118334-83-1Relevant articles and documents
Electrochemical decarboxylative C3 alkylation of quinoxalin-2(1: H)-ones with N -hydroxyphthalimide esters
Niu, Kaikai,Song, Lingyun,Hao, Yanke,Liu, Yuxiu,Wang, Qingmin
, p. 11673 - 11676 (2020)
We have developed a protocol for electrochemical decarboxylative C3 alkylation of a wide range of quinoxalin-2(1H)-ones under metal- and additive-free conditions. N-Hydroxyphthalimide esters derived from chain, cyclic, primary, secondary, and tertiary carboxylic acids with a broad scope proved to be suitable substrates. This operationally simple protocol performed in an undivided cell under constant-current conditions is suitable for late-stage functionalization of quinoxalin-2(1H)-ones. The reactions can even be carried out with a 3 V battery as a power source, which demonstrates that organic electrosynthesis can be accomplished without the need for specialized equipment.
Copper-Catalyzed Decarboxylative Radical Silylation of Redox-Active Aliphatic Carboxylic Acid Derivatives
Xue, Weichao,Oestreich, Martin
, p. 11649 - 11652 (2017)
A decarboxylative silylation of aliphatic N-hydroxyphthalimide (NHPI) esters using Si?B reagents as silicon pronucleophiles is reported. This C(sp3)?Si cross-coupling is catalyzed by copper(I) and follows a radical mechanism, even with exclusion of light. Both primary and secondary alkyl groups couple effectively, whereas tertiary alkyl groups are probably too sterically hindered. The functional-group tolerance is generally excellent, and α-heteroatom-substituted substrates also participate well. This enables, for example, the synthesis of α-silylated amines starting from NHPI esters derived from α-amino acids. The new method extends the still limited number of C(sp3)?Si cross-couplings of unactivated alkyl electrophiles.
Deprotonated Salicylaldehyde as Visible Light Photocatalyst
Zhuang, Yan-Jun,Qu, Jian-Ping,Kang, Yan-Biao
, p. 4386 - 4397 (2020)
Salicylaldehyde is established as an efficient visible light photocatalyst for the first time. Compared to other simple aldehyde analogies, salicylaldehyde has a unique deprotonative red-shift from 324 to 417 nm and gives rise to the remarkable increase of fluorescence quantum from 0.0368 to 0.4632, thus enabling salicylaldehyde as a visible light (>400 nm) photocatalyst. The experimental investigations suggest that the reactive radical species are generated by sensitization of the substrates by the deprotonated salicylaldehyde through an energy-transfer pathway. Consequently, the C-C cleaving alkylation reactions of N-hydroxyphthalimide esters proceed smoothly in the presence of as low as 1 mol % of salicylaldehyde under the visible-light irradiation, affording desired alkylation products with up to 99% yields. Application in visible-light induced aerobic oxidation of N-alkylpyridinium salts is also reported.
Biocompatible Photoinduced Alkylation of Dehydroalanine for the Synthesis of Unnatural α-Amino Acids
Delgado, José A. C.,Correia, José T. M.,Pissinati, Emanuele F.,Paix?o, Márcio W.
, p. 5251 - 5255 (2021)
A site-selective alkylation of dehydroalanine to access protected unnatural amino acids is described. The protocol is characterized by the wide nature of alkyl radicals employed, mild conditions, and functional group compatibility. This protocol is further extended to access peptides, late-stage functionalization of pharmaceuticals, and enantioenriched amino acids.
Catalyst-free electrochemical decarboxylative cross-coupling of: N -hydroxyphthalimide esters and N-heteroarenes towards C(sp3)-C(sp2) bond formation
Liu, Yichang,Xue, Liwei,Shi, Biyin,Bu, Faxiang,Wang, Dan,Lu, Lijun,Shi, Renyi,Lei, Aiwen
, p. 14922 - 14925 (2019)
Cheap and widely available carboxylic acids are a class of ideal substrates to construct valuable compounds. As a candidate of decarboxylative reactions, the acid-based neutral N-hydroxyphthalimide ester undergoes a reductive decarboxylative process rather than a common oxidative decarboxylative process, which is a potential transformation mode for new reactions. In this work, we developed an electrochemical C(sp3)-C(sp2) coupling of N-hydroxyphthalimide esters and N-heteroarenes without any catalysts. Remarkably, this electrochemical protocol can not only be directly realised by carboxylic acids in a one-pot fashion, but also be scaled up using a continuous-flow reactor.
Visible-Light-Induced Copper-Catalyzed Decarboxylative Coupling of Redox-Active Esters with N-Heteroarenes
Lyu, Xue-Li,Huang, Shi-Sheng,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
, p. 5728 - 5732 (2019)
Herein we report a protocol for visible-light-induced copper-catalyzed decarboxylative coupling reactions between N-heteroarenes and redox-active esters. Various N-hydroxyphthalimide esters reacted with isoquinoline, quinoline, pyridine, pyrimidine, quina
Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
Li, Jiacheng,Siang Tan, Suan,Kyne, Sara Helen,Wai Hong Chan, Philip
supporting information, p. 802 - 810 (2022/01/11)
A synthetic method that enables the Hantzsch ester-mediated Minisci-type C2-alkylation of quinolines, isoquinolines and pyridines by N-(acyloxy)phthalimide esters (NHPI) under blue LED (light emitting diode) light (456 nm) is described. Achieved under mild reaction conditions at room temperature, the metal-free synthetic protocol was shown to be applicable to primary, secondary and tertiary NHPIs to give the alkylated N-heterocyclic products in yields of 21–99%. On introducing a chiral phosphoric acid, an asymmetric version of the reaction was also realised and provided product enantiomeric excess (ee) values of 53–99%. The reaction mechanism was delineated to involve excitation of an electron-donor acceptor (EDA) complex, formed from weak electrostatic interactions between the Hantzsch ester and NHPI, which generates the posited radical species of the redox active ester that undergoes addition to the N-heterocycle.
Visible Light-Driven Decarboxylative Alkylation of Aldehydes via Electron Donor–Acceptor Complexes of Active Esters
Cai, Yi-Ping,Nie, Fang-Yuan,Song, Qin-Hua
supporting information, p. 1262 - 1271 (2022/01/27)
There are some synthesis methods from widely available aldehydes to the corresponding ketones, however, they involved in multistep reactions with Grignard’s reagents or transition metal catalysts. In this paper, we have developed photocatalyst-free and visible light-driven decarboxylative alkylation of pyridinaldehydes. The photochemical reactions are initiated via photoinduced single electron transfer from triethylamine to N-hydroxyphthalimide esters in electron donor–acceptor complexes. This photochemical method can achieve to translate 15 pyridinaldehydes and 11 2-quinolinaldehydes to the corresponding ketones. Furthermore, this strategy can also achieve two other transformations, disulfanes to aryl sulfides and a styrene sulfone to the alkyl-substituted alkene.
Access to functionalized luminescent Pt(ii) complexes by photoredox-catalyzed Minisci alkylation of 6-aryl-2,2′-bipyridines
Hagui, Wided,Cordier, Marie,Boixel, Julien,Soulé, Jean-Fran?ois
supporting information, p. 1038 - 1041 (2021/02/06)
Photoredox-mediated C-H bond alkylation of 6-aryl-2,2′-bipyridines withN-(acyloxy)phthalimides is reported. The reaction exhibits excellent functional group tolerance, including chiral aliphatic groups. The influence of the incorporatedC6′-alkyl group on
