- Visible-light-induced regioselective alkylation of coumarins via decarboxylative coupling with N-hydroxyphthalimide esters
-
An efficient photocatalytic decarboxylative 3-position alkylation of coumarins by using alkyl N-hydroxyphthalimide esters as alkylation reagents has been developed. A variety of NHP esters derived from aliphatic carboxylic acids (primary, secondary, and tertiary) has been proved to be tolerated for this decarboxylation process, affording a broad scope of 3-alkylated coumarin derivatives in moderate to excellent yields. This protocol was highlighted by its mild conditions, readily available starting materials, operational simplicity, and wide functional group tolerance.
- Jin, Can,Yan, Zhiyang,Sun, Bin,Yang, Jin
-
-
Read Online
- Visible-Light-Triggered Decarboxylative Alkylation of 8-Acylaminoquinoline with N -Hydroxyphthalimide Ester
-
A facile protocol for visible-light-induced decarboxylative radical coupling of NHP esters with 8-aminoquinoline amides is reported, affording a highly efficient approach to synthesize a variety of 2-alkylated or 2,4-dialkylated 8-aminoquinoline derivativ
- Aisha, Aertuke,Jin, Can,Li, Deyu,Sun, Bin,Zhu, Rui,Zhuang, Xiaohui
-
-
Read Online
- Visible Light-Induced Regioselective Decarboxylative Alkylation of the C(sp2)?H Bonds of Non-Aromatic Heterocycles
-
With sunlight or blue LEDs irradiation, regioselective decarboxylative alkylation of various non-aromatic heterocycles has been realized via C(sp3)-centered radical C(sp2)?C(sp3) bond formation under oxidant-free condition
- Liu, Lixin,Pan, Neng,Sheng, Wei,Su, Lebin,Liu, Long,Dong, Jianyu,Zhou, Yongbo,Yin, Shuang-Feng
-
-
Read Online
- Photoredox Decarboxylative C(sp3)-N Coupling of α-Diazoacetates with Alkyl N-Hydroxyphthalimide Esters for Diversified Synthesis of Functionalized N-Alkyl Hydrazones
-
Herein we report a metal-free photocatalytic coupling reaction for the synthesis of structurally and functionally diverse N-alkyl hydrazones from α-diazoacetates and N-alkyl hydroxyphthalimide esters. By employing Rose Bengal as a photocatalyst with yellow LEDs irradiation, over 60 N-alkyl hydrazones were synthesized. Fluorescence quenching analysis and deuterium incorporation experiments reveal that Hantzsch ester serves as both an electron donor and proton source for the reaction. This strategy offers a simple retrosynthetic disconnection for conventionally inaccessible C(sp3)-rich N-alkyl hydrazones.
- Chan, Chun-Ming,Xing, Qi,Chow, Yip-Chi,Hung, Sing-Fung,Yu, Wing-Yiu
-
-
Read Online
- Catalyst-free Decarboxylation and Decarboxylative Giese Additions of Alkyl Carboxylates through Photoactivation of Electron Donor-Acceptor Complex
-
We report herein a catalyst-free method to perform decarboxylative conjugated addition and hydrodecarboxylation of aliphatic N-(acyloxy)phthalimides (redox active esters, RAEs) through photoactivation of electron-donor-acceptor (EDA) complex with Hantzsch ester (HE) in N,N-dimethylacetamide (DMA) solution. The reactions present a green method to decarboxylatively construct carbon-carbon bond and to perform hydrodecarboxylation with broad substrate scope and functional group tolerance under mild blue light irradiation condition without recourse of popularly used photoredox catalysts. (Figure presented.).
- Zheng, Chao,Wang, Guang-Zu,Shang, Rui
-
-
Read Online
- Minisci-Type Alkylation of N-Heteroarenes by N-(Acyloxy)phthalimide Esters Mediated by a Hantzsch Ester and Blue LED Light
-
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.
- Kyne, Sara Helen,Li, Jiacheng,Siang Tan, Suan,Wai Hong Chan, Philip
-
supporting information
(2022/01/11)
-
- Electroreductive Cross-Coupling of Trifluoromethyl Alkenes and Redox Active Esters for the Synthesis of Gem-Difluoroalkenes
-
An electroreductive access to gem-difluoroalkenes has been developed through the decarboxylative/defluorinative coupling of N-hydroxyphtalimides esters and α-trifluoromethyl alkenes. The electrolysis is performed under very simple reaction conditions in a
- Claraz, Aurélie,Allain, Clémence,Masson, Géraldine
-
supporting information
(2021/11/17)
-
- tert-Butyl Nitrite as a Twofold Hydrogen Abstractor for Dehydrogenative Coupling of Aldehydes with N-Hydroxyimides
-
A synthetically practical transition metal/catalyst/halogen-free dehydrogenative coupling of aldehydes with N-hydroxyimides promoted solely by tert-butyl nitrite under mild conditions was developed. tert-Butyl nitrite generates two radicals (tBuO and NO) and thus works as a twofold hydrogen abstractor. A diverse array of N-hydroxyimide esters were prepared from either aliphatic or aromatic aldehydes. Benzoyl-substituted aldehydes such as 2-oxo-2-phenylacetaldehyde are also suitable.
- Dai, Peng-Fei,Wang, Yi-Ping,Qu, Jian-Ping,Kang, Yan-Biao
-
supporting information
p. 9360 - 9364
(2021/12/09)
-
- Substrate for synthesizing beta-Se amino acid as well as preparation method and application of substrate
-
The invention discloses a substrate for synthesizing beta-Se amino acid as well as a preparation method and application of the substrate, and the beta-Se amino acid is almost seldom synthesized by a method except selenocysteine at present. A substrate (namely a formula (I)) for synthesizing beta-Se amino acid is autonomously designed, and different beta-Se amino acids can be obtained only by changing a free radical precursor generated by photoreaction by using a general intermediate (namely the formula (I)) which is newly designed in the invention, so that divergent synthesis of the beta-Se amino acids is realized. According to the method for synthesizing the beta-Se amino acid, synthesis can be simply and efficiently achieved, good functional group compatibility can be achieved, the yield is generally high, and the application range of natural chemical connection is further expanded.
- -
-
Paragraph 0070-0077
(2021/08/14)
-
- Nickel-Mediated Photoreductive Cross Coupling of Carboxylic Acid Derivatives for Ketone Synthesis**
-
A simple visible light photochemical, nickel-catalyzed synthesis of ketones from carboxylic acid-derived precursors is presented. Hantzsch ester (HE) functions as a cheap, green and strong photoreductant to facilitate radical generation and also engages in the Ni-catalytic cycle to restore the reactive species. With this dual role, HE allows for the coupling of a large variety of radicals (1°,2°, benzylic, α-oxy & α-amino) with aroyl and alkanoyl moieties, a new feature in reactions of this type. With both precursors deriving from abundant carboxylic acids, this protocol is a welcome addition to the organic chemistry toolbox. The reaction proceeds under mild conditions without the need for toxic metal reagents or bases and shows a wide scope, including pharmaceuticals and complex molecular architectures.
- Brauer, Jan,Quraishi, Elisabeth,Kammer, Lisa Marie,Opatz, Till
-
supporting information
p. 18168 - 18174
(2021/11/30)
-
- Access to functionalized luminescent Pt(ii) complexes by photoredox-catalyzed Minisci alkylation of 6-aryl-2,2′-bipyridines
-
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
- Hagui, Wided,Cordier, Marie,Boixel, Julien,Soulé, Jean-Fran?ois
-
supporting information
p. 1038 - 1041
(2021/02/06)
-
- Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes
-
The addition of alkyl fragments to aliphatic aldehydes is a highly desirable transformation for fragment couplings, yet existing methods come with operational challenges related to the basicity and instability of the nucleophilic reagents commonly employed. We report herein that nickel catalysis using a readily available bioxazoline (BiOx) ligand can catalyze the reductive coupling of redox-active esters with aliphatic aldehydes using zinc metal as the reducing agent to deliver silyl-protected secondary alcohols. This protocol is operationally simple, proceeds under mild conditions, and tolerates a variety of functional groups. Initial mechanistic studies suggest a radical chain pathway. Additionally, alkyl tosylates and epoxides are suitable alkyl precursors to this transformation providing a versatile suite of catalytic reactions for the functionalization of aliphatic aldehydes.
- Xiao, Jichao,Li, Zhenning,Montgomery, John
-
supporting information
p. 21234 - 21240
(2021/12/27)
-
- Phosphoric Acid Mediated Light-Induced Minisci C?H Alkylation of N-Heteroarenes
-
Herein, we report an environmentally-friendly light-induced Minisci alkylation of N-heteroarenes with a broad substrate scope using diphenyl phosphate as catalyst under metal- and photocatalyst-free conditions. The radical precursor redox-active esters (R
- Jin, Songyang,Geng, Xinxin,Li, Yujun,Zheng, Ke
-
supporting information
p. 969 - 972
(2021/02/01)
-
- Synthesis of 2-alkyl-chroman-4-onesviacascade alkylation-dechlorination of 3-chlorochromones
-
An efficient and mild synthetic approach for 2-alkyl-substituted chroman-4-onesviazinc-mediated cascade decarboxylative β-alkylation and dechlorination of 3-chlorochromones was developed. This transformation employed commercially available starting materials and was performed under mild conditions without heat, visible light, peroxide or heavy metals. Moreover, various alkyl NHPI esters with functional groups and differently substituted 3-chlorochromones were tolerated, affording the targeted products with moderate to excellent yields. This protocol could be utilized to construct a diverse library of 2-substituted chroman-4-one derivatives, which could be useful in the discovery of lead compounds for drug discovery in the future.
- He, Qian,Li, Shunyao,Yang, Chunhao,Zhang, Lanfei,Zhang, Xiaofei
-
supporting information
p. 5348 - 5352
(2021/06/28)
-
- Biocompatible Photoinduced Alkylation of Dehydroalanine for the Synthesis of Unnatural α-Amino Acids
-
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.
- Delgado, José A. C.,Correia, José T. M.,Pissinati, Emanuele F.,Paix?o, Márcio W.
-
supporting information
p. 5251 - 5255
(2021/07/20)
-
- Photodecarboxylative Amination of Redox-Active Esters with Diazirines
-
Diazirines have been recently demonstrated to serve as electrophilic amination reagents that afford diaziridines, versatile heterocycles that are readily transformed into amines, hydrazines, and nitrogen-containing heterocycles. Here, we report the photodecarboxylative amination of redox-active esters with diazirines using inexpensive photoactivators under mild conditions with an enhanced scope for primary substrates. The stability of diazirines to blue light is demonstrated, paving the way for further research into other photochemical amination methods with these unique heterocycles.
- Maharaj, Vishala,Chandrachud, Preeti P.,Che, Wen,Wojtas, Lukasz,Lopchuk, Justin M.
-
supporting information
p. 8838 - 8842
(2021/11/24)
-
- Visible-Light-Mediated Alkylation of Thiophenols via Electron Donor-Acceptor Complexes Formed between Two Reactants
-
A metal-free, photocatalyst-free, photochemical system was developed for the direct alkylation of thiophenols via electron donor-acceptor (EDA) complexes (KEDA = 145 M-1) between two reactants, N-hydroxyphthalimide esters as acceptors and thiophenol anions as donors, in the presence of a tertiary amine. The EDA complexes in the reaction system have a broad range of visible-light absorption (400-650 nm) and can trigger the reaction effectively under sunlight.
- Cai, Yi-Ping,Nie, Fang-Yuan,Song, Qin-Hua
-
p. 12419 - 12426
(2021/09/02)
-
- Photoinduced Decarboxylative Phosphorothiolation of N-Hydroxyphthalimide Esters
-
A visible-light-induced protocol for the synthesis of phosphorothioates is developed by employing the Ir-catalyzed decarboxylative phosphorothiolation of N-hydroxyphthalimide esters. This novel synthesis method utilizes carboxylic acids as raw material, which is stable, cheap, and commercially available. Scope studies show that this reaction has good compatibility of functional groups. Notably, both the synthesis of steric hindrance phosphorothioates and the later modification of some bioactive compounds are successfully achieved.
- Guo, Yu,Luo, Ying,Mu, Shiqiang,Xu, Jian,Song, Qiuling
-
supporting information
p. 6729 - 6734
(2021/09/11)
-
- Photocatalytic Decarboxylative Coupling of Aliphatic N-hydroxyphthalimide Esters with Polyfluoroaryl Nucleophiles
-
Polyfluoroarenes are an important class of compounds in medical and material chemistry. The synthesis of alkylated polyfluoroarenes remains challenging. Here we describe a decarboxylative coupling reaction of N-hydroxyphthalimide esters of aliphatic carboxylic acids with polyfluoroaryl zinc reagents (Zn-ArF) via synergetic photoredox and copper catalysis. This method readily converts primary and secondary alkyl carboxylic acids into the corresponding polyfluoroaryl compounds, which could have a wide range of F-content (2F-5F) and variable F-substitution patterns on the aryl groups. Broad scope and good functional group compatibility were achieved, including on substrates derived from natural products and pharmaceuticals. Mechanistic study revealed that a [Cu-(ArF)2] species could be responsible for the transfer of polyfluoroaryl groups to the alkyl radicals.
- Hu, Xile,Lavrencic, Lara,Mao, Runze,Yi, Xiangli
-
supporting information
p. 23557 - 23563
(2021/09/30)
-
- Activation of Chromium Catalysts by Photoexcited Hantzsch Ester for Decarboxylative Allylation of Aldehydes with Butadiene
-
Metallaphotocatalysis often needs light-absorbing metal-polypyridyl complexes, semiconductors, or organic dyes, which can modify the oxidation state of metal catalysts. Here, we first report that photoexcitation of Hantzsch ester can directly activate chromium reagents through a single-electron transfer process. The synthetic application was demonstrated through a photoredox decarboxylative allylation of aldehydes with feedstock butadiene without exogenous photocatalysts, metallic reductants, or additives.
- Lin, Shuangjie,Chen, Yuqing,Yan, Huaipu,Liu, Yonghong,Sun, Yuchen,Hao, Erjun,Shi, Caizhe,Zhang, Dandan,Zhu, Nan,Shi, Lei
-
supporting information
p. 8077 - 8081
(2021/10/20)
-
- Visible-light-promoted radical alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester: Synthesis of oxazolines
-
An efficient photocatalytic alkylation/cyclization of allylic amide with N-hydroxyphthalimide ester has been developed. The transformation is taken advantage of alkyl radicals to attack allylic amide with the assist of inexpensive rose bengal as photocatalyst to prepare a series of alkyl substituted oxazolines in moderate to excellent yields. High regioselectivity, operational safety, mild conditions and excellent substrate generality give this protocol broad application prospects.
- Ding, Hao,Huang, Panyi,Jin, Can,Su, Weike,Sun, Bin,Yan, Zhiyang,Zhao, Haiyun
-
supporting information
(2021/10/29)
-
- An organophotoredox-catalyzed redox-neutral cascade involving: N -(acyloxy)phthalimides and allenamides: Synthesis of indoles
-
An organophotoredox-catalyzed radical cascade of allenamides and alkyl N-(acyloxy)phthalimides for the synthesis of indoles is documented. The method features mild and robust reaction conditions, and exhibits broad scope. The tandem process enriches the l
- Das, Sanju,Azim, Aznur,Hota, Sudhir Kumar,Panda, Satya Prakash,Murarka, Sandip,De Sarkar, Suman
-
supporting information
p. 13130 - 13133
(2021/12/16)
-
- Method for synthesis of beta-S amino acid
-
The invention discloses application of methyl(R)-2-(tert-butyl)-3-formyl-2, 3-thiazoline-4-methyl formate (I) in preparation of beta-S amino acid (II). According to the invention, the raw materials are simple and easily available, and a universal intermed
- -
-
Paragraph 0080-0085; 0087
(2020/04/17)
-
- Catalyst-Free Decarboxylation of Carboxylic Acids and Deoxygenation of Alcohols by Electro-Induced Radical Formation
-
Electro-induced reduction of redox active esters and N-phthalimidoyl oxalates derived from naturally abundant carboxylic acids and alcohols provides a sustainable and inexpensive approach to radical formation via undivided electrochemical cells. The resulting radicals are trapped by an electron-poor olefin or hydrogen atom source to furnish the Giese reaction or reductive decarboxylation products, respectively. A broad range of carboxylic acid (1°, 2°, and 3°) and alcohol (2° and 3°) derivatives are applicable in this catalyst-free reaction, which tolerated a diverse range of functional groups. This method features simple operation, is a sustainable platform, and has broad application.
- Chen, Xiaoping,Luo, Xiaosheng,Peng, Xiao,Guo, Jiaojiao,Zai, Jiantao,Wang, Ping
-
supporting information
p. 3226 - 3230
(2020/02/27)
-
- Vinyl Sulfonium Salts as the Radical Acceptor for Metal-Free Decarboxylative Alkenylation
-
Vinyl sulfonium salts typically act as an electrophilic Michael acceptor, thus initiating many tandem cyclization reactions. Herein, we disclosed the novel reactivity of vinyl sulfonium salts as a radical acceptor. Using redox-active ester as an alkyl rad
- Zhang, Yu-Lan,Yang, Lei,Wu, Jie,Zhu, Chunyin,Wang, Peng
-
supporting information
p. 7768 - 7772
(2020/10/09)
-
- Making Copper Photocatalysis Even More Robust and Economic: Photoredox Catalysis with [CuII(dmp)2Cl]Cl
-
The CuII complex [CuII(dmp)2Cl]Cl (dmp = 2,9-dimethyl-1,10-phenanthroline) is evaluated as an oxidation stable precursor for visible-light-mediated CuI-photoredox catalysis, being efficient and considerable more cost-effective compared to previously established copper(I) photocatalysts. Its performance and efficiency are demonstrated within a broad scope of atom transfer radical addition (ATRA) reactions, allowing the 1,2-difunctionalization of alkenes, as well as for decarboxylative coupling and an Appel reaction. Moreover, the utility of the complex is shown by various gram-scale functionalizations of styrene, thus suggesting [CuII(dmp)2Cl]Cl to be a low-priced alternative precatalyst for processes run on scale. Furthermore, this study provides UV/Vis evidence on the mechanism for the visible light activation of CuII complexes.
- Engl, Sebastian,Reiser, Oliver
-
supporting information
p. 1523 - 1533
(2019/07/31)
-
- Deprotonated Salicylaldehyde as Visible Light Photocatalyst
-
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.
- Zhuang, Yan-Jun,Qu, Jian-Ping,Kang, Yan-Biao
-
p. 4386 - 4397
(2020/03/05)
-
- Decarboxylative Thiolation of Redox-Active Esters to Thioesters by Merging Photoredox and Copper Catalysis
-
Thioesters and related thiols are critically important to biological systems and also widely employed in the synthesis of pharmaceutically important molecules and polymeric materials. However, known synthetic methods often suffer from the disadvantage of
- Cao, Tianpeng,Liao, Saihu,Nie, Xingliang,Xu, Ruting,Xu, Tianxiao,Yang, Mingcheng
-
supporting information
p. 3692 - 3696
(2020/04/21)
-
- Sodium Dithionite-Mediated Decarboxylative Sulfonylation: Facile Access to Tertiary Sulfones
-
A straightforward multicomponent decarboxylative cross coupling of redox-active esters (N-hydroxyphthalimide ester), sodium dithionite, and electrophiles was established to construct sterically bulky sulfones. The inorganic salt sodium dithionite not only served as the sulfur dioxide source, but also acted as an efficient radical initiator for the decarboxylation. Notably, diverse naturally abundant carboxylic acids and artificially prepared carboxyl-containing drugs with multiple heteroatoms and sensitive functional groups successfully underwent this decarboxylative sulfonylation to provide sterically bulky tertiary sulfones. Mechanistic studies further demonstrated that decarboxylation was the rate-determining step and occurred via a single-electron transfer (SET) process with the assistance of sodium dithionite.
- Chen, Shihao,Jiang, Xuefeng,Li, Yaping,Wang, Ming
-
supporting information
p. 8907 - 8911
(2020/04/22)
-
- Copper-catalysed photoinduced decarboxylative alkynylation: a combined experimental and computational study
-
Redox-active esters (RAEs) as alkyl radical precursors have demonstrated great advantages for C-C bond formation. A decarboxylative cross-coupling method is described to afford substituted alkynes from various carboxylic acids using copper catalysts CuCl and Cu(acac)2. The photoexcitation of copper acetylides with electron-rich NEt3as a ligand provides a general strategy to generate a range of alkyl radicals from RAEs of carboxylic acids, which can be readily coupled with a variety of aromatic alkynes. The scope of this cross-coupling reaction can be further expanded to aliphatic alkynes and alkynyl silanes using a catalytic amount of preformed copper-phenylacetylide. In addition, DFT calculations revealed the favorable reaction pathway and that the bidentate acetylacetonate ligand of the copper intermediate plays an important role in inhibiting the homo-coupling of the alkyne.
- Liang, Yong,Lu, Shuo,Mao, Yu,Ni, Shengyang,Pan, Yi,Wang, Yi,Yu, Lei,Zhao, Wenxuan
-
p. 4939 - 4947
(2020/06/09)
-
- Tandem Photoredox and Copper-Catalyzed Decarboxylative C(sp3)-N Coupling of Anilines and Imines Using an Organic Photocatalyst
-
An organic photoredox catalyst, 4CzIPN, was used in combination with a copper catalyst, CuCl, to effect decarboxylative C(sp3)-N coupling. The coupling worked with both anilines and imines as nitrogen sources and could be used to prepare a variety of alkyl amines from readily available alkyl carboxylic acids.
- Barzanò, Guido,Mao, Runze,Garreau, Marion,Waser, Jerome,Hu, Xile
-
supporting information
p. 5412 - 5416
(2020/07/14)
-
- Metal-Free Regioselective Alkylation of Imidazo[1,2- a ]pyridines with N -Hydroxyphthalimide Esters under Organic Photoredox Catalysis
-
A visible-light-induced direct C-H alkylation of imidazo[1,2- a ]pyridines has been developed. It proceeds at room temperature by employing inexpensive Eosin Y as a photocatalyst and alkyl N -hydroxyphthalimide (NHP) esters as alkylation reagents. A varie
- Jin, Can,Sun, Bin,Xu, Min,Xu, Tengwei,Yang, Jin,Zhang, Liang,Zhu, Rui
-
supporting information
p. 363 - 368
(2020/02/27)
-
- Stereoselective and Divergent Construction of β-Thiolated/Selenolated Amino Acids via Photoredox-Catalyzed Asymmetric Giese Reaction
-
Sulfur and selenium occupy a distinguished position in biology owing to their redox activities, high nucleophilicity, and acyl transfer capabilities. Thiolated/selenolated amino acids, including cysteine, selenocysteine, and their derivatives, play critic
- Chen, Huan,Wang, Ping,Wang, Siyao,Yin, Hongli,Zhang, Qiang,Zheng, Mengjie,Zhou, Qingqing
-
supporting information
p. 14201 - 14209
(2020/09/16)
-
- Electrochemical decarboxylative C3 alkylation of quinoxalin-2(1: H)-ones with N -hydroxyphthalimide esters
-
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.
- Niu, Kaikai,Song, Lingyun,Hao, Yanke,Liu, Yuxiu,Wang, Qingmin
-
supporting information
p. 11673 - 11676
(2020/10/20)
-
- Organophotoredox-Catalyzed Formation of Alkyl-Aryl and -Alkyl C-S/Se Bonds from Coupling of Redox-Active Esters with Thio/Selenosulfonates
-
A mild organophotoredox synthetic protocol for forming a Csp3-S/Se bond by reacting widespread redox-active esters with thio/selenosulfonates has been developed. The power of the synthetic manifold is fueled by an unprecedented broad substrate scope and wide functional group tolerance.
- Dong, Yue,Ji, Peng,Zhang, Yueteng,Wang, Changqing,Meng, Xiang,Wang, Wei
-
supporting information
p. 9562 - 9567
(2021/01/09)
-
- Decarboxylative Amination: Diazirines as Single and Double Electrophilic Nitrogen Transfer Reagents
-
The ubiquity of nitrogen-containing small molecules in medicine necessitates the continued search for improved methods for C-N bond formation. Electrophilic amination often requires a disparate toolkit of reagents whose selection depends on the specific structure and functionality of the substrate to be aminated. Further, many of these reagents are challenging to handle, engage in undesired side reactions, and function only within a narrow scope. Here we report the use of diazirines as practical reagents for the decarboxylative amination of simple and complex redox-active esters. The diaziridines thus produced are readily diversifiable to amines, hydrazines, and nitrogen-containing heterocycles in one step. The reaction has also been applied in fluorous phase synthesis with a perfluorinated diazirine.
- Chandrachud, Preeti P.,Wojtas, Lukasz,Lopchuk, Justin M.
-
supporting information
p. 21743 - 21750
(2021/01/11)
-
- Histidine-Specific Peptide Modification via Visible-Light-Promoted C-H Alkylation
-
Histidine (His) carries a unique heteroaromatic imidazole side chain and plays irreplaceable functional roles in peptides and proteins. Existing strategies for site-selective histidine modification predominantly rely on the N-substitution reactions of the moderately nucleophilic imidazole group, which inherently suffers from the interferences from lysine and cysteine residues. Chemoselective modification of histidine remains one of the most difficult challenges in peptide chemistry. Herein, we report peptide modification via radical-mediated chemoselective C-H alkylation of histidine using C4-alkyl-1,4-dihydropyridine (DHP) reagents under visible-light-promoted conditions. The method exploits the electrophilic reactivity of the imidazole ring via a Minisci-type reaction pathway. This method exhibits an exceptionally broad scope for both peptides and DHP alkylation reagents. Its utility has been demonstrated in a series of important peptide drugs, complex natural products, and a small protein. Distinct from N-substitution reactions, the unsubstituted nitrogen groups of the modified imidazole ring are conserved in the C-H alkylated products.
- Chen, Xiaoping,Ye, Farong,Luo, Xiaosheng,Liu, Xueyi,Zhao, Jie,Wang, Siyao,Zhou, Qingqing,Chen, Gong,Wang, Ping
-
supporting information
p. 18230 - 18237
(2019/11/14)
-
- Ni-Catalyzed β-Alkylation of Cyclopropanol-Derived Homoenolates
-
Metal homoenolates are valuable synthetic intermediates which provide access to β-functionalized ketones. In this report, we disclose a Ni-catalyzed β-alkylation reaction of cyclopropanol-derived homoenolates using redox-active N-hydroxyphthalimide (NHPI) esters as the alkylating reagents. The reaction is compatible with 1°, 2°, and 3° NHPI esters. Mechanistic studies imply radical activation of the NHPI ester and 2e β-carbon elimination occurring on the cyclopropanol.
- Mills, L. Reginald,Zhou, Cuihan,Fung, Emily,Rousseaux, Sophie A. L.
-
supporting information
p. 8805 - 8809
(2019/11/03)
-
- Photoredox-catalyzed decarboxylative alkylation/cyclization of alkynylphosphine oxides: a metal- and oxidant-free method for accessing benzo[b]phosphole oxides
-
By photoredox-catalysis, alkylation/aryl C-H cyclization of readily available alkynylphosphine oxides towards benzo[b]phospholes has been realized under metal- and oxidant-free conditions at room temperature. This reaction readily incorporates various functionalized alkyl groups into the benzo[b]phosphole skeletons, representing a mild and versatile tool for the preparation of valuable phosphole compounds.
- Liu, Lixin,Dong, Jianyu,Yan, Yani,Yin, Shuang-Feng,Han, Li-Biao,Zhou, Yongbo
-
supporting information
p. 233 - 236
(2019/01/04)
-
- Visible-Light-Induced Copper-Catalyzed Decarboxylative Coupling of Redox-Active Esters with N-Heteroarenes
-
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
- Lyu, Xue-Li,Huang, Shi-Sheng,Song, Hong-Jian,Liu, Yu-Xiu,Wang, Qing-Min
-
supporting information
p. 5728 - 5732
(2019/08/01)
-
- Construction of C(sp2)?C(sp3) Bond between Quinoxalin-2(1H)-ones and N-Hydroxyphthalimide Esters via Photocatalytic Decarboxylative Coupling
-
A novel visible-light-driven decarboxylative coupling of alkyl N-hydroxyphthalimide esters (NHP esters) with quinoxalin-2(1H)-ones has been developed. This C(sp2)?C(sp3) bond-forming transformation exhibits excellent substrate generality with respect to both the coupling partners. Of note, a series of 3-primary alkyl-substituted quinoxalin-2(1H)-ones that were difficult to synthesize by previous methods could be obtained in moderate to excellent yields. Additionally, the mild conditions, easy availability of substrates, wide functional group tolerance and operational simplicity make this protocol practical in the synthesis of 3-alkylated quinoxalin-2(1H)-ones.
- Yan, Zhiyang,Sun, Bin,Zhang, Xun,Zhuang, Xiaohui,Yang, Jin,Su, Weike,Jin, Can
-
p. 3344 - 3349
(2019/09/06)
-
- Nickel-catalyzed electrochemical reductive decarboxylative coupling of: N -hydroxyphthalimide esters with quinoxalinones
-
Herein the first example of electrochemically enabled, NiCl2-catalyzed reductive decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with quinoxalinones is reported. A range of primary, secondary, tertiary aliphatic carboxylic acids and amino acid-derived esters were tolerated well. This decarboxylative coupling allows access to structurally diverse 3-alkylated quinoxalinones in up to 91% yields.
- Lian, Fei,Xu, Kun,Meng, Wei,Zhang, Haonan,Tan, Zhoumei,Zeng, Chengchu
-
supporting information
p. 14685 - 14688
(2019/12/11)
-
- Catalyst-free electrochemical decarboxylative cross-coupling of: N -hydroxyphthalimide esters and N-heteroarenes towards C(sp3)-C(sp2) bond formation
-
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.
- Liu, Yichang,Xue, Liwei,Shi, Biyin,Bu, Faxiang,Wang, Dan,Lu, Lijun,Shi, Renyi,Lei, Aiwen
-
supporting information
p. 14922 - 14925
(2019/12/24)
-
- A visible light-driven minisci-type reaction with N-hydroxyphthalimide esters
-
A visible light-promoted protocol for the redox-neutral coupling of N-hydroxyphthalimide esters with different N-heterocyclic compounds is described. The reaction proceeds through an alkyl radical intermediate generated by reductive decarboxylation of N-hydroxyphthalimide esters. In contrast to the original Minisci protocol, polyalkylation can largely be avoided. Mechanistic investigations revealed a radical chain mechanism which in some cases can proceed even if no photocatalyst is added. This valuable and functional group-tolerant reaction produces substituted heterocycles in moderate to excellent yield. The use of inexpensive starting materials and LEDs as the light source are key features of this C–C bond formation.
- Kammer, Lisa Marie,Rahman, Aliyaah,Opatz, Till
-
-
- Ru-Photoredox-Catalyzed Decarboxylative Oxygenation of Aliphatic Carboxylic Acids through N-(acyloxy)phthalimide
-
Decarboxylative aminoxylation of aliphatic carboxylic acid derivatives with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) in the presence of ruthenium photoredox catalysis is reported. The key transformation entails a highly efficient photoredox catalytic cycle using Hantzsch ester as a reductant. The ensuing alkoxyamine can be readily converted to the corresponding alcohol in one pot, representing an alternative approach to access aliphatic alcohols under photoredox conditions.
- Zheng, Chao,Wang, Yuting,Xu, Yangrui,Chen, Zhen,Chen, Guangying,Liang, Steven H.
-
supporting information
p. 4824 - 4827
(2018/08/24)
-
- Zinc-Mediated Decarboxylative Alkylation of Gem-difluoroalkenes
-
An efficient and mild zinc-mediated decarboxylative alkylation of gem-difluoroalkenes with N-hydroxyphthalimide (NHP) esters, to give monofluoroalkenes in moderate to excellent yields with high Z-selectivity is reported. The reaction tolerates a broad range of functional groups and can be easily scaled up, which thus may pave the way for its further applications in medicinal chemistry and materials science.
- Yu, Liting,Tang, Mei-Lin,Si, Chang-Mei,Meng, Zhi,Liang, Yongxi,Han, Jilai,Sun, Xun
-
supporting information
p. 4579 - 4583
(2018/08/09)
-
- Heteroleptic Copper(I)-Based Complexes for Photocatalysis: Combinatorial Assembly, Discovery, and Optimization
-
A library of 50 copper-based complexes derived from bisphosphines and diamines was prepared and evaluated in three mechanistically distinct photocatalytic reactions. In all cases, a copper-based catalyst was identified to afford high yields, where new heteroleptic complexes derived from the bisphosphine BINAP displayed high efficiency across all reaction types. Importantly, the evaluation of the library of copper complexes revealed that even when photophysical data is available, it is not always possible to predict which catalyst structure will be efficient or inefficient in a given process, emphasizing the advantages for catalyst structures with high modularity and structural variability.
- Minozzi, Clémentine,Caron, Antoine,Grenier-Petel, Jean-Christophe,Santandrea, Jeffrey,Collins, Shawn K.
-
supporting information
p. 5477 - 5481
(2018/05/01)
-
- Photoredox-Catalyzed Decarboxylative Alkylation of Silyl Enol Ethers to Synthesize Functionalized Aryl Alkyl Ketones
-
Photoredox-catalyzed decarboxylative alkylation of silyl enol ethers has been developed. Diverse functionalized aryl alkyl ketones were afforded in modest to good yields using N-(acyloxy)phthalimide as an easy access alkyl radical source under mild and operationally simple conditions. The excellent performance of drug molecules such as fenbufen and indomethacin and naturally occurring carboxylic acids such as stearic acid and dehydrocholic acid further demonstrated the practicability of the reaction.
- Kong, Weiguang,Yu, Changjiang,An, Hejun,Song, Qiuling
-
supporting information
p. 349 - 352
(2018/01/28)
-