880158-11-2Relevant academic research and scientific papers
Bimetallic docked covalent organic frameworks with high catalytic performance towards coupling/oxidation cascade reactions
Gao, Tingjun,Gao, Yanan,Hu, Hui,Li, Yaling,Su, Xiaofang,Wu, Jifeng,Xu, Huanjun,Zeng, Chaoyuan,Zhang, Xiaosong,Zuo, Kaiming
, p. 4874 - 4882 (2022/02/19)
Covalent organic frameworks (COFs) are an emerging class of crystalline porous polymers that make these materials suitable for use as excellent scaffold in heterogeneous catalysis. Here we synthesize a layered two-dimensional (2D) COF (TADP-COF) through the condensation reaction between four-branched 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAPP) and linear 2,5-dihydroxyterephthalaldehyde (Dha) and 1,4-phthalaldehyde (PA) building blocks. Porphyrin units, imine and hydroxyl groups together with imines can provide wide coordination sites for metal docking. Using a programmed synthetic procedure, Cu(ii) ions first coordinated with the imine groups in conjunction with their adjacent hydroxyl groups, and porphyrin units and subsequently added Pd(ii) ions occupied the remaining imine sites in the space between adjacent COF layers. The bimetallic Pd(ii)/Cu(ii)@TADP-COF showed high catalytic activity in a one-pot coupling/oxidation cascade reaction in water. The high surface area, one-dimensional (1D) open channel structure and predesigned catalytic active sites of this material make it ideal candidate for use as heterogeneous catalyst in a wide range of catalytic reactions.
Purinenucleoside derivative modified in 8-position and medical use thereof
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Page/Page column 35, (2010/11/28)
The present invention provides an 8-modified purinenucleoside derivative which is useful for diseases associated with an abnormality of plasma uric acid level. An 8-modified purinenucleoside derivative represented by the following formula (I), a prodrug thereof or a pharmaceutically acceptable salt thereof, or a hydrate or solvate thereof, is useful for the prevention or treatment of gout, hyperuricemia, urinary lithiasis, hyperuricemic nephropathy or the like. In the formula, n is 1 or 2; RA is a hydrogen atom or a hydroxyl group; R1 is a hydrogen atom, a hydroxyl group, a thiol group, an amino group or a chlorine atom; ring J represents an optionally substituted 2-naphthyl group, or a group represented by the following general formula (II) wherein Y represents a single bond or a connecting group; ring Z represents an optionally substituted aryl group or heteroaryl group or the like; and R2 to R4, P1 and Q represents a halogen atom, a cyano group or the like.
Microwave-assisted Suzuki coupling reactions with an encapsulated palladium catalyst for batch and continuous-flow transformations
Baxendale, Ian R.,Griffiths-Jones, Charlotte M.,Ley, Steven V.,Tranmer, Geoffrey K.
, p. 4407 - 4416 (2008/02/07)
This article describes the design, optimisation and development of a Suzuki cross-coupling protocol mediated by an efficient palladium-en-capsulated catalyst (Pd EnCat) under microwave irradiation. The methodology has been used in both batch mode for classical library preparation and in continuous-flow applications furnishing multigram quantities of material. Described is a method that uses direct focused microwave heating whilst applying an external cooling source. This enables a lower than normal bulk temperature to be maintained throughout the reaction period leading to significant improvements in the overall yield and purity of the reaction products. Additional aspects of this novel heating protocol are discussed in relation to the prolonged lifetime and enhanced reactivity of the immobilised catalyst system.
