2653-86-3Relevant academic research and scientific papers
Selective hydroboration of equilibrating allylic azides
Liu, Ruzhang,Xu, Jun,Zhang, Yuanyuan
supporting information, p. 8913 - 8916 (2021/09/13)
The iridium(i)-catalyzed hydroboration of equilibrating allylic azides is reported to provide only the anti-Markovnikov product of alk-1-ene isomers in good yields and with good functional group tolerance.
Diethylzinc-Mediated Radical 1,2-Addition of Alkenes and Alkynes
Li, Xin,He, Songtao,Song, Qiuling
supporting information, p. 2994 - 2999 (2021/05/04)
A novel diethylzinc-mediated radical 1,2-addition of perfluoroalkyl iodides to unactivated alkenes and alkynes is presented, which demonstrates a novel way to generate an ethyl difluoroacetate radical. This method is highly efficient and gives full conversions of the substrates, high yields of the products, and negligible byproducts and requires no column chromatography purifications. The mild conditions enable this protocol to exhibit excellent functional group compatibility.
Nickel-Catalyzed Hydrosilylation of Terminal Alkenes with Primary Silanes via Electrophilic Silicon-Hydrogen Bond Activation
Wu, Xiaoyu,Ding, Guangni,Lu, Wenkui,Yang, Liqun,Wang, Jingyang,Zhang, Yuxuan,Xie, Xiaomin,Zhang, Zhaoguo
, p. 1434 - 1439 (2021/02/16)
We report a simple and effective nickel-based catalytic system, NiCl2·6H2O/tBuOK, for the electrophilically activated hydrosilylation of terminal alkenes with primary silanes. This protocol provides excellent performance under mild reaction conditions: ex
Copper-Catalyzed 1,2-Bistrifluoromethylation of Terminal Alkenes
Oh, Hyunseok,Park, Areum,Jeong, Kyu-Sung,Han, Soo Bong,Lee, Hyuk
supporting information, p. 2136 - 2140 (2019/03/13)
Many efficient catalytic methods for the introduction of trifluoromethyl group (CF3) have been reported. Among them, the addition of CF3 and other components to alkenes is well known, and many components such as azides, cyanides, amines, and halides have been inserted into alkenes with CF3. However, to date the double catalytic insertion of CF3 into an alkene is unknown. Herein, we report the catalytic 1,2-bistrifluoromethylations of alkenes catalyzed by Copper (Cu). We used two CF3 sources, namely Umemoto's reagent and (trifluoromethyl)trimethylsilane (TMSCF3). Each reagent plays a unique role during this transformation; Umemoto's reagent generates CF3 radicals, while TMSCF3 is used to form CF3 anions. Copper (I) bromide (CuBr) exhibited the best catalytic activity for this reaction. We believe that CuBr oxidizes the alkyl radical, which is produced by the addition of the CF3 radical to the alkene, to the corresponding alkyl cation, which then reacts with the CF3 anion from TMSCF3 to produce the desired product. This reaction tolerates a diverse set of substrates bearing functional groups such as amides, esters, ethers, ketones, protected amines, tertiary amines, and phthalimides; hence this transformation is widely applicable to a wide variety of substrates. (Figure presented.).
Palladium-Catalyzed Intermolecular Ditrifluoromethoxylation of Unactivated Alkenes: CF3O-Palladation Initiated by Pd(IV)
Chen, Chaohuang,Luo, Yixin,Fu, Liang,Chen, Pinhong,Lan, Yu,Liu, Guosheng
supporting information, p. 1207 - 1210 (2018/02/09)
A novel palladium-catalyzed intermolecular ditrifluoromethoxylation of unactivated alkenes has been developed, using a new electrophilic reagent, SelectfluorCN, as a strong oxidant, and AgOCF3 as a trifluoromethoxide source. Preliminary mechanistic studies revealed that the reaction was possibly initiated by Pd(IV) species, and an unusual cis-addition of CF3O-Pd(IV) into the double bond leads to the formation of the first C-OCF3 bond; in addition, the second C-OCF3 bond was produced through reductive elimination at high-valent palladium center.
Selective Isomerization of Terminal Alkenes to (Z)-2-Alkenes Catalyzed by an Air-Stable Molybdenum(0) Complex
Becica, Joseph,Glaze, Owen D.,Wozniak, Derek I.,Dobereiner, Graham E.
, p. 482 - 490 (2018/02/17)
Positional and stereochemical selectivity in the isomerization of terminal alkenes to internal alkenes is observed using the cis-Mo(CO)4(PPh3)2 precatalyst. A p-toluenesulfonic acid (TsOH) cocatalyst is essential for catalyst activity. Various functionalized terminal alkenes have been converted to the corresponding 2-alkenes, generally favoring the Z isomer with selectivity as high as 8:1 Z:E at high conversion. Interrogation of the catalyst initiation mechanism by 31P NMR reveals that cis-Mo(CO)4(PPh3)2 reacts with TsOH at elevated temperatures to yield a phosphine-ligated Mo hydride (MoH) species. Catalysis may proceed via 2,1-insertion of a terminal alkene into a MoH group and stereoselective β-hydride elimination to yield the (Z)-2-alkene.
Tuning Regioselectivity of Wacker Oxidation in One Catalytic System: Small Change Makes Big Step
Hu, Kang-Fei,Ning, Xiao-Shan,Qu, Jian-Ping,Kang, Yan-Biao
, p. 11327 - 11332 (2018/09/06)
A regioselectivity switchable aerobic Wacker-Tsuji oxidation has been developed using catalytic tert-butyl nitrite as a simple organic redox cocatalyst. By solely switching the solvent, either substituted aldehydes or ketones could be prepared under mild
Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb under Syngas Conditions
Amézquita-Valencia, Manuel,Alper, Howard
, p. 3860 - 3867 (2016/05/24)
A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives.
Catalytic nucleophilic fluorination by an imidazolium ionic liquid possessing trialkylphosphine oxide functionality
Paramanik, Minakshmi,Singh, Rekha,Mukhopadhyay, Sulekha,Ghosh, Sunil K.
, p. 47 - 55 (2015/07/15)
Abstract The synthesis of a new alkylmethylimidazolium ionic liquid wherein the alkyl group is functionalized with dihexylphosphine oxide moiety at the terminal position has been achieved in four steps from 1-methylimidazole. This hybrid ionic liquid effectively catalyzed the nucleophilic fluorination of primary alkyl mesylates under mild conditions using CsF as the fluoride source with a faster rate compared to butylmethylimidazolium mesylate. The hybrid catalyst was recycled 5 times without compromising the yield and purity of the product. The nucleophilic fluorination has been used for the synthesis of diethyl 2-(5-fluoropentyl)-2-methyl malonate, a precursor of 18F isotopomer of an apoptosis imaging agent and the protected form of O-(2'-fluoroethyl)-l-tyrosine, a 18F isotopomer of a tumor imaging agent.
