6702-58-5Relevant articles and documents
Ultraviolet-light-induced aerobic oxidation of benzylic C(sp3)-H of alkylarenes under catalyst- and additive-free conditions
Zhou, Jiacheng,Li, Meichao,Li, Tianci,Li, Chunmei,Hu, Xinquan,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu
, (2021/02/01)
A mild and efficient system has been discovered for the synthesis of α-aryl carbonyl compounds via oxidation of benzylic C–H to C[dbnd]O bonds. This ultraviolet-light-mediated oxygenation reaction exhibited excellent substrate scope including various xanthenes, thioxanthenes and 9, 10-dihydroacridines and afforded the corresponding ketones with good to excellent yields under catalyst- and additive-free conditions at room temperature.
A Green Nanopalladium-Supported Catalyst for the Microwave-Assisted Direct Synthesis of Xanthones
Diez, Alejandra S.,Gerbino, Darío C.,Mendioroz, Pamela,Steingruber, H. Sebastián
supporting information, p. 619 - 628 (2020/02/13)
We report an efficient, selective, rapid and eco-friendly protocol for the one-step synthesis of a small xanthone library via an intermolecular catalytic coupling from readily available salicylaldehydes and 1,2-dihaloarenes under ligand-free conditions. To achieve this advantageous direct annulation, we used a novel recoverable palladium nanocatalyst supported on a green biochar under microwave irradiation. Unlike other existing palladium-based approaches, our synthetic strategy showed a greater operational simplicity, drastic reduction in reaction times, and an excellent tolerance to diverse functional groups. The reaction proceeds in very good yields and with high regioselectivity. The novel heterogeneous catalyst can be recycled and reused up to four times without significant loss of activity.
Visible-light induced enhancement in the multi-catalytic activity of sulfated carbon dots for aerobic carbon-carbon bond formation
Sarma, Daisy,Majumdar, Biju,Sarma, Tridib K.
, p. 6717 - 6726 (2019/12/26)
The development of carbonaceous materials as metal-free catalysts integrating different types of catalysis in a single system represents a significant advance in cascade/tandem organic synthesis. Zero-dimensional carbon dots with tuneable optical properties and easily modifiable surface functionalities can be harnessed as a carbocatalyst for merging photooxidation and acid-catalyzed reactions in one pot. Herein, we explore carbon dots decorated with hydrogen sulfate groups as a photocatalyst for the dehydrogenative cross-coupling of xanthenes with ketones, arenes and 1,3-dicarbonyl compounds that showed high efficiency and selectivity under visible-light irradiation. The sulphated carbon dots demonstrate dual catalytic properties, wherein they induced the rapid photooxidation of xanthenes in the presence of molecular oxygen to form a hydroperoxy intermediate followed by coupling of nucleophiles catalysed by the acidic surface functional groups. The methodology represents an operationally simple pathway for the generation of C-C coupling products in a short reaction time with wide substrate scopes under mild conditions. The catalyst is easily separable and can be reused over multiple cycles with good efficiency.
