A5039719616- Catalytic C–H Functionalization Methods
- X-ray Diffraction in Crystallography
- Crystallization and Solubility Studies
- Catalytic Cross-Coupling Reactions
- Asymmetric Hydrogenation and Catalysis
- Synthesis and Catalytic Reactions
- Cyclopropane Reaction Mechanisms
- Chemical Synthesis and Analysis
- Synthesis of heterocyclic compounds
- Sulfur-Based Synthesis Techniques
- Chemical Synthesis and Reactions
- Synthetic Organic Chemistry Methods
- Synthesis and Properties of Aromatic Compounds
- Synthesis of Indole Derivatives
- Radical Photochemical Reactions
- Crystallography and molecular interactions
- Organic Electronics and Photovoltaics
National Institute of Science Education and Research
2020-2024
Homi Bhabha National Institute
2022-2024
In recent years, transition metal-catalyzed strong C–C bond activation has significantly attracted the attention of synthetic chemists. This protocol enables simultaneous and direct functionalization two different M–C bonds. Among types strategies, strain-driven resulted in various otherwise difficult transformations. this context, palladium catalyst been extensively used studied due to its robust reactivity selectivity. Herein we have briefly discussed palladium-catalyzed three-...
This review focuses on providing comprehensive highlights of the recent advances in field cobalt-catalysed C–H functionalization and related synthetic concepts, relying these through oxygen atom coordination.
A new strategy for the C(7)-H functionalization of indoline derivatives using first-row transition-metal cobalt has been demonstrated wherein pivaloyl group acts as a weakly coordinating directing group. Biologically important pyroquilon (tetrahydropyroquinolinone) have synthesized in one-pot manner through selective and concomitant cyclization. In this process, aromatic C–H amidic C–N bonds are cleaved, C–C formed step-economical fashion. Further, alkenylation also accomplished activated...
Strain-driven palladium/N-heterocyclic carbene-catalyzed C–C bond activation of diphenylcyclopropenone (DPC) has been explored for one-step access to trisubstituted α,β-unsaturated esters and amides. The designed transformation works under mild conditions providing exclusively a single stereoisomer. Mechanistic studies support the oxidative addition cyclopropenone in-situ-generated Pd(0) intermediate. We have proved that vinylic hydrogen in product is coming from phenol/aniline through...
Co(III)-catalyzed alkenylation of 2-pyridones by using terminal alkyne as a reaction partner with high regioselectivity has been demonstrated for the first time. The conditions are mild and compatible wide range substrate combinations. It also shows good functional group tolerance. proceeds through cyclometalation followed insertion protodemetalation steps. formation five- seven-membered cobaltacycle intermediates was detected high-resolution mass spectrometry.
A new application of hydroxylamine‐ O ‐sulfonic acid (HOSA) has been discovered whereby aromatic ketones react with HOSA and alkynes to form isoquinolines in the presence a Rh III catalyst. This C–H/N–O annulation methodology gives excellent yields even without any silver additive, acid/base or metal oxidant. is first report wherein directing group simultaneously forming situ, acting as also an internal
A rhodium-catalyzed oxidative C-H/N-H dehydrogenative [3 + 2] annulation strategy has been reported between anilines and N-allylbenzimidazole for the synthesis of 2-methylindole scaffolds. An used as a 2C synthon indole, more importantly, this transformation involves cleavage thermodynamically stable C-N bond allylamine. Detailed mechanistic studies have performed key intermediate was detected in HRMS. This proceeds through cascade C(sp2)-H allylation followed by intramolecular cyclization.
A catalytic system is discovered for the intramolecular C–H amidation of N-phenoxy acetamide derivatives. Herein, a cobalt catalyst has been employed olefin-mediated ortho functionalization. Moreover, monocyclic olefin, maleimide, used as transient mediator instead well-established bicyclic norbornenes. Maleimide promotes Co(III) intermediate to undergo oxidative addition into O–N bond form Co(V) nitrene species and subsequently directs position. Mechanistic study density functional theory...
A Rh-catalyzed pot and step economic synthesis of aza-polycyclic aromatic hydrocarbons (N-PAHs) from readily available aryl ketones alkynes has been disclosed. Additionally, a novel synthetic application the well-known aminating reagent hydroxylamine-O-sulfonic acid (HOSA) explored as an in situ redox-neutral directing group for formation N-PAHs via isoquinoline. Multiple bond single operation through cascade triple C–H activations is beauty this protocol. The challenging annulations two...
We report herein a cobalt-catalyzed 8-aminoquinoline-directed highly regio- and stereoselective C-H/N-H activation annulation of indole-2-carboxamides with 1,2-dihydronaphthalene for the synthesis β-carboline-1-one derivatives at room temperature. A cheaper commercially available cobalt catalyst has been used this transformation. The protocol tolerates wide range functionalities, affording in good yields. An initial mechanistic study revealed reversible cyclometalation to be operative.
A Rh-catalyzed C(sp2)-H propenylation has been reported by taking N-allyl benzimidazole as an allylamine congener. This transformation observed for the first time, where a tandem process of C-H allylation followed alkene isomerization delivers highly stereoselective trans-propenylated product. Detailed mechanistic studies including characterization rhodacycle-intermediates have conducted to understand mechanism.
A Ni-catalyzed C–N bond activation of 2-pyridylpyridone and 1-(9-alkyl 9H-purin-6-yl)pyridin-2(1H)-one coupling with arylboronic acid have been achieved. unique feature this reaction is the strategic bridging replacement pyridone unit aryl groups using nickel catalyzed Suzuki–Miyaura coupling. This provides an exciting new tool to build C–C bonds in place pyridones. wide variety substrates boronic acids are amenable transformation. More importantly, we successfully synthesized a...