Gold-Catalyzed Site-Selective C−H Bond Functionalization with Diazo Compounds

2018 ◽  
Vol 7 (10) ◽  
pp. 2015-2025 ◽  
Author(s):  
Ben Ma ◽  
Lu Liu ◽  
Junliang Zhang
Keyword(s):  
Diazo Compounds ◽  
Bond Functionalization ◽  
Site Selective

Theoretical and experimental studies of palladium-catalyzed site-selective C(sp3)−H bond functionalization enabled by transient ligands

2017 ◽  
Author(s):  
Haibo Ge ◽  
Lei Pan ◽  
Piaoping Tang ◽  
Ke Yang ◽  
Mian Wang ◽  
...  
Keyword(s):  
Bond Activation ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Bond Functionalization ◽  
Aliphatic Ketones ◽  
Site Selectivity ◽  
Mechanistic Investigation ◽  
Palladium Catalyzed ◽  
Metal Catalyzed ◽  
Site Selective

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp<sup>3</sup> carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp<sup>3</sup>)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp<sup>3</sup>)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.<br><br>

Highly Site-Selective Direct C−H Bond Functionalization of Unactivated Arenes with Propargyl α‑Aryl-α-diazoacetates via Scandium Catalysis

2021 ◽  
Author(s):  
Balu S. Navale ◽  
Debasish Laha ◽  
Subhrashis Banerjee ◽  
Kumar Vanka ◽  
Prof. Dr. Ramakrishna G. Bhat
Keyword(s):  
The Novel ◽  
Bond Functionalization ◽  
Site Selective

<p>Highly chemo- and regio-selective C–H bond functionalization of unactivated arenes with propargyl <i>α</i>-aryl-<i>α</i>-diazoacetates is developed using scandium catalysis. Variety of unactivated, mildly deactivated and electronically activated arenes are functionalized using this protocol. We have explored the novel combination of scandium triflate and propargyl <i>α</i>-aryl-<i>α</i>-diazoacetate as catalyst-reagent system for the effective C–H bond functionalization. The protocol avoids the use of expensive catalysts and practicality of the protocol has been demonstrated by the gram scale synthesis of very useful <i>α</i>-diarylacetates including antispasmodic drug-adephenine.</p>

scholarly journals Recent Advances in Palladium-Catalyzed Bridging C–H Activation by Using Alkenes, Alkynes or Diazo Compounds as Bridging Reagents

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 238-254
Author(s):  
Fulin Zhang ◽  
Luoting Xin ◽  
Saihu Liao ◽  
Xueliang Huang ◽  
Yinghua Yu
Keyword(s):  
Bond Distance ◽  
Short Review ◽  
Diazo Compounds ◽  
Bond Functionalization ◽  
Migratory Insertion ◽  
Intramolecular Reactions ◽  
Palladium Catalyzed ◽  
Direct Functionalization ◽  
Intermolecular Reactions ◽  
Metal Catalyzed

AbstractTransition-metal-catalyzed direct inert C–H bond functionalization has attracted much attention over the past decades. However, because of the high strain energy of the suspected palladacycle generated via C–H bond palladation, direct functionalization of a C–H bond less than a three-bond distance from a catalyst center is highly challenging. In this short review, we summarize the advances on palladium-catalyzed bridging C–H activation, in which an inert proximal C–H bond palladation is promoted by the elementary step of migratory insertion of an alkene, an alkyne or a metal carbene intermediate.1 Introduction2 Palladium-Catalyzed Alkene Bridging C–H Activation2.1 Intramolecular Reactions2.2 Intermolecular Reactions3 Palladium-Catalyzed Alkyne Bridging C–H Activation3.1 Intermolecular Reactions3.2 Intramolecular Reactions4 Palladium-Catalyzed Carbene Bridging C–H Activation5 Conclusion and Outlook

Rhodium-catalyzed triazole-directed C–H bond functionalization of arenes with diazo compounds

2018 ◽  
Vol 16 (43) ◽  
pp. 8191-8195 ◽  
Author(s):  
Huanhong Wang ◽  
Xiaofei Yi ◽  
Yanli Cui ◽  
Wanzhi Chen
Keyword(s):  
Diazo Compounds ◽  
Bond Functionalization ◽  
Alkylation Reactions

Rhodium(iii)-catalyzed alkylation reactions of arenes through triazole directed C–H activation that lead to a number of dialkylated and monoalkylated triazoles are described.

scholarly journals Site-Selective A-C-H Functionalization of Trialkylamines via Reversible Hydrogen Atom Transfer Catalysis

2021 ◽  
Author(s):  
Yangyang Shen ◽  
Franziska Schoenebeck ◽  
Ignacio Funes-Ardoiz ◽  
Tomislav Rovis
Keyword(s):  
Drug Discovery ◽  
Hydrogen Atom ◽  
Late Stage ◽  
Hydrogen Atom Transfer ◽  
Atom Transfer ◽  
Bond Functionalization ◽  
Carbon Centers ◽  
Radical Trapping ◽  
Site Selectivity ◽  
Site Selective

Trialkylamines are widely found in naturally-occurring alkaloids, synthetic agrochemicals, biological probes, and especially pharmaceuticals agents and pre-clinical candidates. Despite the recent breakthrough of catalytic alkylation of dialkylamines, the selective a-C(sp3 )–H bond functionalization of widely available trialkylamine scaffolds holds promise to streamline complex trialkylamine synthesis, accelerate drug discovery and execute late-stage pharmaceutical modification with complementary reactivity. However, the canonical methods always result in functionalization at the less-crowded site. Herein, we describe a solution to switch the reaction site through fundamentally overcoming the steric control that dominates such processes. By rapidly establishing an equilibrium between a-amino C(sp3 )-H bonds and a highly electrophilic thiol radical via reversible hydrogen atom transfer, we leverage a slower radical-trapping step with electron-deficient olefins to selectively forge a C(sp3 )-C(sp3 ) bond with the more-crowded a-amino radical, with the overall selectivity guided by Curtin-Hammett principle. This subtle reaction profile has unlocked a new strategic concept in direct C-H functionalization arena for forging C– C bonds from a diverse set of trialkylamines with high levels of site-selectivity and preparative utility. Simple correlation of site-selectivity and 13C NMR shift serves as a qualitative predictive guide. The broad consequences of this dynamic system, together with the ability to forge N-substituted quaternary carbon centers and implement late-stage functionalization techniques, holds tremendous potential to streamline complex trialkylamine synthesis and accelerate drug discovery

scholarly journals Mechanism of Side Reactions in Alkane CH Bond Functionalization by Diazo Compounds Catalyzed by Ag and Cu Homoscorpionate Complexes-A DFT Study

ChemCatChem ◽  
2011 ◽  
Vol 3 (10) ◽  
pp. 1646-1652 ◽  
Author(s):  
Ataualpa A. C. Braga ◽  
Ana Caballero ◽  
Juan Urbano ◽  
M. Mar Diaz-Requejo ◽  
Pedro J. Pérez ◽  
...  
Keyword(s):  
Dft Study ◽  
Diazo Compounds ◽  
Side Reactions ◽  
Bond Functionalization
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