92850-41-4Relevant academic research and scientific papers
Optimized Scalable Synthesis of Chiral Iridium Pyridyl-Phosphinite (Pyridophos) Catalysts
Müller, Marc-André,Gani?, Adnan,H?rmann, Esther,Kaiser, Stefan,Maywald, Matthias,Roseblade, Stephen J.,Schrems, Marcus G.,Schumacher, Andreas,Woodmansee, David,Pfaltz, Andreas
, (2020/12/01)
Iridium catalysts with chiral P,N ligands have greatly enhanced the scope of asymmetric olefin hydrogenation because they do not require a coordinating group near the C=C bond like Rh and Ru catalysts. Pyridophos ligands, possessing a conformationally restricted annulated pyridine framework linked to a phosphinite group, proved to be particularly effective, inducing high enantioselectivities in the hydrogenation of a remarkably broad range of substrates. Here we report the development of an efficient scalable synthesis for the two most versatile Ir-pyridophos catalysts, derived from 2-phenyl-8-hydroxy-5,6,7,8-tetrahydroquinoline or the analogue with a five-membered carbocyclic ring, respectively, by modification and optimization of the original synthetic route. The optimized route renders both catalysts readily accessible in multi-gram quantities in analytically pure form in overall yields of 26–37 %, starting from acetophenone and cyclopentanone or cyclohexanone, respectively. A major advantage of the new synthesis is the efficient and practical kinetic resolution of the late-stage pyridyl alcohol intermediates with commercial immobilized Candida antarctica lipase B, giving access to both enantiomers of these catalysts as essentially enantiopure compounds. The catalysts are obtained as crystalline solids, which are air-stable and can be stored for years at ?20 °C without notable decomposition.
Rhodium Catalyzed Asymmetric Hydrogenation of 2-Pyridine Ketones
Yang, Hailong,Huo, Ningning,Yang, Ping,Pei, Hao,Lv, Hui,Zhang, Xumu
supporting information, p. 4144 - 4147 (2015/09/15)
Catalyzed by [Rh(COD)Binapine]BF4, the asymmetric hydrogenation of 2-pyridine ketones has been achieved with excellent enantioselectivities (enantiomeric excesses up to 99%) under mild conditions. This method is suitable for various kinds of 2-pyridine ketones and their derivatives. A number of enantiomerically pure chiral 2-pyridine-aryl/alkyl alcohols were prepared through hydrogenation, which can be used directly in organic synthesis.
Design and synthesis of new chiral pyridine-phosphite ligands for the copper-catalyzed enantioselective conjugate addition of diethylzinc to acyclic enones
Xie, Yinjun,Huang, Hanmin,Mo, Weimin,Fan, Xiangqun,Shen, Zhiqiang,Shen, Zhenlu,Sun, Nan,Hu, Baoxiang,Hu, Xinquan
experimental part, p. 1425 - 1432 (2009/12/04)
A series of new chiral pyridine-phosphite ligands have been prepared from (R)-pyridyl alcohols and BINOL-derived chlorophosphite, and successfully employed in the copper-catalyzed enantioselective conjugate addition of diethylzinc to acyclic enones. Using the simple and inexpensive CuBr2 as a precursor, the enantioselective additions to various substituted acyclic enones afforded products in high yields and good enantioselectivities (up to 92% ee).
Kinetic resolution of diols and pyridyl alcohols by cu(II)(borabox)- catalyzed acylation
Mazet, Clement,Roseblade, Stephen,Koehler, Valentin,Pfaltz, Andreas
, p. 1879 - 1882 (2007/10/03)
Boron-bridged bisoxazoline (borabox) ligands have been used in the copper(II)-catalyzed benzoylation of pyridyl alcohols and 1,2-diols. Efficient kinetic resolution of 1,2-diols was achieved using both borabox and bisoxazoline (box) ligands. Borabox ligands induced high selectivities in the benzoylation of suitable pyridyl alcohols, where they outperformed bisoxazolines. In addition, highly enantioselective Cu(II)(borabox)-catalyzed benzoylation has been used for the synthesis of both enantiomers of a pyridyl alcohol.
Chemokine receptor binding heterocyclic compounds
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Page column 39, (2008/06/13)
This invention relates to a novel class of heterocyclic compounds that bind chemokine receptors, inhibiting the binding of their natural ligands thereby. These compounds result in protective effects against infection by HIV through binding to chemokine receptors, including CXCR4 and CCR5, thus inhibiting the subsequent binding by these chemokines. The present invention provides a compound of Formula I wherein, W is a nitrogen atom and Y is absent or, W is a carbon atom and Y═H; R1to R7may be the same or different and are independently selected from hydrogen or straight, branched or cyclic C1-6alkyl; R8is a substituted heterocyclic group or a substituted aromatic group Ar is an aromatic or heteroaromatic ring each optionally substituted at single or multiple, non-linking positions with electron-donating or withdrawing groups; n and n′ are independently, 0-2; X is a group of the formula: Wherein, Ring A is an optionally substituted, saturated or unsaturated 5 or 6-membered ring, and P is an optionally substituted carbon atom, an optionally substituted nitrogen atom, sulfur or oxygen atom. Ring B is an optionally substituted 5 to 7-membered ring. Ring A and Ring B in the above formula can be connected to the group W from any position via the group V, wherein V is a chemical bond, a (CH2)n″group (where n″=0-2) or a C═O group. Z is, (1) a hydrogen atom, (2) an optionally substituted C1-6alkyl group, (3) a C0-6alkyl group substituted with an optionally substituted aromatic or heterocyclic group, (4) an optionally substituted C0-6alkylamino or C3-7cycloalkylamino group, (5) an optionally substituted carbonyl group or sulfonyl. These compounds further include any pharmaceutically acceptable acid addition salts and metal complexes thereof and any stereoisomeric forms and mixtures of stereoisomeric forms thereof.
