing the penta-2,4-dieniminium chromophore. To find support for the predicted behavior, we also report the photochemical reaction path of the synthetically accessible compound 4-benzylidene-3,4-dihydro-2H-pyrrolinium. We show that the preparation and photochemical characterization
Direct β-C(sp<sup>3</sup>)–H Functionalization of Aliphatic Amines to α,β-Unsaturated Imines, Aldehydes, and Chromenes
作者:Sumana Mandal、Sujit Mahato、Chandan K. Jana
DOI:10.1021/acs.orglett.5b01744
日期:2015.8.7
functionalization of aliphatic amine was developed. The method is based on a reaction that yields enamine directly from the corresponding aliphatic amine, which otherwise requires the aid of metallic reagent and/or external oxidant. The reaction is operationally simple, general, and highly efficient in functionalizing both cyclic and acyclic amines. Structurally diverse unsaturated imines were obtained from N-heterocycles
Metal-free C–H functionalization of pyrrolidine to pyrrolinium-based room temperature ionic liquid crystals
作者:Sumana Mandal、Ravindra Kumar Gupta、Suraj Kumar Pathak、D. S. Shankar Rao、S. Krishna Prasad、Achalkumar Ammathnadu Sudhakar、Chandan K. Jana
DOI:10.1039/d1nj00647a
日期:——
with low charge distribution in the fully saturated pyrrolidine ring leads to the high melting temperature of the materials due to strong ionic interactions. Herein, the synthesis and evaluation of the structure–property relationship of a new class of pyrrolinium-based ionic liquid crystals has been reported. The metal-free direct C–H functionalization of pyrrolidine, followed by the N-alkylation of resulting
Ring Opening of Pyrrolinium Ions Enabled Regioselective Synthesis of 4-Alkyl <i>N</i>-Arylpyrazoles
作者:Soumita Dwari、Partha Partim Nath、Chandan K. Jana
DOI:10.1021/acs.joc.2c00727
日期:2022.9.16
3-diaryl 4-alkyl pyrazoles has been reported. A wide variety of 1,3-diaryl 4-alkyl pyrazoles were synthesized as a single regioisomer via a ring-opening cyclization reaction of unsaturated pyrrolinium ions in the presence of arylhydrazines. This method avoids using additional alkylation steps and hazardous oxidants that generally are essential for the synthesis of 4-alkyl N-arylpyrazoles.