22065-57-2Relevant academic research and scientific papers
White-light emission from a structurally simple hydrazone
Shao, Baihao,Stankewitz, Nell,Morris, Jacob A.,Liptak, Matthew D.,Aprahamian, Ivan
, p. 9551 - 9554 (2019)
Two hydrazones featuring a unique excitation wavelength-dependent dual fluorescence emission have been developed. The mixing extent of the two emission bands can be modulated by tuning the excitation wavelength, resulting in multicolor and even white light emission from structurally simple hydrazones.
Copper-Catalyzed Selective Pyrrole Functionalization by Carbene Transfer Reaction
Rodríguez, Anabel M.,Molina, Francisco,Díaz-Requejo, M. Mar,Pérez, Pedro J.
, p. 1998 - 2004 (2020)
1H-Pyrroles can be directly functionalized by means of the incorporation of carbene groups from diazo compounds, in a process catalyzed by TpxCu complexes (Tpx=hydrotrispyrazolylborate ligand). The reactions take place with a complete selectivity toward the formal insertion of the carbene into the Cα?H bond, leading to alkylated pyrroles, with no modification of the Cβ?H, N?H or C=C bonds of the pyrrole unit. Alkyl substituents at C-ring as well as alkyl, aryl, allyl or alkyne substitution at N atom are tolerated, the strategy affording 20 new pyrrole derivatives. The observance of partial deuteration at the methylene group when the reaction is carried out with added D2O serves to discard the direct insertion of the carbene group into the Csp2?H bond, the alternative electrophilic attack to the pyrrole ring being feasible. (Figure presented.).
Semi-Synthesis of C-Ring Cyclopropyl Analogues of Fraxinellone and Their Insecticidal Activity against Mythimna separata Walker
Dong, Qing-Miao,Tang, Jiang-Jiang,Wang, Min-Ran,Yang, Xiao-Jun
, (2020)
Fraxinellone (1) is a naturally occurring degraded limonoid isolated from Meliaceae and Rutaceae plants. As a potential natural-product-based insecticidal agent, fraxinellone has been structurally modified to improve its activity. Furan ring of fraxinellone is critical in exhibiting its insecticidal activity, but with few modifications. Herein, C-ring-modified cyclopropyl analogues were semi-synthesized by Rh(II)-catalyzed cyclopropanation. The structures of the target compounds were well characterized by NMR and HRMS. The precise three-dimensional structural information of 3a was established by X-ray crystallography. Their insecticidal activity was evaluated against Mythimna separata Walker by a leaf-dipping method. Compound 3c exhibited stronger insecticidal activity than 1 and toosendanin against M. separata with teratogenic symptoms during the different periods, implying that cyclopropanation of the furan ring could strengthen the insecticidal activity of fraxinellone.
Regioselective One-Pot Synthesis of Triptycenes via Triple-Cycloadditions of Arynes to Ynolates
Umezu, Satoshi,dos Passos Gomes, Gabriel,Yoshinaga, Tatsuro,Sakae, Mikei,Matsumoto, Kenji,Iwata, Takayuki,Alabugin, Igor,Shindo, Mitsuru
, p. 1298 - 1302 (2017)
We developed the novel one-pot synthetic method of substituted triptycenes by the reaction of ynolates and arynes. This four-step process involves three cycloadditions and electrocyclic ring opening of the strained Dewar anthracene. Each of the three related but structurally distinct classes of nucleophiles (ynolate, enolate, and anthracenolate) reacts with o-benzyne in the same predictable manner controlled by chelation and negative hyperconjugation. The resulting functionalized C3-symmetrical triptycenes hold promise in the design of functional materials.
Synthesis of Functionalized Silsesquioxane Nanomaterials by Rhodium-Catalyzed Carbene Insertion into Si?H Bonds
Franz, Annaliese K.,Jagannathan, Jake R.,Targos, Karina
supporting information, (2021/11/27)
We report carbene insertion into Si?H bonds of polyhedral oligomeric silsesquioxanes (POSS) for the synthesis of highly functionalized siloxane nanomaterials. Dirhodium(II) carboxylates catalyze insertion of aryl-diazoacetates as carbene precursors to afford POSS structures containing both ester and aryl groups as orthogonal functional handles for further derivatization of POSS materials. Four diverse and structurally varied silsesquioxane core scaffolds with one, three, or eight Si?H bonds were evaluated with diazo reactants to produce a total of 20 new POSS compounds. Novel diazo compounds containing a fluorinated octyl group and boron-dipyrromethene (BODIPY) chromophore demonstrate the use of highly functionalized substrates. Transformations of aryl(ester)-functionalized POSS compounds derived from this method are demonstrated, including ester hydrolysis and Suzuki–Miyaura cross-coupling.
All-Carbon Tetrasubstituted Olefins Synthesis from Diazo Compounds and Iodonium Ylides under Blue LED Irradiation
Zhao, Yan-Rui,Li, Lei,Xu, Guo-Yong,Xuan, Jun
supporting information, p. 506 - 511 (2021/12/08)
A route for the construction of all-carbon tetra-substituted olefins through visible-light promoted coupling of diazo compounds with iodonium ylides was developed. A wide range of all-carbon tetra-substituted olefins was obtained in moderate to good yields. The synthetic values of the current method were further approved by the synthesis of natural isolates modified alkenes and the successful transformation of final olefins into important heterocycles. (Figure presented.).
Copper-Catalyzed Oxidation of Hydrazones to Diazo Compounds Using Oxygen as the Terminal Oxidant
Liu, Wenbin,Twilton, Jack,Wei, Bo,Lee, Maizie,Hopkins, Melissa N.,Bacsa, John,Stahl, Shannon S.,Davies, Huw M. L.
, p. 2676 - 2683 (2021/03/03)
A mild method for accessing diazo compounds via aerobic oxidation of hydrazones is described. This catalytic transformation employs a Cu(OAc)2/pyridine catalyst and molecular oxygen from ambient air as the terminal oxidant, generating water as the sole byproduct and affording the desired diazo compounds within minutes at room temperature. A broad array of electronically diverse aryldiazo esters, ketones, and amides can be accessed. Pyridine dramatically enhances the rate of the reaction by solubilizing the copper catalyst and serving as the Br?nsted base in the turnover-limiting proton-coupled oxidation of hydrazone by copper(II). Insights gained from mechanistic studies led to expansion of the scope of this method to include diaryl hydrazones, delivering diaryl diazomethane derivatives, which cannot be accessed via established diazo transfer methods. The products of this method may be employed in rhodium carbene catalysis without isolation of the diazo intermediate to afford cyclopropane products in good yield with high enantioselectivity.
Visible-light-promoted selective: O -alkylation of 2-pyridones with α-aryldiazoacetates
Yang, Jingya,Wang, Ganggang,Zhou, Hongyan,Li, Zhifeng,Ma, Ben,Song, Menghui,Sun, Rongxia,Huo, Congde
supporting information, p. 394 - 398 (2021/01/29)
A visible-light-promoted O-H insertion reaction between 2-pyridones and α-aryldiazoacetates has been developed. Upon visible light irradiation, the reaction proceeds smoothly under mild and catalyst-free conditions. A wide scope of 2-pyridones and α-aryldiazoacetates are well tolerated, and various O-alkylated 2-pyridones are obtained with perfect selectivity and good functional group tolerance. A photoinduced radical process is probably responsible for the excellent selectivity. This journal is
Divergent Synthesis of Aziridine and Imidazolidine Frameworks under Blue LED Irradiation
Cheng, Xiao,Cai, Bao-Gui,Mao, Hui,Lu, Juan,Li, Lei,Wang, Kun,Xuan, Jun
supporting information, p. 4109 - 4114 (2021/05/26)
We develop a visible light-promoted divergent cycloaddition of α-diazo esters with hexahydro-1,3,5-triazines, leading to a series of aziridine and imidazolidine frameworks in average good yield, by simply changing the reaction media used. It is noteworthy that the reaction occurs under sole visible light irradiation without the need for exogenous photoredox catalysts. More significantly, a reasonable reaction mechanism was proposed on the basis of the control experiments and density functional theory calculation results.
Visible-Light-Promoted Polysubstituted Olefins Synthesis Involving Sulfur Ylides as Carbene Trapping Reagents
Ye, Cong,Cai, Bao-Gui,Lu, Juan,Cheng, Xiao,Li, Lei,Pan, Zhong-Wen,Xuan, Jun
, p. 1012 - 1022 (2021/01/09)
A blue-light-emitting diode (LED) promoted coupling of aryl diazoacetates with sulfur ylides is described. This protocol features mild conditions, good functional group tolerance, and broad substrate scope for both aryl diazoacetates with sulfur ylides. Under optimal reaction conditions, a wide range of trisubstituted olefins is obtained in moderate to good yield, which can be further transferred to other biologically important heterocycles after a two-step simple operation.
