28131-17-1Relevant academic research and scientific papers
Free-Radical-Promoted Copper-Catalyzed Decarboxylative Alkylation of α,β-Unsaturated Carboxylic Acids with ICH2CF3 and Its Analogues
Zhu, Yan,Gong, Juwen,Wang, Yonghui
, p. 7428 - 7436 (2017)
A novel and efficient free-radical-promoted copper-catalyzed decarboxylative alkylation of α,β-unsaturated carboxylic acids with ICH2CF3 and its analogues has been developed. This methodology provides a convenient access to the synthesis of allylic trifluoromethyl and β-CF3 ketone containing compounds as well as other biologically useful fluorinated molecules and materials.
Hydrocarboxylation of alkynes with formic acid over multifunctional ligand modified Pd-catalyst with co-catalytic effect
Chen, Xiao-Chao,Guo, Lin,Liu, Lei,Liu, Ye,Lu, Yong,Yao, Yin-Qing,Zhao, Xiao-Li
, p. 322 - 332 (2022/01/06)
Hydrocarboxylation of terminal alkynes with formic acid (FA) was accomplished over a multifunctional ligand (L2) modified Pd-catalyst, advantageous with 100% atom-economy, free use of CO and H2O, mild reaction conditions, and high yields (56–89%) of α,β-unsaturated carboxylic acids with 100% regioselectivity to the branched ones. The multifunctional ligand of L2 as a zwitterion salt containing the phosphino-fragment (-PPh2), Lewis acidic phosphonium cation and sulfonate group (-SO3?), was constructed on the skeleton of 1.1′-binaphthyl-2.2′-diphenyl phosphine (BINAP) upon selective quaternization by 1,3-propanesultone. It was found that L2 conferred to the Pd-catalyst the co-catalytic effect, wherein the phosphino-coordinated Pd-complex was responsible for activation of all the substrates (including CO, FA and alkyne), and the incorporated phosphonium cation was responsible for synergetic activation of FA. The 1H NMR spectroscopic analysis supported that FA was truly activated by the incorporated Lewis acidic phosphonium cation in L2 via “acid-base pair” interaction. The in situ FT-IR spectra demonstrated that, the presence of Ac2O and NaOAc additives in the catalytic amount could dramatically promote the in situ release of CO from FA, which was required to initiate the hydrocarboxylation.
Rh-Catalyzed Coupling of Acrylic/Benzoic Acids with α-Diazocarbonyl Compounds: An Alternative Route for α-Pyrones and Isocoumarins
Hong, Chao,Liu, Zhanxiang,Yu, Shuling,Zhang, Yuhong
, p. 815 - 820 (2022/02/07)
A coupling of acrylic acids/benzoic acids with α-diazocarbonyl compounds has been realized by a combined catalytic system of rhodium catalyst and Zn(OAc)2 additive. The presence of Zn(OAc)2 obviously accelerates the C(sp2)
Synthesis of Cyclopentenones through Rhodium-Catalyzed C-H Annulation of Acrylic Acids with Formaldehyde and Malonates
Yu, Shuling,Hong, Chao,Liu, Zhanxiang,Zhang, Yuhong
, p. 5054 - 5059 (2021/07/20)
An efficient rhodium-catalyzed protocol for the synthesis of cyclopentenones based on a three-component reaction of acrylic acids, formaldehyde, and malonates via vinylic C-H activation is reported. Exploratory studies showed that 5-alkylation of as-prepared cyclopentenones could be realized smoothly by the treatment of a variety of alkyl halides with a Na2CO3/MeOH solution. Excess formaldehyde and malonate led to a multicomponent reaction that afforded the multisubstituted cyclopentenones through a Michael addition.
Palladium-Catalyzed Asymmetric Hydroesterification of α-Aryl Acrylic Acids to Chiral Substituted Succinates
Ji, Xiaolei,Shen, Chaoren,Tian, Xinxin,Dong, Kaiwu
, p. 8645 - 8649 (2021/10/25)
A palladium-catalyzed asymmetric hydroesterification of α-aryl acrylic acids with CO and alcohol was developed, preparing a variety of chiral α-substituted succinates in moderate yields with high ee values. The kinetic profile of the reaction progress revealed that the alkene substrate first underwent the hydroesterification followed by esterification with alcohol. The origin of the enantioselectivity was elucidated by density functional theory computation.
Cobalt-Catalyzed Vinylic C-H Addition to Formaldehyde: Synthesis of Butenolides from Acrylic Acids and HCHO
Yu, Shuling,Hong, Chao,Liu, Zhanxiang,Zhang, Yuhong
, p. 8359 - 8364 (2021/11/01)
A carboxyl-assisted C-H functionalization of acrylic acids with formaldehyde to give butenolides is described. It is the first time that the addition of an inert vinylic C-H bond to formaldehyde has been achieved via cobalt-catalyzed C-H activation. The unique reactivity of the cobalt species was observed when compared with related Rh or Ir catalysts. γ-Hydroxymethylated butenolides were produced by the treatment of Na2CO3 after the catalytic reaction in one pot.
Electrochemical oxidative: Z -selective C(sp2)-H chlorination of acrylamides
Coles, Simon J.,Hareram, Mishra Deepak,Harnedy, James,Morrill, Louis C.,Tizzard, Graham J.
, p. 12643 - 12646 (2021/12/07)
An electrochemical method for the oxidative Z-selective C(sp2)-H chlorination of acrylamides has been developed. This catalyst and organic oxidant free method is applicable across various substituted tertiary acrylamides, and provides access to a broad range of synthetically useful Z-β-chloroacrylamides in good yields (22 examples, 73% average yield). The orthogonal derivatization of the products was demonstrated through chemoselective transformations and the electrochemical process was performed on gram scale in flow.
3,3′-Disubstituted Oxindoles Formation via Copper-Catalyzed Arylboration and Arylsilylation of Alkenes
Liang, Ren-Xiao,Chen, Ru-Yi,Zhong, Chao,Zhu, Jia-Wen,Cao, Zhong-Yan,Jia, Yi-Xia
supporting information, p. 3215 - 3218 (2020/04/10)
Arylboration and arylsilylation reactions of N-(2-iodoaryl)acrylamides with bis(pinacolato)-diboron (B2pin2) or PhMe2Si-Bpin are developed by using simple CuOAc as the sole catalyst. A range of boron-or silane-bearing 3,3′-disubstituted oxindoles are obtained in moderate to excellent yields. The reaction is proposed to proceed via a domino sequence involving intermolecular olefin borylcupration or silylcupration followed by intramolecular coupling of an alkyl-Cu intermediate with aryl iodide.
Iodonium Ylides as Carbene Precursors in Rh(III)-Catalyzed C-H Activation
Jiang, Yuqin,Li, Pengfei,Li, Xingwei,Liu, Bingxian,Zhao, Jie
, p. 7475 - 7479 (2020/10/12)
The rhodium(III)-catalyzed coupling of C-H substrates with iodonium ylides has been realized for the efficient synthesis of diverse cyclic skeletons, where the iodonium ylides have been identified as efficient and outstanding carbene precursors. The reaction systems are applicable to both sp2 and sp3 C-H substrates under mild and redox-neutral conditions. The catalyst loading can be as low as 0.5 mol % in a gram-scale reaction. Representative products exhibit cytotoxicity toward human cancer cells at nanomolar levels.
A 1,3,2-Diazaphospholene-Catalyzed Reductive Claisen Rearrangement
Reed, John H.,Donets, Pavel A.,Miaskiewicz, Solène,Cramer, Nicolai
, p. 8893 - 8897 (2019/05/28)
1,3,2-Diazaphospholenes (DAPs) are an emerging class of organic hydrides. In this work, we exploited them as efficient catalysts for very mild reductive Claisen rearrangements. The method is tolerant towards a wide variety of functional groups and operates at ambient temperature. Besides being enantiospecific for substrates with existing stereogenic centers, the diastereoselectivity can be switched by varying solvents and DAP catalysts. The reaction kinetics show direct rearrangements of O-bound phospholene enolates and provide a proof-of-principle for catalytic enantioselective reactions.
