An efficient photocatalytic
decarboxylative 3-position alkylation
of coumarins by using alkyl N-hydroxyphthalimide
esters as alkylation reagents has been developed. A variety of NHP
esters derived from aliphatic carboxylic acids (primary, secondary,
and tertiary) has been proved to be tolerated for this decarboxylation
process, affording a broad scope of 3-alkylated coumarin derivatives
in moderate to excellent yields. This protocol was highlighted by
its mild conditions, readily available starting materials, operational
simplicity, and wide functional group tolerance.
The flexible transparent electromagnetic interference (EMI) shielding materials in visual windows is essential for the innovation of optoelectronic devices. Herein, we demonstrate the fabrication of the flexible EMI shielding films...
A photo-triggered self-catalyzed fluoroalkylation/cyclization of quinazolinones containing unactivated alkenes with various fluoroalkyl bromides has been developed.
Electromagnetic absorption and electromagnetic interference (EMI) shielding materials, especially absorption-based EMI shielding materials, are urgently desired to eliminate increasingly serious electromagnetic radiation pollution. MXenes exhibit great promising to realize excellent...
A novel visible‐light‐driven decarboxylative coupling of alkyl N‐hydroxyphthalimide esters (NHP esters) with quinoxalin‐2(1H)‐ones has been developed. This C(sp2)−C(sp3) bond‐forming transformation exhibits excellent substrate generality with respect to both the coupling partners. Of note, a series of 3‐primary alkyl‐substituted quinoxalin‐2(1H)‐ones that were difficult to synthesize by previous methods could be obtained in moderate to excellent yields. Additionally, the mild conditions, easy availability of substrates, wide functional group tolerance and operational simplicity make this protocol practical in the synthesis of 3‐alkylated quinoxalin‐2(1H)‐ones.
Electromagnetic interference (EMI) shielding materials, especially ones with excellent shielding effectiveness (SE), high optical transmittance, long‐term stability as well as high uniformity, are urgently desired to meet the requirements of many applications. Herein, an extremely transparent, stable and uniform silver nanowire (Ag NW)–poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) composite film as an EMI shielding material is prepared, which possess excellent shielding capability to both small signal and high power microwaves (HPM). The composite film exhibits SE of 30.5 dB in the frequency range of 1–12 GHz (small signal) and simultaneously has an optical transmittance of 91.0%. The SE continuously increases to 41.4 dB, while the optical transmittance still maintains at 81.1%. The composite film is very uniform, and its SE is almost unchanged even when exposed in air for a year. The SE of this composite film under the excitation of HPM is also thoroughly investigated. The HPM SE is much larger than that of small signal. As the power density of HPM is increased, the SE firstly remains unchanged, then continuously increases, and finally saturates. The SE exceeds 50 dB with the excitation power density of 40 W. More interestingly, the SE is saturated at a fixed HPM power density.
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