81386-30-3Relevant academic research and scientific papers
Potassium Poly(Heptazine Imide): Transition Metal-Free Solid-State Triplet Sensitizer in Cascade Energy Transfer and [3+2]-cycloadditions
Antonietti, Markus,Guldi, Dirk M.,Hussain, Tanveer,Karton, Amir,Markushyna, Yevheniia,Mazzanti, Stefano,Oschatz, Martin,Sánchez Vadillo, José Manuel,Savateev, Aleksandr,Strauss, Volker,Tarakina, Nadezda V.,Tyutyunnik, Alexander P.,Walczak, Ralf,ten Brummelhuis, Katharina
, p. 15061 - 15068 (2020/06/17)
Polymeric carbon nitride materials have been used in numerous light-to-energy conversion applications ranging from photocatalysis to optoelectronics. For a new application and modelling, we first refined the crystal structure of potassium poly(heptazine imide) (K-PHI)—a benchmark carbon nitride material in photocatalysis—by means of X-ray powder diffraction and transmission electron microscopy. Using the crystal structure of K-PHI, periodic DFT calculations were performed to calculate the density-of-states (DOS) and localize intra band states (IBS). IBS were found to be responsible for the enhanced K-PHI absorption in the near IR region, to serve as electron traps, and to be useful in energy transfer reactions. Once excited with visible light, carbon nitrides, in addition to the direct recombination, can also undergo singlet–triplet intersystem crossing. We utilized the K-PHI centered triplet excited states to trigger a cascade of energy transfer reactions and, in turn, to sensitize, for example, singlet oxygen (1O2) as a starting point to synthesis up to 25 different N-rich heterocycles.
Copper-Catalyzed Trifluoromethylation of Alkyl Bromides
Kornfilt, David J.P.,Macmillan, David W.C.
supporting information, p. 6853 - 6858 (2019/05/10)
Copper oxidative addition into organohalides is a challenging two-electron process. In contrast, formal oxidative addition of copper to C sp2 carbon-bromine bonds can be accomplished by employing latent silyl radicals under photoredox conditions. This novel paradigm for copper oxidative addition has now been applied to a Cu-catalyzed cross-coupling of C sp3-bromides. Specifically, a copper/photoredox dual catalytic system for the coupling of alkyl bromides with trifluoromethyl groups is presented. This operationally simple and robust protocol successfully converts a variety of alkyl, allyl, benzyl, and heterobenzyl bromides into the corresponding alkyl trifluoromethanes.
One-Pot Synthesis of 3,5-Disubstituted 1,2,4-Oxadiazoles Using Catalytic System NaOH?DMSO
Pankrat’eva,Sharonova,Tarasenko,Baikov,Kofanov
, p. 1250 - 1255 (2018/10/24)
One-pot convenient process was developed for the production of 3,5-disubstituted 1,2,4-oxadiazoles by reaction of amidoximes with anhydrides or acyl chlorides in a system NaOH?DMSO. The reaction proceeds at room temperature with high yields.
Cobalt(III)-Catalyzed Oxadiazole-Directed C-H Activation for the Synthesis of 1-Aminoisoquinolines
Yang, Fan,Yu, Jiaojiao,Liu, Yun,Zhu, Jin
supporting information, p. 2885 - 2888 (2017/06/07)
Aromatic heterocycles have been identified as effective directing groups (DGs) in C-H functionalization but can be retained as undesired bulky substituents in the final products. Herein, we report a Co(III)-catalyzed 1-aminoisoquinoline synthesis strategy based on oxadiazole-directed aromatic C-H coupling with alkynes and a subsequent redox-neutral C-N cyclization reaction. This labile N-O bond-based protocol has allowed the toleration of a broad range of functional groups.
The first one-pot ambient-temperature synthesis of 1,2,4-oxadiazoles from amidoximes and carboxylic acid esters
Baykov, Sergey,Sharonova, Tatyana,Shetnev, Anton,Rozhkov, Sergey,Kalinin, Stanislav,Smirnov, Alexey V.
, p. 945 - 951 (2017/01/25)
The first one-pot room-temperature protocol for the synthesis of 3,5-disubstituted-1,2,4-oxadiazoles via the condensation between amidoximes and carboxylic acid esters in superbase medium MOH/DMSO is reported. A broad spectrum of alkyl, aryl and hetaryl amidoximes and esters was examined. This reaction route provides convenient access to 1,2,4-oxadiazoles, which is highly desirable because in the light of this privileged scaffold is recognized as an important core in the design of novel therapeutic agents and high-tech materials.
Preparation, structure, and versatile reactivity of pseudocyclic benziodoxole triflate, new hypervalent iodine reagent
Yoshimura, Akira,Nguyen, Khiem C.,Klasen, Scott C.,Saito, Akio,Nemykin, Victor N.,Zhdankin, Viktor V.
supporting information, p. 7835 - 7838 (2015/05/13)
A new pseudocyclic triflate derivative of benziodoxole (IBA-OTf) was prepared and characterized by X-ray analysis. This highly electrophilic reagent readily reacts with various organic substrates to give the corresponding products in good yields. Furthermore, IBA-OTf can be used as a catalyst with m-chloroperoxybenzoic acid as the terminal oxidant. This journal is
A novel, one-pot, three-component synthesis of 1,2,4-oxadiazoles under microwave irradiation and solvent-free conditions
Adib, Mehdi,Mahdavi, Mohammad,Mahmoodi, Niusha,Pirelahi, Hooshang,Bijanzadeh, Hamid Reza
, p. 1765 - 1767 (2008/02/04)
A novel synthesis of 3,5-disubstituted 1,2,4-oxadiazoles is described from a one-pot, three-component reaction between nitriles, hydroxylamine, and Meldrum's acids under microwave irradiation and solvent-free conditions in good to excellent yields. Georg
Preparation of 3,5-disubstituted 1,2,4-oxadiazoles by reactions of nitrilium salts with amide oximes
Moustafa, Ahmed H.
, p. 837 - 840 (2007/10/03)
The reaction of N-alkyl- and N-arylnitrilium salts 1a,d,g,j with the amide oximes 2a-c furnished the new iminium salts 3a-k (76-93%). On heating, compounds 3a-c cyclized to salts, which were transformed with base to the 3,5-disubstituted 1,2,4-oxadiazoles 4a-c in good yields (ca. 80%).
Palladium-catalyzed N-arylation of O-methylamidoximes
Anbazhagan, Mariappan,Stephens, Chad E,Boykin, David W
, p. 4221 - 4224 (2007/10/03)
Pd-catalyzed coupling of O-methylbenzamidoximes gave N-aryl O-methylbenzamidoximes using aryl halides with electron attracting or moderate electron donating groups. Under the same conditions, benzamidoxime failed to undergo coupling and O-acetylbenzamidoxime underwent cyclization to form the corresponding [1,2,4]oxadiazole.
Synthesis of 3,5-disubstituted-1,2,4-oxadiazoles using tetrabutylammonium fluoride as a mild and efficient catalyst
Gangloff, Anthony R.,Litvak, Joane,Shelton, Emma J.,Sperandio, David,Wang, Vivian R.,Rice, Kenneth D.
, p. 1441 - 1443 (2007/10/03)
Tetrabutylammonium fluoride (TBAF) was found to be a mild and efficient catalyst for the synthesis of 3,5-disubstituted-1,2,4-oxadiazoles. Using 0.1 - 1.0 equivalents of TBAF in THF for 1 - 24 h at room temperature, alkanoyl- and aroyloxyamidines were converted in high yield to the corresponding 3,5-disubstituted-1,2,4-oxadiazoles. A variety of R and R′ substituents were investigated.
