51965-61-8Relevant articles and documents
Methylation with Dimethyl Carbonate/Dimethyl Sulfide Mixtures: An Integrated Process without Addition of Acid/Base and Formation of Residual Salts
Chan, Bun,Lui, Matthew Y.,Lui, Yuen Wai
, (2022/01/08)
Dimethyl sulfide, a major byproduct of the Kraft pulping process, was used as an inexpensive and sustainable catalyst/co-reagent (methyl donor) for various methylations with dimethyl carbonate (as both reagent and solvent), which afforded excellent yields of O-methylated phenols and benzoic acids, and mono-C-methylated arylacetonitriles. Furthermore, these products could be isolated using a remarkably straightforward workup and purification procedure, realized by dimethyl sulfide‘s neutral and distillable nature and the absence of residual salts. The likely mechanisms of these methylations were elucidated using experimental and theoretical methods, which revealed that the key step involves the generation of a highly reactive trimethylsulfonium methylcarbonate intermediate. The phenol methylation process represents a rare example of a Williamson-type reaction that occurs without the addition of a Br?nsted base.
Rhenium(I)-Catalyzed C-Methylation of Ketones, Indoles, and Arylacetonitriles Using Methanol
Shee, Sujan,Kundu, Sabuj
, p. 6943 - 6951 (2021/05/29)
A ReCl(CO)5/MeC(CH2PPh2)3 (L2) system was developed for the C-methylation reactions utilizing methanol and base, following the borrowing hydrogen strategy. Diverse ketones, indoles, and arylacetonitriles underwent mono-and dimethylation selectively up to 99% yield. Remarkably, tandem multiple methylations were also achieved by employing this catalytic system.
Rationalizing the Unprecedented Stereochemistry of an Enzymatic Nitrile Synthesis through a Combined Computational and Experimental Approach
Yavuzer, Hilmi,Asano, Yasuhisa,Gr?ger, Harald
supporting information, p. 19162 - 19168 (2021/07/26)
In this contribution, the unique and unprecedented stereochemical phenomenon of an aldoxime dehydratase-catalyzed enantioselective dehydration of racemic E- and Z-aldoximes with selective formation of both enantiomeric forms of a chiral nitrile is rationalized by means of molecular modelling, comprising in silico mutations and docking studies. This theoretical investigation gave detailed insight into why with the same enzyme the use of racemic E- and Z-aldoximes leads to opposite forms of the chiral nitrile. The calculated mutants with a larger or smaller cavity in the active site were then prepared and used in biotransformations, showing the theoretically predicted decrease and increase of the enantioselectivities in these nitrile syntheses. This validated model also enabled the rational design of mutants with a smaller cavity, which gave superior enantioselectivities compared to the known wild-type enzyme, with excellent E-values of up to E>200 when the mutant OxdRE-Leu145Phe was utilized.
Overcoming Selectivity Issues in Reversible Catalysis: A Transfer Hydrocyanation Exhibiting High Kinetic Control
Bhawal, Benjamin N.,Ehinger, Christian,Morandi, Bill,Reisenbauer, Julia C.
supporting information, p. 10914 - 10920 (2020/07/13)
Reversible catalytic reactions operate under thermodynamic control, and thus, establishing a selective catalytic system poses a considerable challenge. Herein, we report a reversible transfer hydrocyanation protocol that exhibits high selectivity for the thermodynamically less favorable branched isomer. Selectivity is achieved by exploiting the lower barrier for C-CN oxidative addition and reductive elimination at benzylic positions in the absence of a cocatalytic Lewis acid. Through the design of a novel type of HCN donor, a practical, branched-selective, HCN-free transfer hydrocyanation was realized. The synthetically useful resolution of a mixture of branched and linear nitrile isomers was also demonstrated to underline the value of reversible and selective transfer reactions. In a broader context, this work demonstrates that high kinetic selectivity can be achieved in reversible transfer reactions, thus opening new horizons for their synthetic applications.
Preparation method of alkyl nitrile compound
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Paragraph 0130-0132; 0156-0158, (2020/08/18)
The invention discloses a preparation method of an alkyl nitrile compound. Specifically, the preparation method comprises the following step: in an organic solvent, in the presence of a protective gasand under the action of a catalyst, carrying out a reduction reaction as shown in the specification on olefin as shown in a formula I, a cyanation reagent and water, wherein the alkyl nitrile compound 1 is a compound II and/or a compound III. The preparation method provided by the invention is mild in condition, can realize hydrocyanation of olefin more safely and efficiently, and has good substrate universality and functional group compatibility.
Luminescent tungsten(vi) complexes as photocatalysts for light-driven C-C and C-B bond formation reactions
Chan, Kaai-Tung,Che, Chi-Ming,Du, Lili,Liu, Yungen,Phillips, David Lee,To, Wai-Pong,Tong, Glenna So Ming,Wu, Liang-Liang,Yu, Daohong
, p. 6370 - 6382 (2020/07/15)
The realization of photocatalysis for practical synthetic application hinges on the development of inexpensive photocatalysts which can be prepared on a large scale. Herein an air-stable, visible-light-absorbing photoluminescent tungsten(vi) complex which can be conveniently prepared at the gram-scale is described. This complex could catalyse photochemical organic transformation reactions including borylation of aryl halides, such as aryl chloride, reductive coupling of benzyl bromides for C-C bond formation, reductive coupling of phenacyl bromides, and decarboxylative coupling of redox-active esters of alkyl carboxylic acid with high product yields and broad functional group tolerance.
Ni-Catalyzed hydrocyanation of alkenes with formamide as the cyano source
Shu, Xiao,Jiang, Yuan-Yuan,Kang, Lei,Yang, Luo
supporting information, p. 2734 - 2738 (2020/06/17)
CN generation from formamide dehydration! A novel Ni-catalyzed hydrocyanation of various alkenes to provide aliphatic nitriles is developed by generating hydrocyanic acid in situ from safe and readily available formamide. Excellent linear or branched regio-selectivity, wide substrate scope, cheap and stable nickel salt as a pre-catalyst, a safe cyano source, slow generation of CN to obviate catalyst deactivation and convenient experimental operation would render this hydrocyanation attactive for laboratory synthesis of aliphatic nitriles.
Nickel-Catalyzed Markovnikov Transfer Hydrocyanation in the Absence of Lewis Acid
Frye, Nils L.,Bhunia, Anup,Studer, Armido
supporting information, p. 4456 - 4460 (2020/06/03)
Hydrocyanation in the absence of toxic HCN gas is highly desirable. Addressing that challenge, transition-metal-catalyzed transfer hydrocyanation using safe HCN precursors has been developed, but these reagents generally require a Lewis acid for activation, and the control of regioselectivity often remains problematic. In this Letter, a Ni-catalyzed highly Markovnikov-selective transfer hydrocyanation that operates in the absence of any Lewis acid is reported. The readily prepared pro-aromatic 1-isopropylcyclohexa-2,5-diene-1-carbonitrile is used as the HCN source, and the reaction shows a broad substrate scope and high functional group tolerance. Terminal styrene derivatives, dienes, and internal alkynes are converted with good to excellent selectivities. Mechanistic studies provide insights into the origin of the regioselectivity.
α-Methylation of 2-Arylacetonitrile by a Trimethylamine-Borane/CO2 System
Zhang, Xiaowei,Wang, Sheng,Xi, Chanjuan
, p. 9744 - 9749 (2019/08/16)
A highly selective monomethylation of 2-arylacetonitrile using CO2 is described. The utilization of trimethylamine-borane facilitates the six-electron reduction of CO2. This reaction is the first selective six-electron reductive functionalization of CO2 faciliated by C(sp3)-H bonds. A variety of 2-arylpropionitrile was obtained in good yields. The reaction could also be applied at the gram scale.
NOVEL COMPOUNDS
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Page/Page column 46, (2019/03/05)
The invention relates to compounds of Formula (I) and their use in therapy, for example in the treatment of mycobacterial infections or in the treatment of diseases caused by mycobacterium, such as tuberculosis