Rh(III)-Catalyzed C(8)–H Activation of Quinoline <i>N</i>-Oxides: Regioselective C–Br and C–N Bond Formation

Dhiman, Ankit Kumar; Gupta, Shiv Shankar; Sharma, Ritika; Kumar, Rakesh; Sharma, Upendra

doi:10.1021/acs.joc.9b01538

Cited by 37 publications

(22 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Inspired by this work, the group of Sharma reported in 2019 two new Rh-based protocols to achieve the C8 regioselective formation of C-Br and C-N bonds on quinoline N -oxides [ 194 ]. Regarding the bromination method, various reaction parameters were studied to rapidly optimize the model reaction involving N -bromosuccinimide (NBS, 1.1 equiv), [RhCp*Cl 2 ] 2 (5 mol%) and AgSbF 6 (20 mol%) in trifluoroethanol, and addition of NaOAc (20 mol%) proved to be beneficial.…”

Section: Functionalization In Positionmentioning

confidence: 99%

Regioselective Functionalization of Quinolines through C-H Activation: A Comprehensive Review

Gravier‐Pelletier

Busca

2021

Molecules

View full text Add to dashboard Cite

Quinoline is a versatile heterocycle that is part of numerous natural products and countless drugs. During the last decades, this scaffold also became widely used as ligand in organometallic catalysis. Therefore, access to functionalized quinolines is of great importance and continuous efforts have been made to develop efficient and regioselective synthetic methods. In this regard, C-H functionalization through transition metal catalysis, which is nowadays the Graal of organic green chemistry, represents the most attractive strategy. We aim herein at providing a comprehensive review of methods that allow site-selective metal-catalyzed C-H functionalization of quinolines, or their quinoline N-oxides counterparts, with a specific focus on their scope and limitations, as well as mechanistic aspects if that accounts for the selectivity.

show abstract

Section: Functionalization In Positionmentioning

confidence: 99%

Regioselective Functionalization of Quinolines through C-H Activation: A Comprehensive Review

Gravier‐Pelletier

Busca

2021

Molecules

View full text Add to dashboard Cite

show abstract

“…Tosylazide and dioxazolone also provide amidated product in the optimized reaction conditions (Scheme 19a, 19b). [46] In 2019, Sharma group disclosed the method in which oxygen is used as an oxidant which is environment friendly. Moreover, oxygen use replaces the use of toxic metal oxidants under various Rh(III)-catalysis.…”

Section: Rh(iii)-catalyzed C(sp )à H Functionalization Of Quinolinesmentioning

confidence: 99%

“…The reaction has a broad substrate scope and mild conditions under Rh(III)‐catalysis. Tosylazide and dioxazolone also provide amidated product in the optimized reaction conditions (Scheme a, 19b) …”

Section: Rh(iii)‐catalyzed C(sp2)−h Functionalization Of Quinolinesmentioning

confidence: 99%

Rhodium‐Catalyzed Selective C−H Bond Functionalization of Quinolines

et al. 2020

Self Cite

View full text Add to dashboard Cite

In the last two decades, rhodium-based catalysts have been used extensively for the sp 2 and sp 3 CÀ H bond activation/functionalization of various arenes, heteroarenes, and aliphatic compounds, respectively. For quinoline functionalization rhodium has been used significantly as compared to other transition metals such as cobalt, copper, ruthenium, palladium and iridium. In this Minireview the progress on rhodium-catalyzed selective functionalization of quinoline N-oxides and 8-methylquinolines via sp 2 and sp 3 CÀ H bond activation, respectively have been highlighted. The main focus is on reaction mechanism, substrate scope, and positional selectivity.

show abstract

“…29,30 Moreover, quinoline N-oxides are vital precursors 31,32 for the synthesis of various quinoline derivatives, which cannot be easily accessed from quinoline due to its low activity and poor regioselectivity. [33][34][35][36] Despite the above mentioned superior properties and vast applications, the synthesis of quinoline N-oxides is considerably underdeveloped. Previously reported methods for the synthesis of quinoline N-oxides include the oxidation of quinolines, 37,38 reductive cyclization reaction of 2nitrochalcones, 39 and others.…”

Section: Introductionmentioning

confidence: 99%

Facile Fabrication of Hierarchical MOF–Metal Nanoparticle Tandem Catalysts for the Synthesis of Bioactive Molecules

Chen

Zhang

et al. 2020

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Multifunctional metal-organic frameworks (MOFs) that possess permanent porosity are promising catalysts in organic transformation. Herein, we report the construction of a hierarchical MOF functionalized with basic aliphatic amine groups and polyvinylpyrrolidone-capped platinum nanoparticles (Pt NPs). The postsynthetic covalent modification of organic ligands increases basic site density in the MOF and simultaneously introduces mesopores to create a hierarchically porous structure. The multifunctional MOF is capable of catalyzing a sequential Knoevenagel condensation-hydrogenation-intramolecular cyclization reaction. The unique selective reduction of the nitro group to intermediate hydroxylamine by Pt NPs supported on MOF followed by intramolecular cyclization with a cyano group affords an excellent yield (up to 92%) to the uncommon quinoline N-oxides over quinolines. The hierarchical MOF and polyvinylpyrrolidone capping agent on Pt NPs synergistically facilitate the enrichment of substrates and thus lead to high activity in the reduction-intramolecular cyclization reaction. The bioactivity assay indicates that the synthesized quinoline N-oxides evidently inhibit the proliferation of lung cancer cells. Our findings demonstrate the feasibility of MOF-catalyzed direct synthesis of bioactive molecules from readily available compounds under mild conditions.

show abstract

Rh(III)-Catalyzed C(8)–H Activation of Quinoline N-Oxides: Regioselective C–Br and C–N Bond Formation

Cited by 37 publications

References 52 publications

Regioselective Functionalization of Quinolines through C-H Activation: A Comprehensive Review

Regioselective Functionalization of Quinolines through C-H Activation: A Comprehensive Review

Rhodium‐Catalyzed Selective C−H Bond Functionalization of Quinolines

Facile Fabrication of Hierarchical MOF–Metal Nanoparticle Tandem Catalysts for the Synthesis of Bioactive Molecules

Contact Info

Product

Resources

About