74447-76-0Relevant academic research and scientific papers
Molecular recognition of isomeric protonated amino acid esters monitored by ESI-mass spectrometry
Liesenfeld, Andrea,Lutzen, Arne
, p. 825 - 831 (2014)
Two new 9,9'-spirobifluorene-derived crown ethers were prepared and used to recognise constitutionally isomeric amino acid derivatives. The performance of the receptors was evaluated by ESI-mass spectrometry using the isomer labelled guest method (ILGM).
Palladium-catalyzed dynamic kinetic asymmetric transformation of racemic biaryls: Axial-to-central chirality transfer
Yang, Liu,Zheng, Huayu,Luo, Lei,Nan, Jiang,Liu, Jingjing,Wang, Yaoyu,Luan, Xinjun
, p. 4876 - 4879 (2015)
The first dynamic kinetic asymmetric transformation of racemic biaryl substrates on the basis of axial-to-central chirality transfer has been realized. Chiral Pd-NHC complexes were found to catalyze the dynamic kinetic asymmetric spiroannulation of 4-(2-bromoaryl)-naphthalen-1-ols (or 2′-bromo-[1,1′-biphenyl]-4-ols) with internal alkynes, affording a series of enantioenriched spirocyclic products bearing an all-carbon quaternary stereocenter in good yields (up to 95%) with excellent enantioselectivities (up to 97% ee).
Construction of Chiral Tetraorganosilicons by Tandem Desymmetrization of Silacyclobutanes/Intermolecular Dehydrogenative Silylation
Zhang, Qing-Wei,An, Kun,Liu, Li-Chuan,Zhang, Qi,Guo, Huifang,He, Wei
, p. 1125 - 1129 (2017)
We report a method to construct chiral tetraorganosilicons by tandem silacyclobutane (SCB) desymmetrization–dehydrogenative silylations. A wide array of dibenzosiloles with stereogenic quaternary silicon centers were obtained in good yields and enantioselectivities up to 93 % ee. Chiral TMS-segphos was found to be a superior ligand in terms of reactivity and enantioselectivity.
Rhodium-Catalyzed Synthesis of Chiral Monohydrosilanes by Intramolecular C?H Functionalization of Dihydrosilanes
Ma, Wenpeng,Liu, Li-Chuan,An, Kun,He, Tao,He, Wei
supporting information, p. 4245 - 4251 (2020/12/25)
The preparation of chiral monohydrosilanes remains a rarely achieved goal. To this end a Rh-catalyzed desymmetrization of dihydrosilanes by way of intramolecular C(sp2)?H functionalization under simple and mild conditions has now been developed
Further lead optimization on Bax activators: Design, synthesis and pharmacological evaluation of 2-fluoro-fluorene derivatives for the treatment of breast cancer
Liu, Gang,Kim, Hyejin,Wang, Pingyuan,Fricke, Doerte R.,Chen, Haiying,Wang, Tianzhi,Shen, Qiang,Zhou, Jia
, (2021/04/19)
To further pursue potent Bax activators with better safety profiles for the treatment of breast cancer, structural optimization was conducted based on lead compound CYD-4-61 through several strategies, including scaffold hopping on the 2-nitro-fluorene ring, replacement of the nitro group with bioisosteres to avoid potential toxicity, and further optimization on the upper pyridine by exploring diverse alkylamine linkers as a tail or replacing the pyridine with bioisosteric heterocycles. F-containing compound 22d (GL0388) exhibited a good balance between the activity and toxicity, displaying submicromolar activities against a variety of cancer cell lines with 5.8–10.7-fold selectivity of decreased activity to MCF-10A human mammary epithelial cell line. Compound 22d dose-dependently blocked colony formation of breast cancer cells and prevented the migration and invasion of MDA-MB-231 cells. Mechanism of action studies indicate that 22d activated Bax, rendering its insertion into mitochondrial membrane, thereby leading to cytochrome c release from the mitochondria into the cytoplasm, subsequently inducing release of apoptotic biomarkers. Further in vivo efficacy studies of 22d in human breast cancer xenografts arisen from MDA-MB-231 cells demonstrated that this drug candidate significantly suppressed tumor growth, indicating the therapeutic promise of this class of compounds for the treatment of breast cancer as well as the potential for developing F-radiolabeled imaging ligands as anticancer chemical probes.
Synthesis of Dibenzosiloles through Electrocatalytic Sila-Friedel-Crafts Reaction
Han, Pan,Yin, Mengyun,Li, Haiqiong,Yi, Jundan,Jing, Linhai,Wei, Bangguo
supporting information, p. 2757 - 2761 (2021/04/16)
A novel electrocatalyzed method for the preparation of dibenzosiloles was developed through intramolecular C?H/Si?H dehydrogenative coupling strategy starting from biarylhydrosilanes. Both electro-donating and electro-withdrawing substitution groups were tolerated for this transformation, and the desired dibenzosilole products could be obtained in moderate to excellent yields. A sila-Friedel-Crafts reaction mechanism was proposed on the basis of previous literature and our controlled experiments. (Figure presented.).
Palladium-catalyzed relay C–H functionalization to construct novel hybrid-arylcyclophosphorus ligand precursors
Bai, Peng-Bo,Wang, Juan,Yang, Shang-Dong
supporting information, (2021/11/17)
A new relay C–H functionalization of di([1,1′-biphenyl]-2-yl)phosphine oxide to obtain esterified and hydroxylated products with different hypervalent iodines as oxidants under palladium catalysis is disclosed. This reaction provides a more effective and concise strategy for the synthesis of novel structural hybrid-arylcyclophosphorus ligand precursors with a wide range of substrates and good functional group tolerance.
Dephosphinylative [4 + 2] Benzannulation of Phosphinyl Ynamines: Application to the Modular Synthesis of Polycyclic Aromatic Amines
Okuda, Yasuhiro,Fujimoto, Mayo,Akashi, Haruo,Orita, Akihiro
supporting information, p. 17651 - 17666 (2021/12/13)
A series of 9-amino-10-halophenanthrenes were synthesized through a one-pot process, including dephosphinylative Sonogashira–Hagihara coupling of 2-bromobiphenyls with air-stable phosphinyl ynamines, followed by halonium-promoted [4 + 2] benzannulation of the resulting 2-(aminoethynyl)biphenyls. Nonsubstituted and methyl-substituted 2-bromobiphenyls rapidly underwent the Sonogashira–Hagihara aminoethynylation and the halogenative Friedel–Crafts benzannulation to provide the corresponding amino(halo)phenanthrenes in high yields, while electron-sufficient and -deficient substrates did slowly undergo the former and the latter to result in low yields, respectively. This protocol worked well for the syntheses of highly π-extended aminophenanthrenes and aminobenzonaphthothiophenes with different optical properties. Further application of this approach between 2,2″- and 2′,5′-dibromo-p-terphenyls with phosphinyl ynamines led to the regioselective formation of 6,13-diamino-5,12-dihalo- and 5,12-diamino-6,13-dihalo-dibenz[a,h]anthracenes via dual aminoethynylation and [4 + 2] benzannulation. The obtained analogues showed different ultraviolet–visible absorption and photoluminescence spectra with different emission quantum yields in CH2Cl2 solution and the powder state.
Selective Mechanochemical Monoarylation of Unbiased Dibromoarenes by in Situ Crystallization
Seo, Tamae,Kubota, Koji,Ito, Hajime
supporting information, p. 9884 - 9889 (2020/05/19)
Palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of liquid, unbiased dibromoarenes under mechanochemical conditions selectively afford the monoarylated products. The lower reactivity of the crystalline monoarylated products relative to the liquid starting materials should be attributed predominantly to the low diffusion efficiency of the former in the reaction mixture, which results in a selective monoarylation. The present study sheds light on a novel approach using in situ phase transitions in solids to design selective organic transformations that are difficult to achieve via conventional solution-based synthesis.
Palladium (II)–Salan Complexes as Catalysts for Suzuki–Miyaura C–C Cross-Coupling in Water and Air. Effect of the Various Bridging Units within the Diamine Moieties on the Catalytic Performance
Bunda, Szilvia,Joó, Ferenc,Kathó, ágnes,Udvardy, Antal,Voronova, Krisztina
supporting information, (2020/09/18)
Water-soluble salan ligands were synthesized by hydrogenation and subsequent sulfonation of salens (N,N’-bis(slicylidene)ethylenediamine and analogues) with various bridging units (linkers) connecting the nitrogen atoms. Pd (II) complexes were obtained in reactions of sulfosalans and [PdCl4]2?. Characterization of the ligands and complexes included extensive X-ray diffraction studies, too. The Pd (II) complexes proved highly active catalysts of the Suzuki–Miyaura reaction of aryl halides and arylboronic acid derivatives at 80 ?C in water and air. A comparative study of the Pd (II)–sulfosalan catalysts showed that the catalytic activity largely increased with increasing linker length and with increasing steric congestion around the N donor atoms of the ligands; the highest specific activity was 40,000 (mol substrate) (mol catalyst × h)?1. The substrate scope was explored with the use of the two most active catalysts, containing 1,4-butylene and 1,2-diphenylethylene linkers, respectively.
