36330-85-5Relevant articles and documents
Phospholipid bicelles that align with their normals parallel to the magnetic field
Tan, Chibing,Fung,Cho, Gyoujin
, p. 11827 - 11832 (2002)
We have recently reported phospholipid bicelles (bilayered micelles) that have positive anisotropy of the magnetic susceptibility and align with their normals parallel to an external magnetic field [J. Am. Chem. Soc. 2001, 123, 1537]. Improvements have been made via the synthesis of a new phospholipid, 1-dodecanoyl-2-(4-(4-biphenyl)butanoyl)-sn-glycero-3-phosphocholine (DBBPC). Bicelles can be formed by mixing DBBPC with a short-chain phospholipid, 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) in a ratio between 5.1:1 and 6.5:1 in an aqueous medium. The 31P NMR spectra clearly show that these bicelles align with their principal axes parallel to the magnetic field within a wide temperature range. The 31P chemical shifts indicate that the conformation of the polar headgroup in these bicelles may be different from that in common bicelles. The phase behavior of a mixture of DBBPC/DHPC with 6:1 mole ratio was investigated in the temperature range of 10-75 °C using 31P, 2H, and 23Na NMR. At lower temperatures (10-54 °C), the system is dominated by the bicellar phase. At higher temperatures (54-75 °C), isotropic micelles are formed and coexist with the bicelles. The partial alignment of maltotriose in the DBBPC/ DHPC system was studied at three temperatures, and the 1H-13C dipolar coupling constants are compared with those obtained for two other bicelle solutions.
Nickel- and Palladium-Catalyzed Cross-Coupling of Stibines with Organic Halides: Site-Selective Sequential Reactions with Polyhalogenated Arenes
Ghaderi, Arash,Kambe, Nobuaki,Le, Liyuan,Lu, Hao,Qiu, Renhua,Tang, Ting,Tong, Zhou,Wong, Wai-Yeung,Xu, Zhi,Yin, Shuang-Feng,Zeng, Dishu,Zhang, Dejiang,Zhang, Zhao
, p. 854 - 867 (2022/01/19)
Herein, we disclose a general and efficient method for the synthesis of Sb-aryl and Sb-alkyl stibines by the nickel-catalyzed cross-coupling of halostibines with organic halides. The synthesized Sb-aryl stibines couple with aryl halides to give biaryls efficiently via palladium catalysis. Sequential reactions of stibines with polyhalogenated arenes bearing active C–I/C–Br sites and inactive C–Cl sites successfully proceeded, resulting in the formation of a variety of complex molecules with good site selectivity. Drugs such as diflunisal and fenbufen, as well as a fenofibrate derivative, were synthesized on gram scales in good yields, together with the high recovery of chlorostibine. Furthermore, catalytic mechanisms are proposed based on the results of control experiments.
Pd Nanoparticles Embedded Into MOF-808: Synthesis, Structural Characteristics, and Catalyst Properties for the Suzuki–Miyaura Coupling Reaction
Li, Tang,Pang, Wan,Wang, Jie,Zhang, Xiaoli,Zhao, Zesheng
, (2021/07/31)
Abstract: A heterogeneous single-site catalyst Pd@MOF-808 was successfully synthesized by water-based, green synthesis procedure. The catalytic experiments exhibited the Pd@MOF-808 promoted efficiently the Suzuki–Miyaura coupling reaction without the assistance of organic phosphine ligands at atmospheric pressure conditions. The catalyst also could be applied in the gram-scale synthesis of industrially anti-inflanmatory analgestic Fenbufen. Graphic Abstract: [Figure not available: see fulltext.]
A Convoluted Polyvinylpyridine-Palladium Catalyst for Suzuki-Miyaura Coupling and C?H Arylation
Ohno, Aya,Sato, Takuma,Mase, Toshiaki,Uozumi, Yasuhiro,Yamada, Yoichi M. A.
supporting information, p. 4687 - 4698 (2020/09/07)
The development of highly active and reusable supported catalysts for Suzuki-Miyaura coupling and catalytic C?H arylation is important for fundamental and applied chemistry, with these reactions being used to produce medical compounds and functional materials. Herein, we found that a mesoporous composite made of a linear poly(4-vinylpyridine) and tetrachloropalladate acted as a dual-mode catalyst for a variety of cross-coupling reactions, with both Pd nanoparticles and a Pd complex catalyst being observed under different conditions. The polyvinylpyridine-palladium composite 1 was readily prepared via the molecular convolution of poly(4-vinylpyridine) and sodium tetrachloropalladate to provide a hardly soluble polymer-metal composite. The Suzuki-Miyaura coupling and the C?H arylation of aryl chlorides and bromides with arylboronic acids, thiophenes, furans, benzene, and anisole proceeded in the presence of 0.004 mol% (40 mol ppm) to 1 mol% Pd of 1 to afford the corresponding coupling products in high yields. Furthermore, the catalyst was reused without an appreciable loss of activity. Pharmaceutical compounds and functional materials were synthesized via the coupling reactions. N2 gas adsorption/desorption analysis indicated that the catalyst had a mesoporous nature, which played a crucial role in the catalysis. In the Suzuki-Miyaura couplings, in situ generated palladium nanoparticles in the polymer matrix were catalytically active, while a polymeric Pd(II) complex was crucial in the C?H arylations. These catalytic species were investigated via XAFS, XPS, far-infrared absorption, and Raman spectroscopies, as well as DFT calculations. (Figure presented.).
