133709-00-9Relevant academic research and scientific papers
Photocatalytic (Het)arylation of C(sp3)-H Bonds with Carbon Nitride
Das, Saikat,Murugesan, Kathiravan,Villegas Rodríguez, Gonzalo J.,Kaur, Jaspreet,Barham, Joshua P.,Savateev, Aleksandr,Antonietti, Markus,K?nig, Burkhard
, p. 1593 - 1603 (2021/02/09)
Graphitic carbon nitride materials have attracted significant interest in recent years and found applications in diverse light-to-energy conversions such as artificial photosynthesis, CO2 reduction, or degradation of organic pollutants. However, their utilization in synthetic photocatalysis, especially in the direct functionalization of C(sp3)-H bonds, remains underexplored. Herein, we report mesoporous graphitic carbon nitride (mpg-CN) as a heterogeneous organic semiconductor photocatalyst for direct arylation of C(sp3)-H bonds in combination with nickel catalysis. Our protocol has a broad synthetic scope (>70 examples including late-stage functionalization of drugs and agrochemicals), is operationally simple, and shows high chemo- and regioselectivities. Facile separation and recycling of the mpg-CN catalyst in combination with its low preparation cost, innate photochemical stability, and low toxicity are beneficial features overcoming typical shortcomings of homogeneous photocatalysis. Detailed mechanistic investigations and kinetic studies indicate that an unprecedented energy-transfer process (EnT) from the organic semiconductor to the nickel complex is operating.
Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
Du, Chen-Xia,Huang, Zijun,Jiang, Xiaolin,Li, Yuehui,Makha, Mohamed,Wang, Fang,Zhao, Dongmei
supporting information, p. 5317 - 5324 (2020/09/17)
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element-hydrogen (E-H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium trihydroxyaryl borates exhibit high reactivity of reductive N-formylation toward a variety of amines (106 examples), including those with functional groups such as ester, olefin, hydroxyl, cyano, nitro, halogen, MeS-, ether groups, etc. The over-performance to catalyze formylation of challenging pyridyl amines affords a promising alternative method to the use of traditional formylation reagents. Mechanistic investigation supports electrostatic interactions as the key for Si/B-H activation, enabling alkali metal borates as versatile catalysts for hydroborylation, hydrosilylation, and reductive formylation/methylation of CO2.
Methyl-Selective α-Oxygenation of Tertiary Amines to Formamides by Employing Copper/Moderately Hindered Nitroxyl Radical (DMN-AZADO or 1-Me-AZADO)
Nakai, Satoru,Yatabe, Takafumi,Suzuki, Kosuke,Sasano, Yusuke,Iwabuchi, Yoshiharu,Hasegawa, Jun-ya,Mizuno, Noritaka,Yamaguchi, Kazuya
supporting information, p. 16651 - 16659 (2019/11/11)
Methyl-selective α-oxygenation of tertiary amines is a highly attractive approach for synthesizing formamides while preserving the amine substrate skeletons. Therefore, the development of efficient catalysts that can advance regioselective α-oxygenation at the N-methyl positions using molecular oxygen (O2) as the terminal oxidant is an important subject. In this study, we successfully developed a highly regioselective and efficient aerobic methyl-selective α-oxygenation of tertiary amines by employing a Cu/nitroxyl radical catalyst system. The use of moderately hindered nitroxyl radicals, such as 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) and 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO), was very important to promote the oxygenation effectively mainly because these N-oxyls have longer life-times than less hindered N-oxyls. Various types of tertiary N-methylamines were selectively converted to the corresponding formamides. A plausible reaction mechanism is also discussed on the basis of experimental evidence, together with DFT calculations. The high regioselectivity of this catalyst system stems from steric restriction of the amine-N-oxyl interactions.
Photosubstitution reaction of cyanoaromatics with aliphatic amides
Tsuji, Moriya,Higashiyama, Kimio,Yamauchi, Takayasu,Kubo, Hajime,Ohmiya, Shigeru
, p. 1027 - 1032 (2007/10/03)
Photoreaction of p- (4) and o-dicyanobenzene (6) and 4-cyanopyridine (7) with formamides (1 and 3) and 1-alkyl-2-pyrrolidone (2) produced α-aryl amides (10, 12, 13, 16, and 17). This reaction is attributable to a substitution of the carbon adjacent to the nitrogen of the amide for the cyano group in 4 and 7.
Photoinduced Nucleophilic Addition of Ammonia and Alkylamines to Aryl-Substituted Alkenes in the Presence of p-Dicyanobenzene
Yamashita, Toshiaki,Shiomori, Koichiro,Yasuda, Masahide,Kensuke, Shima
, p. 366 - 374 (2007/10/02)
The photoamination of 1,1-diphenylpropene (1a) with ammonia and some primary alkylamines in the presence of p-dicyanobenzene gave the corresponding N-substituted 2-amino-1,1-diphenylpropane (2a-e) along with the formation of 3-methyl-4,4-diphenylbutanenitrile (3a), 1,1-diphenylpropane (4a), 3,3-diphenylpropene (5), and diphenylmethane (6).In the case of 1,1-diphenylethene (1b), N-substituted 1-amino-2,2-diphenylethane (2f-h), 4,4-diphenylbutanenitrile (3b), and 1,1-diphenylethane (4b) were produced.In photoamination with t-butylamine in acetonitrile, 3a and 3b were mainly formed as a consequence of the incorporation of acetonitrile to 1a and 1b.The photoamination of 1-phenyl-3,4-dihydronaphthalene (1c) with isopropylamine or t-butylamine gave cis- and trans-N-substituted 1-phenyl-2-amino-1,2,3,4-tetrahydronaphthalenes (15 and 16) in a ratio of ca. 8:2.The mechanism of photoamination is discussed in terms of a photochemical electron transfer of 1 to p-dicyanobenzene followed by a nucleophilic addition of the amine to the cation radical of 1.
