31508-44-8Relevant academic research and scientific papers
Continuous in situ electrogenaration of a 2-pyrrolidone anion in a microreactor: application to highly efficient monoalkylation of methyl phenylacetate
Matsumura, Yoshimasa,Kakizaki, Yoshinobu,Tateno, Hiroyuki,Kashiwagi, Tsuneo,Yamaji, Yoshiyuki,Atobe, Mahito
, p. 96851 - 96854 (2015)
We have successfully demonstrated effective generation of an electrogenerated base (EGB) such as the 2-pyrrolidone anion and its rapid use for the following alkylation reaction in a flow microreactor system without the need for severe reaction conditions. The key feature of the method is effective and selective preparation of monoalkylated products.
Asymmetric Aminations and Kinetic Resolution of Acyclic α-Branched Ynones
He, Faqian,Shen, Guosong,Yang, Xiaoyu
supporting information, p. 15 - 20 (2021/11/20)
An efficient method for asymmetric synthesis of acyclic α-tertiary amine derivatives has been achieved through enantioselective aminations of α-branched ynones with azodicarboxylates enabled by chiral phosphoric acid catalysis. Moreover, kinetic resolution of racemic starting material was realized under these conditions, which gave access to valuable enantioenriched α-substituted ketones. A wide array of α-aryl and alkyl-substitutions, and the substituted alkynyl groups were well compatible with this method, producing both the amination products and the recovered ketones with good to high enantioselectivities.
Palladium-Catalyzed Asymmetric Hydroesterification of α-Aryl Acrylic Acids to Chiral Substituted Succinates
Ji, Xiaolei,Shen, Chaoren,Tian, Xinxin,Dong, Kaiwu
supporting information, 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.
Regio- And Stereoselective (S N2) N -, O -, C - And S -Alkylation Using Trialkyl Phosphates
Banerjee, Amit,Hattori, Tomohiro,Yamamoto, Hisashi
, (2021/06/16)
Bimolecular nucleophilic substitution (S N 2) is one of the most well-known fundamental reactions in organic chemistry to generate new molecules from two molecules. In principle, a nucleophile attacks from the back side of an alkylating agent having a suitable leaving group, most commonly a halide. However, alkyl halides are expensive, very harmful, toxic and not so stable, which makes them problematic for laboratory use. In contrast, trialkyl phosphates are inexpensive, readily accessible and stable at room temperature, under air, and are easy to handle, but rarely used as alkylating agents in organic synthesis. Here, we describe a mild, straightforward and powerful method for nucleophilic alkylation of various N -, O -, C - and S -nucleophiles using readily available trialkyl phosphates. The reaction proceeds smoothly in excellent yield, and quantitative yield in many cases, and covers a wide range of substrates. Further, the rare stereoselective transfer of secondary alkyl groups has been achieved with inversion of configuration of chiral centers (up to 98% ee).
Preparation of alkylated compounds using the trialkylphosphate
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Paragraph 0238-0239, (2021/11/02)
[Problem] trialkylphosphate strong base used reaction agent, a carboxylic acid, a ketone, an aldehyde, amine, amide, thiol, ester or Grignard reagent to a variety of substrates, and/or high efficiency to generate a highly stereoselective alkylation reaction, the alkylated compounds capable of producing new means. [Solution] was used as the alkylating agent in the alkylation of compound trialkylphosphate, strongly basic reaction production use. [Drawing] no
Structural elucidation of chiral (imino)pyridine/phosphine palladium(II) complexes and their applications as catalysts in methoxycarbonylation of styrene
Akiri, Saphan O.,Ngcobo, Nondumiso L.,Ogweno, Aloice O.,Ojwach, Stephen O.
, (2021/06/15)
Treatment of ligands (S)-1-phenyl-N-(1-(pyridin-2-yl)ethylidene)ethanamine (L1), (R)-1-phenyl-N-(1-(pyridin-2-yl)ethylidene)ethanamine (L2), (S)-1-phenyl-N-((pyridin-2-yl)methylene)ethanamine (L3), (R)-1-phenyl-N-((pyridin-2-yl)methylene)ethanamine (L4), (S)-N-(2-(diphenylphosphino)benzylidene)-1-phenylethanamine (L5), and (R)-N-(2-(diphenylphosphino)benzylidene)-1-phenylethanamine (L6) with [Pd(COD)Cl2] afforded the respective palladium complexes [Pd(L1)Cl2] (1), [Pd(L2)Cl2] (2), [Pd(L3)Cl2] (3), [Pd(L4)Cl2] (4), [Pd(L5)Cl2] (5) and [Pd(L6)Cl2] (6) in high yields. Solid-state structures of the complexes established N^N and N^P bidentate coordination mode of the ligands to give distorted square planar geometries. Complexes 1–6 displayed moderate catalytic activities in the methoxycarbonylation of styrene, to give predominantly branched esters of up to 95%. NMR spectroscopy studies pointed to possible decomposition of the active species, via ligand dissociation.
Sterically hindered (pyridyl)benzamidine palladium(II) complexes: Syntheses, structural studies, and applications as catalysts in the methoxycarbonylation of olefins
Akiri, Saphan O.,Ojwach, Stephen O.
, (2021/09/09)
Reactions of ligands (E)-N′-(2,6-diisopropylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L1), (E)-N′-(2,6-diisopropylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L2), (E)-N′-(2,6-dimethylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L3), (E)-N′-(2,6-dimethylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L4), and (E)-N-(6-methylpyridin-2-yl)-N′-phenylbenzimidamide (L5) with [Pd(NCMe)2Cl2] furnished the corresponding palladium(II) precatalysts (Pd1–Pd5), in good yields. Molecular structures of Pd2 and Pd3 revealed that the ligands coordinate in a N^N bidentate mode to afford square planar compounds. Activation of the palladium(II) complexes with para-tolyl sulfonic acid (PTSA) afforded active catalysts in the methoxycarbonylation of a number of alkene. The resultant catalytic activities were controlled by the both the complex structure and alkene substrate. While aliphatic substrates favored the formation of linear esters (>70%), styrene substrate resulted in the formation of predominantly branched esters of up to 91%.
Green Esterification of Carboxylic Acids Promoted by tert-Butyl Nitrite
Cheng, Xionglve,Jiang, Gangzhong,Li, Xingxing,Tao, Suyan,Wan, Xiaobing,Zhao, Yanwei,Zheng, Yonggao
supporting information, p. 2713 - 2718 (2021/06/25)
In this work, the green esterification of carboxylic acids promoted by tert-butyl nitrite has been well developed. This transformation is compatible with a broad range of substrates and exhibits excellent functional group tolerance. Various drugs and substituted amino acids are applicable to this reaction under near neutral conditions, with good to excellent yields.
Iodoarene-Catalyzed Oxyamination of Unactivated Alkenes to Synthesize 5-Imino-2-Tetrahydrofuranyl Methanamine Derivatives
Deng, Xiao-Jun,Liu, Hui-Xia,Zhang, Lu-Wen,Zhang, Guan-Yu,Yu, Zhi-Xiang,He, Wei
, p. 235 - 253 (2021/01/09)
Reported here is the room-temperature metal-free iodoarene-catalyzed oxyamination of unactivated alkenes. In this process, the alkenes are difunctionalized by the oxygen atom of the amide group and the nitrogen in an exogenous HNTs2 molecule. This mild and open-air reaction provided an efficient synthesis to N-bistosyl-substituted 5-imino-2-tetrahydrofuranyl methanamine derivatives, which are important motifs in drug development and biological studies. Mechanistic study based on experiments and density functional theory calculations showed that this transformation proceeds via activation of the substrate alkene by an in situ generated cationic iodonium(III) intermediate, which is subsequently attacked by an oxygen atom (instead of nitrogen) of amides to form a five-membered ring intermediate. Finally, this intermediate undergoes an SN2 reaction by NTs2 as the nucleophile to give the oxygen and nitrogen difunctionalized 5-imino-2-tetrahydrofuranyl methanamine product. An asymmetric variant of the present alkene oxyamination using chiral iodoarenes as catalysts also gave promising results for some of the substrates.
Enantioselective α-Arylation of Ketones via a Novel Cu(I)-Bis(phosphine) Dioxide Catalytic System
Escudero-Casao, Margarita,Licini, Giulia,Orlandi, Manuel
supporting information, p. 3289 - 3294 (2021/04/07)
A novel catalytic system based on copper(I) and chiral bis(phosphine) dioxides is described. This allows the arylation of silyl enol ethers to access enolizable α-arylated ketones in good yields and enantiomeric excess up to 95%. Noncyclic ketones are amenable substrates with this method, which complements other approaches based on palladium catalysis. Optimization of the ligand structure is accomplished via rational design driven by correlation analysis. Preliminary mechanistic hypotheses are also evaluated in order to identify the role of chiral bis(phosphine) dioxides.
