5916-22-3Relevant academic research and scientific papers
para-Selective arylation and alkenylation of monosubstituted arenes using thianthreneS-oxide as a transient mediator
Chen, Xiao-Yue,Nie, Xiao-Xue,Wu, Yichen,Wang, Peng
, p. 5058 - 5061 (2020/05/18)
Using thianthreneS-oxide (TTSO) as a transient mediator,para-arylation and alkenylation of mono-substituted arenes have been demonstratedviaapara-selective thianthrenation/Pd-catalyzed thio-Suzuki-Miyaura coupling sequence under mild conditions. This reaction features a broad substrate scope, and functional group and heterocycle tolerance. The versatility of this approach was further demonstrated by late-stage functionalization of complex bioactive scaffolds, and direct synthesis of some pharmaceuticals, including Tetriprofen, Ibuprofen, Bifonazole, and LJ570.
Preparation method of para-substituted aryl compound
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, (2020/06/09)
The invention discloses a preparation method of a para-substituted aryl compound shown as a formula (I) which is described in the specfication. The preparation method is characterized by comprising the following step of: subjecting an aryl sulfonium salt shown as a formula (II) which is described in the specfication and boride to a coupling reaction in a solvent in an inert atmosphere under the action of alkali and a palladium catalyst to obtain the para-substituted aryl compound. According to the method, mono-substituted aromatic hydrocarbon is taken as a substrate, the aryl sulfonium salt isconstructed in situ, and the palladium catalyst catalyzes the aryl sulfonium salt constructed in situ to undergo the Suzuki-Miyaura coupling reaction, so a mono-substituted aromatic hydrocarbon para-arylation or alkenylation product is constructed quickly and efficiently. The method is mild in conditions, high in substrate universality and wide in tolerance of a heterocyclic coupling substrate.
Electrochemical Aziridination by Alkene Activation Using a Sulfamate as the Nitrogen Source
Li, Jin,Huang, Wenhao,Chen, Jingzhi,He, Lingfeng,Cheng, Xu,Li, Guigen
supporting information, p. 5695 - 5698 (2018/04/30)
The first direct aziridination of triaryl-substituted alkenes was achieved by means of an electrochemical process that could extend to multisubstituted styrenes. Specifically, hexafluoroisopropanol sulfamate was used as a nucleophilic nitrogen source. Mechanistic experiments suggest that this electrochemical process proceeds by stepwise formation of two C?N bonds through reactions between cationic carbon species and the sulfamate.
Redesign of a Pyrylium Photoredox Catalyst and Its Application to the Generation of Carbonyl Ylides
Alfonzo, Edwin,Alfonso, Felix Steven,Beeler, Aaron B.
supporting information, p. 2989 - 2992 (2017/06/07)
We report the exploration into photoredox generation of carbonyl ylides from benzylic epoxides using newly designed 4-mesityl-2,6-diphenylpyrylium tetrafluoroborate (MDPT) and 4-mesityl-2,6-di-p-tolylpyrylium tetrafluoroborate (MD(p-tolyl)PT) catalysts. These catalysts are excited at visible wavelengths, are highly robust, and exhibit some of the highest oxidation potentials reported. Their utility was demonstrated in the mild and efficient generation of carbonyl ylides from benzylic epoxides that otherwise could not be carried out by current common photoredox catalysts.
Role of sterically demanding chiral dirhodium catalysts in site-selective C-H functionalization of activated primary C-H bonds
Qin, Changming,Davies, Huw M. L.
, p. 9792 - 9796 (2014/07/22)
The influence of sterically demanding dirhodium tetracarboxylate catalysts on the site selectivity of C-H functionalization by means of rhodium carbene-induced C-H insertion is described. The established dirhodium tetraprolinate-catalyzed reactions of aryldiazoacetates cause preferential C-H functionalization of secondary C-H bonds as a result of competing steric and electronic effects. The sterically more demanding dirhodium tetrakis(triarylcyclopropanecarboxylate) catalysts, exemplified by dirhodium tetrakis[(R)-(1-(biphenyl)-2,2-diphenylcyclopropanecarboxylate)] [Rh 2(R-BPCP)4], favor C-H functionalization of activated primary C-H bonds. Highly site-selective and enantioselective C-H functionalization of a variety of simple substrates containing primary benzylic, allylic, and methoxy C-H bonds was achieved with this catalyst. The utility of this approach has been demonstrated by the late-stage primary C-H functionalization of (-)-∝-cedrene and a steroid.
Amido pincer nickel catalyzed kumada cross-coupling of aryl, heteroaryl, and vinyl chlorides
Zhang, Xue-Qi,Wang, Zhong-Xia
supporting information, p. 2081 - 2084 (2013/10/21)
Amido pincer nickel complexes {Ni(Cl)[2-P(Ph2)C 6H4NC(Ph)=NAr]} (Ar = 4-MeC6H4, 1; Ar = 4-ClC6H4, 2; Ar = 4-MeOC6H4, 3) were shown to efficiently catalyze the cross-coupling of activated, unactivated, and deactivated aryl chlorides, N-heteroaryl chlorides, 1,4-dichlorobenzene, and vinyl chlorides with aryl Grignard reagents. Georg Thieme Verlag Stuttgart, New York.
Kumada coupling of aryl, heteroaryl, and vinyl chlorides catalyzed by amido pincer nickel complexes
Liu, Ning,Wang, Zhong-Xia
experimental part, p. 10031 - 10038 (2012/02/05)
A series of amido pincer complexes of nickel were examined for their catalysis in the Kumada cross-coupling reaction. The P,N,O-pincer nickel complexes tested are active catalysts for the cross-coupling of aryl, heteroaryl, and vinyl chlorides with aryl Grignard reagents. The reactions can proceed at room temperature and tolerate functional groups in aryl chlorides with the aid of LiCl and ZnCl2 additives (Figure presented).
Nickel(0)-catalyzed cross-coupling of alkyl arenesulfonates with aryl Grignard reagents
Cho, Chul-Hee,Yun, Hee-Sung,Park, Kwangyong
, p. 3017 - 3025 (2007/10/03)
The nickel-catalyzed cross-coupling reactions of neopentyl arenesulfonates with arylmagnesium bromides, involving nucleophilic aromatic substitution of alkyloxysulfonyl groups by aryl nucleophiles, take place in high yields. Optimal efficiencies are obtained by adding 3 + 2 equiv of the Grignard reagent to a mixture of dppfNiCl2 and the sulfonate in refluxing THF. Neopentyl arenesulfonates are useful sources of the electrophilic aryl groups in these transition metal-catalyzed cross-coupling reactions. Aryl sulfonates are inappropriate due to their ambident reactivity under the reaction conditions. This new cross-coupling reaction can be used for the creative elimination of alkyloxysulfonyl groups from aromatic compounds and for the preparation of unsymmetric terphenyls and oligophenyls.
Control of regioselectivity by the lone substituent through steric and electronic effects in the nitrosoarene ene reaction of deuterium-labeled trisubstituted alkenes
Adam, Waldemar,Krebs, Oliver,Orfanopoulos, Michael,Stratakis, Manolis
, p. 8395 - 8399 (2007/10/03)
For the ene reaction of 4-nitronitrosobenzene (ARNO) with a variety of primary and secondary lone alkyl-substituted substrates, the twix/twin regioselectivity is constant at about 85:15. In contrast, for the lone tert-butyl group and for lone aryl substituents, the twix regioisomer is obtained exclusively. These regioselectivities have been rationalized in terms of steric interactions and coordination between the enophile and the substrates in the transition states of the first reaction step.
Novel reaction: Decarboxylative Bamberg-Backlung rearrangement in some α-isopropyl sulfonyl carboxylic esters
Wladislaw,Marzorati,Torres Russo,Zaim,Di Vitta
, p. 8367 - 8370 (2007/10/02)
The reaction of some isopropylsulfonyl α-mono and disubstituted esters with KOH/t-BuOH/CCl4 is reported. For the α,α-dialkyl and α-monoaryl substituted derivatives the key step of this reaction is proposed to be the decarboxylative 1,3-displacement in the chlorinated intermediates.
