860818-47-9Relevant articles and documents
Palladium-on-Carbon-Catalyzed Coupling of Nitroarenes with Phenol: Biaryl Ether Synthesis and Evidence of an Oxidative-Addition-Promoted Mechanism
Begum, Tahshina,Mondal, Manoj,Borpuzari, Manash Protim,Kar, Rahul,Gogoi, Pradip K.,Bora, Utpal
supporting information, p. 3244 - 3248 (2017/06/21)
Nucleophilic substitution in nitroarenes to form biaryl ethers is of fundamental importance in organic synthesis. Under non-catalytic conditions, this can occur if highly activated nitroarenes are used or if the nucleophile is activated by a strong stoichiometric base. We established a new method involving the use of a ligand-free palladium-on-carbon (Pd/C) catalyst for the cross-coupling of activated nitroarenes with relatively non-nucleophilic phenol derivatives, including naphthol, in the absence of harsh bases. Control experiments, hot filtration, the three-phase test, and inductively coupled plasma atomic emission spectroscopy analysis revealed that the catalysis proceeded through an usual oxidative addition step of the nitroarene to Pd/C, which resulted in the release of active palladium particles having extremely high catalytic activity. DFT calculations revealed the origin of the selectivity of the activated nitroarenes.
Steps towards a practical synthesis of macrocyclic bisbenzylisoquinolines
Al-Hiari, Yusuf M.,Bennett, Stephen J.,Cox, Brian,Davies, Robert J.,Khalaf, Abedawn I.,Waigh, Roger D.,Worsley, Alan J.
, p. 647 - 659 (2007/10/03)
There are more than 400-reported bisbenzylisoquinoline alkaloids, many with interesting biological activity, but the reported syntheses are long and low yielding. As a result, there have been no systematic attempts at exploitation of the potential therapeutic applications. The concept of a sulfur 'stitch', restricting the conformational freedom of intermediates in the synthesis, will potentially allow analogues of the natural products to be prepared using relatively efficient routes. The synthesis of intermediate sulfur heterocycles is reported, based on 2,8-dimethylphenoxathiin, leading via 2,8-bis(bromomethyl) phenoxathiin-10,10-dioxide to a synthesis of 3,4,8,9-tetrahydro-13-oxa-6-thia-2, 10-diazapentacene, a key potential intermediate on the route to a variety of macrocyclic bisbenzylisoquinolines.
