16768-69-7Relevant academic research and scientific papers
Novel aza-BODIPY based small molecular NIR-II fluorophores for: In vivo imaging
Bai, Lei,Sun, Pengfei,Liu, Yi,Zhang, Hang,Hu, Wenbo,Zhang, Wansu,Liu, Zhipeng,Fan, Quli,Li, Lin,Huang, Wei
, p. 10920 - 10923 (2019)
The development of new NIR-II fluorophores, particularly those with facile syntheses, high fluorescence quantum yields, and stable and tunable photophysical properties, is challenging. Herein, we report a new class of small molecular NIR-II fluorophores based on aza-dipyrromethene boron difluoride (aza-BODIPY) dyes. We demonstrate promising photophysical properties of these dyes, such as large Stokes shift, superior photostability, and good fluorescence brightness as nanoparticles in aqueous solution. Because of these properties and high resolution and deep penetration NIR-II imaging ability, the aza-BODIPY based dyes show great potential as NIR-II imaging agents.
Covalent Organic Frameworks toward Diverse Photocatalytic Aerobic Oxidations
Liu, Shuyang,Tian, Miao,Bu, Xiubin,Tian, Hua,Yang, Xiaobo
supporting information, p. 7738 - 7744 (2021/05/07)
Photoactive two-dimensional covalent organic frameworks (2D-COFs) have become promising heterogenous photocatalysts in visible-light-driven organic transformations. Herein, a visible-light-driven selective aerobic oxidation of various small organic molecules by using 2D-COFs as the photocatalyst was developed. In this protocol, due to the remarkable photocatalytic capability of hydrazone-based 2D-COF-1 on molecular oxygen activation, a wide range of amides, quinolones, heterocyclic compounds, and sulfoxides were obtained with high efficiency and excellent functional group tolerance under very mild reaction conditions. Furthermore, benefiting from the inherent advantage of heterogenous photocatalysis, prominent sustainability and easy photocatalyst recyclability, a drug molecule (modafinil) and an oxidized mustard gas simulant (2-chloroethyl ethyl sulfoxide) were selectively and easily obtained in scale-up reactions. Mechanistic investigations were conducted using radical quenching experiments and in situ ESR spectroscopy, all corroborating the proposed role of 2D-COF-1 in photocatalytic cycle.
B(C6F5)3-Catalyzed Deoxygenative Reduction of Amides to Amines with Ammonia Borane
Pan, Yixiao,Luo, Zhenli,Han, Jiahong,Xu, Xin,Chen, Changjun,Zhao, Haoqiang,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
supporting information, p. 2301 - 2308 (2019/01/30)
The first B(C6F5)3-catalyzed deoxygenative reduction of amides into the corresponding amines with readily accessible and stable ammonia borane (AB) as a reducing agent under mild reaction conditions is reported. This metal-free protocol provides facile access to a wide range of structurally diverse amine products in good to excellent yields, and various functional groups including those that are reduction-sensitive were well tolerated. This new method is also applicable to chiral amide substrates without erosion of the enantiomeric purity. The role of BF3 ? OEt2 co-catalyst in this reaction is to activate the amide carbonyl group via the in situ formation of an amide-boron adduct. (Figure presented.).
Ru-Catalyzed Deoxygenative Transfer Hydrogenation of Amides to Amines with Formic Acid/Triethylamine
Pan, Yixiao,Luo, Zhenli,Xu, Xin,Zhao, Haoqiang,Han, Jiahong,Xu, Lijin,Fan, Qinghua,Xiao, Jianliang
supporting information, p. 3800 - 3806 (2019/07/12)
A ruthenium(II)-catalyzed deoxygenative transfer hydrogenation of amides to amines using HCO2H/NEt3 as the reducing agent is reported for the first time. The catalyst system consisting of [Ru(2-methylallyl)2(COD)], 1,1,1-tris(diphenylphosphinomethyl) ethane (triphos) and Bis(trifluoromethane sulfonimide) (HNTf2) performed well for deoxygenative reduction of various secondary and tertiary amides into the corresponding amines in high yields with excellent selectivities, and exhibits high tolerance toward functional groups including those that are reduction-sensitive. The choice of hydrogen source and acid co-catalyst is critical for catalysis. Mechanistic studies suggest that the reductive amination of the in situ generated alcohol and amine via borrowing hydrogen is the dominant pathway. (Figure presented.).
Method for selective reducing reaction of tertiary aryl amide and borane
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Paragraph 0085-0088, (2019/10/23)
The present invention relates to a method for a selective reducing reaction of a tertiary aryl amide and borane. A tertiary amine product is prepared by the reducing reaction of a tertiary aryl amidederivative and a cheap and easily available organoboron reagent under mild conditions under the convenient catalysis of a non-transition metal compound sodium triethylborohydride used as a catalyst for the first time. Compared with traditional methods, the method of the method generally has the advantages of wide universality of a substrate, low cost and easy availability of the catalyst, and simplicity in reaction operation. The selective reducing reaction of the tertiary aryl amide compound and the organoboron reagent under the catalysis of the transition metal catalyst is realized for the first time, and a brand new "green" reaction strategy is provided for the laboratory preparation or industrial production of tertiary arylamine products.
Sodium Triethylborohydride-Catalyzed Controlled Reduction of Unactivated Amides to Secondary or Tertiary Amines
Yao, Wubing,He, Lili,Han, Deman,Zhong, Aiguo
, (2019/11/14)
The first transition-metal-free catalytic protocol for controlled reduction of amide functions using cheap and bench-stable hydrosilanes as reducing agents has been established. By altering the hydrosilane and solvent, the new method enables the selective cleavage of unactivated C-O bonds in amides and allows the C-N bonds to selectively break via the deacylated cleavage. Overall, this novel process may offer a versatile alternative to current methodologies employing stoichiometric metal systems for the controlled reduction of carboxamides.
Sodium Triethylborohydride-Catalyzed Controlled Reduction of Unactivated Amides to Secondary or Tertiary Amines
Yao, Wubing,He, Lili,Han, Deman,Zhong, Aiguo
, p. 14627 - 14635 (2019/12/02)
The first transition-metal-free catalytic protocol for controlled reduction of amide functions using cheap and bench-stable hydrosilanes as reducing agents has been established. By altering the hydrosilane and solvent, the new method enables the selective cleavage of unactivated C-O bonds in amides and allows the C-N bonds to selectively break via the deacylated cleavage. Overall, this novel process may offer a versatile alternative to current methodologies employing stoichiometric metal systems for the controlled reduction of carboxamides.
Method for efficiently preparing tetrahydroquinoline compound, and catalyst with acid or alkaline carrier supporting Ni metal
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Paragraph 0023; 0025; 0026, (2018/11/27)
The invention relates to a method for efficiently preparing a tetrahydroquinoline compound, and a catalyst with an acid or alkaline carrier supporting Ni metal, and belongs to the field of biomass ethanol conversion. The invention also relates to an application of the co-catalyst with a metal active center and the solid acid or alkaline carrier in the synthesis of 1,2,3,4-tetrahydroquinoline, andbelongs to the technical field of biomass ethanol conversion. The catalyst consists of uniformly dispersed nickel nano particles and a nickel-aluminum (zirconium) composite oxide. The catalyst is prepared by in-situ topological transformation of nickel-containing hydrotalcite (NiAl-LDHs, NiAlZr-LDHs), and has the advantages that a strong interface interaction exists between the Ni nano particles and the carrier. When a reaction is carried out at the temperature of 125 DEG for 16 hours, and the yield of 1,2,3,4-tetrahydroquinoline by the catalysis of Ni-NiAl-LDO can reach 97%. When the reactionis carried out for 26 hours, the yield of 1,2,3,4-tetrahydroquinoline by the catalysis of Ni-NiAlZr-LDO can reach 95%.
Iridium-Catalyzed Direct Cyclization of Aromatic Amines with Diols
Minakawa, Maki,Watanabe, Kouichi,Toyoda, Satoru,Uozumi, Yasuhiro
, p. 2385 - 2389 (2018/11/23)
We developed an environmentally friendly iridium-catalyzed direct cyclization of aromatic amines with diols that generates the corresponding N-heterocyclic compounds with water as the sole by-product. Thus, under conditions of 165 °C for 18 hours, the direct cyclization of N -methylanilines with 1,3-propanediol by using an IrCl 3 catalyst with rac -BINAP as a ligand in mesitylene afforded the corresponding tetrahydroquinoline derivatives with yields ranging from 73 to 83%. Under similar reaction conditions, direct cyclization of anilines with 1,3-propanediol produced the corresponding tetrahydrobenzoquinolizine derivatives with yields ranging from 26 to 76%.
Rhenium-Loaded TiO2: A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2
Toyao, Takashi,Siddiki,Morita, Yoshitsugu,Kamachi, Takashi,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Furukawa, Shinya,Ariga, Hiroko,Asakura, Kiyotaka,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
supporting information, p. 14848 - 14859 (2017/10/27)
Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
