877663-24-6Relevant academic research and scientific papers
Dehydrogenation of N-Heterocycles by Superoxide Ion Generated through Single-Electron Transfer
Huang, Yuan-Qiong,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
, p. 2065 - 2069 (2018/01/27)
Nitrogen-containing heteroarene motifs are found in numerous pharmaceuticals, natural products, and synthetic materials. Although several elegant methods for synthesis of these compounds through dehydrogenation of the corresponding saturated heterocycles have been reported, some of the methods are hampered by long reaction times, harsh conditions, and the need for catalysts that are not readily available. This work reports a novel method for dehydrogenation of N-heterocycles. Specifically, O2.? generated in situ acts as the oxidant for N-heterocycle substrates that are susceptible to oxidation through a hydrogen atom transfer mechanism. This method provides a general, green route to N-heteroarenes.
Palladium-catalyzed regiocontrolled domino synthesis of N-sulfonyl dihydrophenanthridines and dihydrodibenzo[c, e]azepines: Control over the formation of biaryl sultams in the intramolecular direct arylation
Laha, Joydev K.,Dayal, Neetu,Jain, Roli,Patel, Ketul
, p. 10899 - 10907 (2015/01/08)
A palladium-catalyzed domino N-benzylation/intramolecular direct arylation involving sulfonanilides and 2-bromobenzyl bromides has been developed for the first time, providing a workable access to N-sulfonyl dihydrophenanthridines in good to excellent yields. Under the optimized conditions, the formation of 5,6-dihydrophenanthridines was largely controlled over the formation of biaryl sultams containing a seven member ring. The optimized condition was found extendable to the regiocontrolled domino formation of N-sulfonyl-6,7-dihydro-5H-dibenzo[c,e]azepines over the biaryl sultam formation. Using an appropriate substrate, a biaryl sultam has been obtained exclusively.
Ultrasound-promoted intramolecular direct arylation in a capillary flow microreactor
Zhang, Lei,Geng, Mei,Teng, Peng,Zhao, Dan,Lu, Xi,Li, Jian-Xin
, p. 250 - 256 (2012/04/23)
An intramolecular direct arylation of various aryl bromides was performed using ultrasonic irradiation and a continuous flow capillary microreactor. The present procedure provided a higher functional group tolerance, ligand-free, milder reaction condition
Synthesis OF 5,6-dihydrophenanthridine (DHPA) sulfonamides and subsequent acid-catalyzed rearrangement to diaryl sulfones
Marie, Lisa,Meseroll, Neuls,McKee, James R.,Zanger, Murray
, p. 2557 - 2568 (2011/08/07)
As part of an ongoing investigation into the rearrangement of cyclic aryl aminesulfonanilides to diarylsulfones, a series of novel 5,6- dihydrophenanthridine (DHPA) sulfonamides were synthesized. Acid catalysts were used to rearrange them to DHPA arylsulfones. Taylor & Francis Group, LLC.
Catalytic direct arylation with aryl chlorides, bromides, and iodides: Intramolecular studies leading to new intermolecular reactions
Campeau, Louis-Charles,Parisien, Mathieu,Jean, Annie,Fagnou, Keith
, p. 581 - 590 (2007/10/03)
A catalyst for the intramolecular direct arylation of a broad range of simple and heterocyclic arenes with aryl iodides, bromides, and chlorides has been developed. These reactions occur in excellent yield and are highly selective. Studies with aryl iodides substrates revealed that catalyst poisoning occurs due to the accumulation of iodide in the reaction media. This can be overcome by the addition of silver salts which also permits these reactions to occur at lower temperature. The utility of the methodology is illustrated by a rapid synthesis of a carbazole natural product and by the synthesis of sterically encumbered tetra-ortho-substituted biaryls via ring-opening reactions of the direct arylation products. Mechanistic investigations have provided insight into the catalyst's mode of action and show the presence of a kinetically significant C-H bond cleavage in palladium-catalyzed direct arylation of simple arenes. Knowledge garnered from these studies has led to the development of new intermolecular arylation reactions with previously inaccessible arenes, opening the door for the development of other new direct arylation processes.
