384365-49-5Relevant academic research and scientific papers
Tropylium-Catalyzed O-H Insertion Reactions of Diazoalkanes with Carboxylic Acids
Empel, Claire,Nguyen, Thanh Vinh,Koenigs, Rene M.
supporting information, p. 548 - 553 (2021/01/26)
Herein, we describe the application of a nonbenzenoid aromatic carbocation, namely tropylium, as an organic Lewis acid catalyst in O-H functionalization reactions of diazoalkanes with benzoic acids. The newly developed protocol is applicable to a wide range of diazoalkane and carboxylic acid substrates with excellent efficiency (43 examples, up to 99% yield).
Blue LED-Mediated N-H Insertion of Indoles into Aryldiazoesters at Room Temperature in Batch and Flow: Reaction Kinetics, Density Functional Theory, and Mechanistic Study
Maiti, Debajit,Das, Ranajit,Sen, Subhabrata
, p. 2522 - 2533 (2021/02/05)
Mild blue light-mediated N-H insertion of indole and its derivatives into aryldiazoesters has been reported in a batch and flow strategy to afford the corresponding N-alkylated product in moderate-to-excellent yield. Detailed high-performance liquid chromatography-based reaction kinetics measurements, control experiments, and kinetic isotope effect reveal that 3-substituted indoles with electron-withdrawing groups such as -CN and -CHO facilitated the product formation, whereas the electron-donating group retarded the process. The neutral indole performed in between them. Furthermore, Hammett plot and density functional theory-based transition-state optimization studies showed substantial correlation of the electronic nature of the substituents at the C3 position of indoles with the rate of the N-H insertion reaction. The strategy was utilized to synthesize a key intermediate for the natural product (-)-psychotrimine.
Blue Light-Emitting Diode-Mediated in Situ Generation of Pyridinium and Isoquinolinium Ylides from Aryl Diazoesters: Their Application in the Synthesis of Diverse Dihydroindolizine
Guha, Souvik,Maiti, Debajit,Prabakar, Tejas,Sar, Saibal,Sen, Subhabrata
, p. 11736 - 11747 (2021/09/02)
Blue light-emitting diode-mediated environmentally sustainable three component reactions among pyridine/isoquinoline 1/2, aryl diazoesters 3, and acrylic ester/3-alkenyl oxindoles 5/6 provide various dihydroindolizines 7 to 9 in excellent yield. The principle of the strategy is photolytic generation of nitrogen ylides from N-heteroarenes and aryl diazoesters and their subsequent [3 + 2] cycloaddition reaction with dipolarophiles. Detailed mechanistic analysis of the transformation through control experiments establishes this strategy as the foundation for the photolytic multicomponent reaction.
Rhodium(I)-Catalyzed Enantioselective C(sp3)—H Functionalization via Carbene-Induced Asymmetric Intermolecular C—H Insertion?
Liu, Bo,Xu, Ming-Hua
supporting information, p. 1911 - 1915 (2021/05/31)
Transition-metal-catalyzed C—H insertion of metal-carbene represents an excellent and powerful approach for C—H functionalization. However, despite remarkable advances in metal-carbene chemistry, transition metal catalysts that are capable of enantioselective intermolecular carbene C—H insertion are mainly constrained to dirhodium(II) and iridium(III)-based complexes. Herein, we disclose a new version of asymmetric carbene C—H insertion reaction with rhodium(I) catalyst. A highly enantioselective rhodium(I) complex-catalyzed C(sp3)—H functionalization of 1,4-cyclohexadienes with α-aryl-α-diazoacetates was successfully developed. By using chiral bicyclo[2.2.2]-octadiene as ligand, rhodium(I)-carbene-induced asymmetric intermolecular C—H insertion proceeds smoothly at room temperature, allowing access to a diverse variety of α-aryl-α-cyclohexadienyl acetates and gem-diaryl-containing acetates in good yields with good to excellent enantioselectivities (up to 99% ee). Furthermore, the synthetic utility of the reaction was highlighted by facile synthesis of a novel cannabinoid CB1 receptor ligand. This method may offer a new opportunity for the development of therapeutically exploitable cannabinoid receptor type ligands in medicinal chemistry.
Blue LED Induced Manganese (I) Catalysed Direct C2?H Activation of Pyrroles with Aryl Diazoesters
Sar, Saibal,Das, Ranajit,Sen, Subhabrata
, p. 3521 - 3531 (2021/06/09)
Herein, we have reported a blue LED mediated manganese pentacarbonyl bromide catalysed incorporation of carbene moieties from aryl diazoesters onto 1H-pyrroles via their selective C2?H activation. A manganese metal-carbene has been identified as the active catalyst to facilitate the reaction. Eighteen mono substituted pyrrole derivatives were isolated in good to excellent yields (67→82%) and the disubstituted products were also formed in minor quantities (5 to 8%). HPLC based kinetics study enabled optimization of the reaction. Control experiments, FT-IR, NMR and GC-MS based characterization elucidated the putative reaction mechanism. (Figure presented.).
Photolytic amino etherification reactions of aryl diazoacetates with N-heterocycles and a stoichiometric amount of dioxane/tetrahydropyran in aqueous medium: Synthesis of 1,4-dioxepane/1,4,7-dioxazonan-6-one systems
Das, Ranajit,Maiti, Debajit,Sen, Subhabrata
, p. 8533 - 8544 (2021/11/17)
Herein we have reported a blue LED mediated reaction of aryl diazoacetate with a stoichiometric amount of 1,4-dioxane/tetrahydropyran (THP) and various heterocycles like indoles, pyrroles, phthalimides, thiazolidinediones and hydantoins in water. During the reaction, various aryl diazoacetates were converted to oxonium ylides by reacting with 1,4-dioxane and THP. These ylides generated in aqueous medium (under metal- and base-free conditions) were then used for the amino etherification of the aforementioned heterocycles in excellent yield. The ylides underwent a [1,2] shift to afford substituted 1,4-dioxepanes. Phthalimide products were also converted to 1,4,7-dioxazonan-6-ones. Reaction kinetics, Hammett's plot and DFT calculations (solvent phase) rationalize the ylide formation and subsequent reactions with the nucleophiles. The reaction was also demonstrated at the multigram scale. This amino etherification reaction of aryl diazoacetates in aqueous medium demonstrated a sustainable process of converting toxic 1,4-dioxane in functionalizing heterocycles. This journal is
A Selective C-C Bond Cleavage Strategy Promoted by Visible Light
Gallo, Rafael D. C.,Duarte, Marcelo,Da Silva, Amanda F.,Okada, Celso Y.,Deflon, Victor M.,Jurberg, Igor D.
supporting information, p. 8916 - 8920 (2021/11/20)
A new visible-light-promoted reaction between aryldiazoacetates and 1,3-diketones allows good yields and selectivities for C-C bond insertions, leading to the corresponding 1,4-dicarbonyl compounds. This transformation is straightforward and highly practical. It tolerates air and moisture and does not require the use of any metals. Mechanistic investigations support the involvement of a key cyclopropanol intermediate derived from an intramolecular rearrangement.
Blue Light-Promoted N?H Insertion of Carbazoles, Pyrazoles and 1,2,3-Triazoles into Aryldiazoacetates
Stivanin, Mateus L.,Fernandes, Alessandra A. G.,da Silva, Amanda F.,Okada, Celso Y.,Jurberg, Igor D.
supporting information, p. 1106 - 1111 (2020/01/25)
Blue light irradiation of aryldiazoacetates leads to the formation of free carbenes, which can react with carbazoles, pyrazoles and 1,2,3-triazoles to afford the corresponding N?H inserted products. These reactions are performed under air and at room temperature, allowing the mild preparation of a variety of motifs found in biologically relevant targets. (Figure presented.).
Room Temperature Coupling of Aryldiazoacetates with Boronic Acids Enhanced by Blue Light Irradiation
da Silva, Amanda F.,Afonso, Marco A. S.,Cormanich, Rodrigo A.,Jurberg, Igor D.
supporting information, p. 5648 - 5653 (2020/04/22)
A visible-light-promoted photochemical protocol is reported for the coupling of aryldiazoacetates with boronic acids. This photochemical reaction shows great enhancement compared to the same protocol performed in the absence of light. Except for a few cases, the room temperature coupling in the dark (thermal process) generally does not work. When it does, it is likely to also involve free carbenes as key intermediates. Alternatively, photochemical reactions show a broad scope, can be performed under air and tolerate a wide variety of functional groups. Reaction-evolution monitoring, DFT calculations and control experiments have been used to evaluate the main aspects of this intricate mechanistic scenario. Biologically active molecules Adiphenine, Benactyzine and Aprophen have been prepared as examples of synthetic applications.
Diastereoselective Trapping of Transient Carboxylic Oxonium Ylides with α,β-Unsaturated 2-Acyl Imidazoles
Zhang, Mengchu,Zhang, Tianyuan,Zhang, Dan,Hu, Wenhao
supporting information, p. 4662 - 4667 (2020/09/23)
By developing a diastereoselective reaction of cyclopropene carboxylic acids with α,β-unsaturated 2-acyl imidazoles, we reported here a Michael-type trapping of transient carboxylic oxonium ylides. This transformation provides a direct approach for the construction of valuable γ-butenolide derivatives in good yields (60–99%) with high diastereoselectivities (up to >95:5 dr) under mild reaction conditions. (Figure presented.).
