Ruthenium(II)-Catalyzed C–H Alkynylation of Heterocycles under Chelation Assistance

An efficient ruthenium(II)-catalyzed, chelation-assisted C–H alkynylation of heterocycles is described using hypervalent iodine–alkyne as an alkynylating reagent. This reaction proceeds smoothly under mild conditions with high regioselectivity and good functional group tolerance, delivering the desired alkynylated indoles, thiophene, furan, and pyrrole in high yields.

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Bromotrifluoromethane: A Useful Reagent for Hydrotrifluoromethylation of Alkenes and Alkynes

Synlett ◽

10.1055/s-0036-1591944 ◽

2018 ◽

Vol 29 (08) ◽

pp. 1028-1032 ◽

Cited By ~ 5

Author(s):

Xing Zheng ◽

Xingang Zhang ◽

Yu-Yan Ren

Keyword(s):

Visible Light ◽

Organic Synthesis ◽

Functional Group ◽

Mild Conditions ◽

Industrial Material ◽

Reaction Proceeds

Bromotrifluoromethane (CF3Br) is a simple, inexpensive and abundant industrial material employed as a trifluoromethylating reagent. However, only limited strategies using CF3Br as a fluorine source are reported. Herein, we describe a visible-light-induced hydrotrifluoromethylation of alkenes and alkynes with CF3Br. The reaction proceeds under mild conditions with good functional group tolerance, providing a new route for the application of BrCF3 in organic synthesis.

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Enantioenriched Quaternary α-Pentafluoroethyl Derivatives of Alkyl 1-Indanone-2-Carboxylates

10.26434/chemrxiv.12102678 ◽

2020 ◽

Author(s):

Albert Granados ◽

Anna Balleteros ◽

Adelina Vallribera

Keyword(s):

Hypervalent Iodine ◽

Catalytic Method ◽

Quaternary Centers ◽

Mild Conditions ◽

Reaction Proceeds ◽

Mechanistic Investigations ◽

Derivatives Of

An electrophilic enantioselective catalytic method for the a-pentafluoroethylation of alkyl 1-indanone-2-carboxylates is described. Under the use of La(OTf)3 in combination with (S,R)-indanyl-pybox ligand good results in terms of yield and enantioselectivities were achieved (up to 89% ee). The reaction proceeds under mild conditions leading to the formation of enantioenriched quaternary centers. This methodology uses an hypervalent iodine(III)-CF2CF3 reagent and mechanistic investigations are consistent with the involvement of a radical pathway.

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Hypervalent Iodine-Mediated Beckmann Rearrangement of Ketoximes

Synlett ◽

10.1055/s-0037-1609686 ◽

2018 ◽

Vol 29 (11) ◽

pp. 1465-1468 ◽

Cited By ~ 4

Author(s):

Tomohiro Maegawa ◽

Yasuyoshi Miki ◽

Ryohei Oishi ◽

Kazutoshi Segi ◽

Hiromi Hamamoto ◽

...

Keyword(s):

Lewis Acid ◽

Beckmann Rearrangement ◽

Hypervalent Iodine ◽

Mild Conditions ◽

High Yields

We developed a Beckmann rearrangement employing hypervalent iodine reagent under mild conditions. The reaction of ketoxime with hypervalent iodine afforded the corresponding ketone, but premixing of hypervalent iodine and a Lewis acid was effective for promoting Beckmann rearrangement. Aromatic and aliphatic ketoximes were converted into their corresponding amides in good to high yields.

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Decarbonylation through Aldehydic C–H Bond Cleavage by a Cationic Iridium Catalyst

Synlett ◽

10.1055/s-0037-1611802 ◽

2019 ◽

Vol 30 (08) ◽

pp. 972-976 ◽

Cited By ~ 2

Author(s):

Tomohiko Shirai ◽

Kazuki Sugimoto ◽

Masaya Iwasaki ◽

Ryuki Sumida ◽

Harunori Fujita ◽

...

Keyword(s):

Bond Cleavage ◽

Catalyst System ◽

Mild Conditions ◽

Iridium Catalyst ◽

Reaction Proceeds ◽

High Yields

We report the decarbonylation of aldehydes through an aldehydic C–H bond cleavage catalyzed by a cationic iridium/bisphosphine catalyst. The reaction proceeds under relatively mild conditions to give the corresponding hydrocarbon products in moderate to high yields. In addition, this cationic iridium catalyst system can be applied to an asymmetric hydroacylation of ketones.

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Copper-Catalyzed Decarboxylative N-Arylation of Indole-2-carboxylic Acids

Synthesis ◽

10.1055/s-0037-1611946 ◽

2019 ◽

Vol 51 (08) ◽

pp. 1803-1808 ◽

Cited By ~ 1

Author(s):

Yan Zhang ◽

Zhe-Yao Hu ◽

Xin-Chang Li ◽

Xun-Xiang Guo

Keyword(s):

Carboxylic Acids ◽

Functional Group ◽

Aryl Halides ◽

Synthetic Method ◽

Alternative Route ◽

Reaction Proceeds ◽

High Yields

A novel decarboxylative N-arylation of indole-2-carboxylic acids with aryl halides is developed. The reaction proceeds efficiently in the presence of Cu2O as the catalyst to give the corresponding N-aryl indoles in high yields. This synthetic method shows good functional group tolerance and offers an alternative route to construct N-aryl indoles.

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Synthesis of O-Aroyl-N,N-dimethylhydroxylamines through Hypervalent Iodine-Mediated Amination of Carboxylic Acids with N,N-Dimethylformamide

Synthesis ◽

10.1055/s-0036-1588460 ◽

2017 ◽

Vol 49 (18) ◽

pp. 4303-4308 ◽

Cited By ~ 3

Author(s):

Dong Li ◽

Chuancheng Zhang ◽

Qiang Yue ◽

Zhen Xiao ◽

Xianglan Wang ◽

...

Keyword(s):

Carboxylic Acids ◽

Room Temperature ◽

Functional Group ◽

Hypervalent Iodine ◽

Electrophilic Amination ◽

Mild Conditions

An efficient protocol for the synthesis of O-aroyl-N,N-dimethylhydroxylamines, which are important electrophilic amination reagents, is described. The reaction between carboxylic acids and N,N-dimethylformamide is mediated by hypervalent iodine and occurs under mild conditions at room temperature to give the desired products in good yields. The process shows good functional group compatibility and air and moisture tolerance.

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Iron(III)/TEMPO-Catalyzed Synthesis of 2,5-Disubstituted 1,3,4-Oxadiazoles by Oxidative Cyclization under Mild Conditions

Synlett ◽

10.1055/s-0036-1588747 ◽

2017 ◽

Vol 28 (11) ◽

pp. 1373-1377 ◽

Cited By ~ 8

Author(s):

Chengrong Ding ◽

Guofu Zhang ◽

Yidong Yu ◽

Yiyong Zhao ◽

Xiaoqiang Xie

Keyword(s):

Functional Group ◽

Oxidative Cyclization ◽

Mild Conditions ◽

Broad Scope ◽

Oxadiazole Derivatives ◽

High Yields

A simple and efficient cationic Fe(III)/TEMPO-catalyzed oxidative cyclization of aroyl hydrazones has been developed for the synthesis of 2,5-disubstituted 1,3,4-oxadiazole derivatives. The reaction offers a broad scope, good functional-group tolerance, and high yields under mild conditions in the presence of O2.

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Additive- and Oxidant-Free Expedient Synthesis of Benzimidazoles Catalyzed by Cobalt Nanocomposites on N-Doped Carbon

Synlett ◽

10.1055/s-0037-1610353 ◽

2019 ◽

Vol 30 (03) ◽

pp. 319-324 ◽

Cited By ~ 7

Author(s):

Zhaozhan Wang ◽

Tao Song ◽

Yong Yang

Keyword(s):

Functional Group ◽

Direct Synthesis ◽

Biologically Active ◽

One Pot ◽

Mild Conditions ◽

Wide Range ◽

High Yields

A one-pot direct synthesis of a wide range of biologically active benzimidazoles through coupling of phenylenediamines and aldehydes catalyzed by a highly recyclable nonnoble cobalt nanocomposite was developed. A broad set of benzimidazoles can be efficiently synthesized in high yields and with good functional-group tolerance under additive- and oxidant-free mild conditions. The catalyst can be easily recycled for successive uses, and the process permits gram-scale syntheses of benzimidazoles.

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One-Pot Sequential Multistep Transformation of α,β-Unsaturated Trifluoromethyl Ketones: Facile Synthesis of Trifluoromethylated 2-Pyridones

Synlett ◽

10.1055/s-0037-1612077 ◽

2019 ◽

Vol 30 (05) ◽

pp. 605-609 ◽

Cited By ~ 2

Author(s):

Fa-Guang Zhang ◽

Jun-An Ma ◽

Ning Lv ◽

Yi-Qiang Tian

Keyword(s):

Facile Synthesis ◽

One Pot ◽

Good Efficiency ◽

Trifluoromethyl Ketones ◽

Mild Conditions ◽

Efficient Access ◽

Reaction Proceeds ◽

High Yields ◽

Unsaturated Trifluoromethyl Ketones

A one-pot transformation of α,β-unsaturated trifluoromethyl ketones with 2-(phenylsulfinyl)acetamide to give trifluoromethylated 2-pyridones is realized. The reaction proceeds under mild conditions and involves multiple steps in an expeditious and controlled sequence to provide efficient access to a broad range of trifluoromethylated 2-pyridones in moderate to high yields. Moreover, further synthetic manipulations permit the routine synthesis of a diverse array of trifluoromethylated pyridines with good efficiency.

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H2O as the Sole Hydrogen Source for Ni-Catalyzed Reduction of Alkenes

10.26434/chemrxiv.8067446.v1 ◽

2019 ◽

Author(s):

Yichen Wu ◽

Tao liu ◽

Dongping Chen ◽

Daoming Wang ◽

Peng Wang

Keyword(s):

Nickel Catalyst ◽

Selective Hydrogenation ◽

Functional Group ◽

Catalytic Amount ◽

Mild Conditions ◽

Water As Solvent ◽

Direct Hydrogenation ◽

High Yields

Herein, we reported a nickel catalyzed hydrogenation of alkenes with water as the sole hydrogen source. Employing Zn as reductant and water as solvent in the presence of a catalytic amount of nickel catalyst led to direct hydrogenation of a series of electron-rich and electron-deficient alkenes in high yields. This protocol features unprecedented heterocycle and functional group tolerance under facile and mild conditions. Selective hydrogenation of the substrates containing additional reducible functionalities, such as alkenyl, alkynyl, chloride, ketone, and benzyl group etc, was also realized.

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