20541-48-4Relevant academic research and scientific papers
Selenium-linked liquid crystal dimers for twist-bend nematogens
Arakawa, Yuki,Tsuji, Hideto
, (2019)
The recently discovered twist-bend nematic (NTB) phase has become an intensively studied topic in supramolecular chemistry and condensed matter science. Herein, a new molecular design for twist-bend nematogens employing the selenoether (C–Se–C) linkage, instead of the conventional methylene or ether linkages, is introduced. We synthesized CBSenSeCB dimers, consisting of two cyanobiphenyl (CB) units connected by two selenoether linkers sandwiching an odd-numbered alkylene spacer (n = 3, 5, 7, and 9) and revealed their phase transitions and mesomorphism. CBSenSeCB (n = 5, 7, and 9) can potentially form mesophases; notably, CBSe7SeCB formed the NTB phase from the conventional uniaxial nematic phase, which was cooled to below room temperature. The structure of the all-trans model of CBSe7SeCB, optimized by the density functional theory, suggests that the molecular bend angle between the para axes of the cyanobiphenyl moieties is ～90°, which is more bent than those of previously reported twist-bend nematogens. Such a keen curvature is ascribed to the small C–Se–C angle of ～101°. In addition, the molecular bend angles of the twist-bend dimers, including the present and previously reported ones, correlate linearly with their phase-transition temperatures. The present study paves the way for the molecular design of new twist-bend nematic liquid crystals based on chalcogen linkages.
Blue light-promoted radical sulfoximido-chalcogenization of aliphatic and aromatic alkenes
Chen, Hongyi,Chen, Li,He, Ze,Zeng, Qingle
supporting information, p. 2624 - 2627 (2021/04/21)
A transition metal-free synthesis ofN-(arylthio/seleno)ethyl sulfoxidminesviablue light-promoted radical sulfoximido-chalcogenization of aliphatic and aromatic alkenes was developed. The sulfoximidation process demonstrated high chemoselectivity and allowed a broad substrate scope, completing the sulfoximido-chalcogenization of alkenes in good yields.
Highly selective radical isothiocyano-chalcogenization of alkenes with NH4SCN in water
He, Ze,Kang, Xiaokang,Xu, Chao,Zeng, Qingle
supporting information, p. 7544 - 7548 (2021/10/12)
In the presence of catalytic amounts of molecular iodine and stoichiometric potassium persulfate, a green, highly chemoselective, regioselective and cis-selective radical isothiocyano-chalcogenization of alkenes with NH4SCN in water is disclosed. This three component reaction features high selectivities, an environmentally benign process, mild conditions, high yields, excellent functional-group tolerance, and broad substrate scope. The resulting products can be further transformed into other molecules with structural similarities of these compounds to bioactive analogs.
FeCl3-catalyzed three-component aryl-selenylation of alkenes
Xu, Chao,He, Ze,Yang, Hongqin,Chen, Hongyi,Zeng, Qingle
, (2021/06/07)
FeCl3-catalyzed three-component aryl-selenylation of alkenes with good to excellent yields has been disclosed. This method is characterized by synthesis of complicated products in a single-step reaction, simple operation and readily available commercially reagents. Finally, a reasonable mechanism of FeCl3-catalyzed aryl-selenylation is proposed.
Visible-light-driven radical 1,3-addition of selenosulfonates to vinyldiazo compounds
Li, Weiyu,Zhou, Lei
supporting information, p. 6652 - 6658 (2021/09/10)
Herein, we report a visible-light-driven radical 1,3-selenosulfonylation of vinyldiazo compounds with selenosulfonates, providing various γ-seleno allylic sulfones in good yields. This photochemical reaction was carried out at room temperature in an open flask using ethyl acetate as the solvent without any photocatalysts or additives. The control experiments corroborated that the 1,3-addition proceeded via a radical-chain propagation process. The synthetic applications of the resulting products were demonstrated by deselenization, reduction, bromination and allylation.
Synthesis of Seleno Oxindoles via Electrochemical Cyclization of N-arylacrylamides with Diorganyl Diselenides
Wang, Xin-Yu,Zhong, Yuan-Fang,Mo, Zu-Yu,Wu, Shi-Hong,Xu, Yan-Li,Tang, Hai-Tao,Pan, Ying-Ming
, p. 208 - 214 (2020/12/04)
The tandem cyclization of acrylamide with diselenides facilitated by electrochemical oxidation was successfully developed. This strategy provided an environmentally friendly method for the construction of C?Se bond. A series of seleno oxindoles with pharmacological activity were obtained by using this well-designed tandem cyclization strategy. The in vitro antitumor activity of the compounds was also screened through MTT assay. Results showed that the seleno oxindoles exhibited better antitumor activity than other oxindole derivatives. (Figure presented.).
Enhancing the Potential of Miniature-Scale DNA-Compatible Radical Reactions via an Electron Donor-Acceptor Complex and a Reversible Adsorption to Solid Support Strategy
Lin, Bizhen,Lu, Weiwei,Chen, Zhen-Yu,Zhang, Yue,Duan, Yin-Zhe,Lu, Xiaojie,Yan, Ming,Zhang, Xue-Jing
supporting information, p. 7381 - 7385 (2021/10/12)
DNA-encoded library (DEL) technology is a powerful tool in the discovery of bioactive probe molecules and drug leads. Mostly, the success in DEL technology stems from the molecular diversity of the chemical libraries. However, the construction of DELs has been restricted by the idiosyncratic needs and the required low concentration (～1 mM or less) of the library intermediate. Here, we report visible-light-promoted on-DNA radical coupling reactions via an electron donor-acceptor (EDA) complex and a reversible adsorption to solid support (RASS) strategy. This protocol provides a unique solution to the challenges of increasing the reactivity of highly diluted DNA substrates and reducing the residues of heavy metals from photocatalysts. A series of on-DNA indole sulfone and selenide derivatives were obtained with good to quantitative conversions. It is anticipated that these mild-condition on-DNA radical reactions will significantly improve the chemical diversity of DELs and find widespread utility to DEL construction.
Rhodium-Catalyzed Enantioselective Hydroselenation of Heterobicyclic Alkenes
Li, Sifeng,Yang, Qingjing,Bian, Zhaoxiang,Wang, Jun
supporting information, p. 2781 - 2785 (2020/03/30)
A highly efficient Rh(I)/(S)-xyl-Binap catalytic system is developed for the asymmetric hydroselenation of various nonpolar olefins with diselenides. Under these mild reaction conditions, a wide range of heterobicyclic alkenes give selenol-incorporated adducts in excellent enantioselectivities (up to 97%) along with high yields (up to 96%) by overcoming self-promoted racemic hydroselenation. The strategy is also applied for kinetic resolution of unsymmetric oxabenzonorbornadiene.
Continuous Electrochemical Synthesis of Iso-Coumarin Derivatives from o-(1-Alkynyl) Benzoates under Metal- and Oxidant-Free
Lin, Xinxin,Fang, Zheng,Zeng, Cuilian,Zhu, Chenlong,Pang, Xinyan,Liu, Chengkou,He, Wei,Duan, Jindian,Qin, Ning,Guo, Kai
supporting information, p. 13738 - 13742 (2020/10/02)
A non-oxidant and metal-free strategy for synthesizing iso-coumarin by using a continuous electrochemical microreactor to initiate an oxidative cyclization reaction of o-(1-alkynyl) benzoate and radicals. This efficient and clean continuous electrosynthesis method not only avoids the complicated gas protection operation and production of by-products in the batch processes, but also help to overcome the difficulty that batch metal catalysis and electrocatalysis are difficult to scale up, and has the potential for pilot-scale experiment.
Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides
Li, Fuhai,Wang, Dan,Chen, Hongyi,He, Ze,Zhou, Lihong,Zeng, Qingle
supporting information, p. 13029 - 13032 (2020/11/07)
A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72-94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94-99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts. This journal is
