precise control of the oxidation pathways so that directing groups can be either preserved or cleaved. We found that N-phenoxyacetamides could undergo ortho-arylation reactions with or without an external oxidant, yielding products with different oxidation states, notably the rare bis-arylated phenols. Notably, a unique rhodacycle intermediate was isolated, characterized by X-ray crystallography, and
Highly efficient AgNO<sub>3</sub>
-catalyzed approach to 2-(benzo[<i>d</i>
]azol-2-yl)phenols from salicylaldehydes with 2-aminothiophenol, 2-aminophenol and benzene-1,2-diamine
derivatives in good to excellent yields (63–98%) is described. The reaction proceeds via condensation/intramolecular nucleophilic addition/oxidation process between substituted salicylaldehydes and 2‐aminothiophenol, 2‐aminophenol or benzene‐1,2‐diamine under mild reaction conditions. Notably, this reaction utilizes cheap AgNO3 as a readily available and low‐cost benign oxidant at low catalyst loadings with
描述了一种新的,便捷有效的AgNO 3催化策略,用于制备2-(苯并[ d ] azol-2-基)苯酚衍生物,产率高至优异(63-98%)。反应在温和的反应条件下通过取代的水杨醛与2-氨基硫酚,2-氨基酚或苯1,2-二胺之间的缩合/分子内亲核加成/氧化过程进行。值得注意的是,该反应利用廉价的AgNO 3作为易于获得的低成本良性氧化剂,催化剂负载低,具有出色的官能团耐受性。
A Highly Selective Pyrophosphate Sensor Based on ESIPT Turn-On in Water
作者:Wei-Hua Chen、Yu Xing、Yi Pang
DOI:10.1021/ol200054w
日期:2011.3.18
Pyrophosphate (PPi) is a biologically important target. A binuclear system 3•2Zn is found to selectively recognize PPi, leading to a ratiometric fluorescentsensor at pH 7.4 in water. The binding event triggered a large fluorescence response (∼100 nm bathochromic shift) by turning on the excited state intramolecular proton transfer (ESIPT). Detection of PPi released from a PCR experiment indicated
PHOTOPROTECTIVE/COSMETIC COMPOSITIONS COMPRISING A LIPOSOLUBLE, PHOTOSTABLE AND UV-PHOTOPROTECTING BENZ-x-AZOLE-SUBSTITUTED SILANE OR SILOXANE
申请人:——
公开号:US20010053856A1
公开(公告)日:2001-12-20
The invention refers to new liposoluble and photostable silicon-bearing derivatives of benz-x-azole having an excellent absorption power in the UV radiation spectrum. The invention also refers to compositions, particularly cosmetic ones, containing these new derivatives as well as the use of these derivatives as sunscreens effective in the UV radiation spectrum.
NIR-emitting styryl dyes with large Stokes’ shifts for imaging application: From cellular plasma membrane, mitochondria to zebrafish neuromast
作者:Dipendra Dahal、Krishna R. Ojha、Sabita Pokhrel、Sailaja Paruchuri、Michael Konopka、Qin Liu、Yi Pang
DOI:10.1016/j.dyepig.2021.109629
日期:2021.10
Near-infrared (NIR) emitting probes with very largeStokes' shifts play a crucial role in bioimaging applications, as the optical signals in this region exhibit high signal to background ratio and allow deeper tissue penetration. Herein we illustrate NIR-emitting probe 2 with very largeStokes' shifts (Δλ ≈ 260–272 nm) by integrating the excited-state intramolecular proton transfer (ESIPT) unit 2-