56309-76-3Relevant academic research and scientific papers
Ni nanoparticle-confined covalent organic polymer directed diaryl-selenides synthesis
Awasthi, Satish Kumar,Dixit, A. K.,Raghothama, S.,Yadav, Deepika
supporting information, p. 12266 - 12272 (2020/10/02)
The present work describes the preparation of a new covalent organic polymer (COP) and its application as a hetero support for diaryl selenides synthesis. A nitrogen rich COP (CGP) has been synthesized via SNAr reaction of cyanuric chloride with guanidinium hydrochloride. The successful confinement of COP with Ni nanoparticles through post-synthetic transformations (Ni?CGP) provides excellent catalytic activity for the transformation of aryl halides into diaryl selenides using elemental selenium powder. The synthetic transformations are well confirmed using various modern analytical and spectroscopic techniques which reveal high chemical and thermal durability. The N-rich framework of CGP fortifies the confinement of Ni NPs. Ni?CGP provides an efficient approach for diaryl selenides synthesis using a very cheap selenating reagent under water benign solvent conditions (DMSO?:?H2O) at room temperature with high reusability. Significantly, our work not only contributes the opportunity for developing economical and effective non-noble metal decorated COPs as heterogeneous catalysts, but also delivers an efficient approach to produce industrially important C-Se coupling products.
Selenacalix[4]dithienothiophene: Synthesis, Structure, and Complexation of a Cyclic Tetramer of Selenide-Bridging Dithienothiophene
Hasegawa, Masashi,Takahashi, Kazuhiro,Inoue, Ryota,Haga, Shiori,Mazaki, Yasuhiro
supporting information, p. 1647 - 1650 (2018/09/21)
An efficient cyclization toward a cyclic tetramer of dithienothiophene (DTT) linked by divalent selenium atoms has been developed via palladium-catalyzed coupling reaction of (nBu3Sn)2Se. X-ray analysis revealed its highly symmetrical structure had an alternate arrangement of DTT units. There are several Se???π interactions forming a supramolecular network leading to large void channel space. The cyclic tetramer possesses moderate electron-donating ability. Furthermore, the cyclic tetramer undergoes complexation with C60 in a 1:2 ratio in the solid state to give a highly symmetrical three-dimensional array of C60.
Palladium Nanoparticles Supported on Nitrogen-rich Containing Melamine-based Microporous Covalent Triazine Polymers as Efficient Heterogeneous Catalyst for C?Se Coupling Reactions
Sadhasivam, Velu,Balasaravanan, Rajendiran,Chithiraikumar, Chinnadurai,Siva, Ayyanar
, p. 3833 - 3844 (2018/07/30)
In the present work, microporous nitrogen containing covalent triazine polymers (CTPs) TATAM was synthesized from condensation of 4,4′4′′-(1,3,5-triazine-2,4,6-triyl) tribenzaldehyde (TATA) and melamine under solvothermal conditions to obtain nitrogen- rich triazine containing polymeric supported materials (TATAM). Further, palladium nanoparticles (Pd NPs) were supported on TATAM polymeric networks (Pd@TATAM). The synthesized Pd@TATAM CTPs material was thoroughly characterized by FT-IR, UV-DRS, solid state 13C-CPMAS, XPS, powder X-ray diffraction, TGA, SEM, TEM. In addition, the characterized Pd@TATAM CTPs were applied to check the catalytic application. The Pd@TATAM was shown to be an efficient and reusable heterogeneous solid catalyst for the formation of C?Se bond through coupling of aryl halide and elemental selenium, dimethyl sulfoxide as a solvent at 100 °C for about 6 h. Besides the absence of metal leaching for catalytic system, it is also observed that the catalyst can be reused for three consecutive cycles with a minimal decrease in its activity.
Microwave-assisted Cu2O-catalyzed one-pot synthesis of symmetrical diaryl selenides from elemental selenium
Zhang, Shaozhong,Karra, Kranthi,Heintz, Christina,Kleckler, Erica,Jin, Jin
supporting information, p. 4753 - 4755 (2013/08/23)
A novel and simple microwave-assisted one-pot protocol to prepare symmetrical diaryl selenides has been developed. A cross-coupling reaction between aryl iodide and elemental selenium takes place in the presence of KOH and a catalytic amount of Cu2O/NH2CH2CH 2NH2, leading to C-Se bond formation. The reactions are highly efficient with a reaction time of 1 h under microwave irradiation and yields from 50% to 90%.
Potassium selenocyanate as an efficient selenium source in C-Se cross-coupling catalyzed by copper iodide in water
Kumar, A. Vijay,Reddy, V. Prakash,Reddy, C. Suresh,Rao, K. Rama
supporting information; experimental part, p. 3978 - 3981 (2011/08/09)
An efficient and conceptually new protocol for C-Se cross coupling of potassium selenocyanate with aryl halides via copper-catalyzed cascade reaction has been developed in water. Utilizing this protocol, a variety of aryl and heteroaryl halides were reacted with potassium selenocyanate to afford the corresponding diaryl selenides in moderate to good yields.
Structural studies on diaryl selenide dihalides in solution: Molecular complex formation of substituted diphenyl selenides with bromine
Nakanishi, Waro?,Hayashi, Satoko,Kusuyama, Yoshiaki
, p. 262 - 270 (2007/10/03)
Diaryl selenides that yield molecular complexes (MC) with bromine are prepared by modulating the effective electronegativity of the selenium atom and the steric environment around the atom in diphenyl selenide (1) with various substituents at the 2-, 3- and/or 4-positions. Halogen induced 1H and 13C NMR chemical shifts of the diaryl selenides are examined. The chlorine and iodine adducts of the selenides are shown to be trigonal bipyramidal adducts (TB) and MC, respectively. In the case of bromine adducts, the structures of (3- and 4-YC6H4)2SeBr2 are demonstrated to be MC if Y is CN and NO2, contrary to the general rule: they are TB if Y is less electron-withdrawing than the ethoxycarbonyl group. The CN and NO2 groups increase the effective electronegativity of the Se atom in (3- and 4-YC6H4)2Se and do not give TB with bromine. The four chloro groups at all meta-positions in 1 are also effective for MC formation. However, 3,5-(O2N)2C6H3SeBr2Ph is TB. Ab initio MO calculations show that the structures of (3-O2NC6H4)2Se and 3,5-(O2N)2C6H3SePh are close to the C2 and C s symmetries, respectively, which reveals that the conformational change is also important when the structures of the bromine adducts are determined. The steric congestion must be more severe for TB formation than for MC formation. The structures of 2,6-Cl2C6H3- SeBr2C6H4Y-p (Y = H and Br) are MC, which shows that the steric effect of 2,6-Cl2C6H3 group is effective for MC formation. (2-MeC6H4)2SeBr2 and (2-ClC6H4)2SeBr2 are TB and MC, respectively: the electronic effect of the Cl group must play an additional role in the MC formation since the bulkiness of the Me and Cl groups are expected to be similar. The bromine adduct of (2,4,6-Me3C6H2)2Se is also concluded to be MC: the steric effect of the four Me groups at the ortho-positions is large enough to give MC with bromine. The oxidation potentials (Eox) of the diaryl selenides explain well the structures of the bromine adducts: the electronic effect is directly correlated with Eox and the importance of the steric effect has been brought into sharp relief by Eox. Results of MO calculations support the outline of the observations. The structural behavior of some halogen adducts such as 2,6-Cl2C6H3SeCl2C6H 4Y-p (TB: Y = H and Br) is also discussed in some detail.
