- Metal-Free Aminomethylation of Aromatic Sulfones Promoted by Eosin Y
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A metal-free α-aminomethylation of heteroaryls promoted by eosin Y under green light irradiation is reported. A large variety of α-trimethylsilylamines as precursor of α-aminomethyl radical species were engaged to functionalize sulfonyl-heteroaryls following a Homolytic Aromatic Substitution (HAS) pathway. This method has provided a range of α-aminoheteroaryl compounds including a functionalized natural product. The mechanism of this late-stage functionalization of aryls was investigated and suggests the formation of a sulfonyl radical intermediate over a reductive quenching cycle.
- Thierry, Thibault,Pfund, Emmanuel,Lequeux, Thierry
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supporting information
p. 14826 - 14830
(2021/10/01)
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- Nickel-Catalyzed Inter- and Intramolecular Aryl Thioether Metathesis by Reversible Arylation
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A nickel-catalyzed aryl thioether metathesis has been developed to access high-value thioethers. 1,2-Bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional-group-tolerant reaction. Furthermore, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis that does not involve alkene bonds. In-depth organometallic studies support a reversible Ni0/NiII pathway to product formation. Overall, this work not only provides a more sustainable alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information that are highly relevant to the further development and application of unusual single-bond metathesis reactions.
- Delcaillau, Tristan,Bismuto, Alessandro,Lian, Zhong,Morandi, Bill
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supporting information
p. 2110 - 2114
(2019/12/24)
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- Decyanative Cross-Coupling of Cyanopyrimidines with O-, S-, and N-Nucleophiles: A Route to Alkoxylpyrimidines, Aminopyrimidines and Alkylthiopyrimidines
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The transition metal-free cross-coupling reactions of cyanopyrimidines with aliphatic alcohols, thiols (or S-alkylisothiourea salts) and amines, giving the corresponding alkoxylpyrimidines, aminopyrimidines, and alkylthiopyrimidines, are reported. Prelimi
- Wei, Xiangyang,Zhang, Caiyang,Wang, Yifei,Zhan, Qi,Qiu, Guiying,Fan, Ling,Yin, Guodong
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p. 7142 - 7150
(2019/11/14)
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- Cesium carbonate-promoted synthesis of aryl methyl sulfides using: S -methylisothiourea sulfate under transition-metal-free conditions
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In the presence of cesium carbonate, an efficient synthesis of aryl methyl sulfides by the reactions of aryl halides with commercially available S-methylisothiourea sulfate is developed. This odourless and highly crystalline solid can be used as the subst
- Zhang, Caiyang,Zhou, You,Huang, Jintao,Tu, Canhui,Zhou, Xiaoai,Yin, Guodong
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p. 6316 - 6321
(2018/09/10)
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- SH-methylation of SH-containing heterocycles with dimethyl carbonate via phase-transfer catalytic reaction
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A reaction of SH-containing heterocycles with dimethyl carbonate (DMC) in the presence of K2CO3 and tetrabutylammonium bromide (Bu4NBr) gave heteroaryl methyl thioethers in 44-93% yields. The reaction was carried out under mild conditions. This method provided a useful synthetic method for preparation of various heteroaryl methyl thioethers without the use of toxic methylic halides or dimethyl sulfate.
- Xie, Jian-Gang,Quan, Jing,Li, Shu-Bai,Zheng, Yan,Zhu, Li-Min
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experimental part
p. 871 - 878
(2011/04/22)
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- Ionic liquids - Promoted S-methylation of thiols utilizing dimethyl carbonate
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Convenient and efficient S-methylation of mercaptans or thiophenols occurs with dimethyl carbonate (DMC) in room temperature ionic liquids (RTILs) [Bmim]Cl. [Bmim]Cl can be recycled in four subsequent runs with only a gradual decrease in activity. A possible mechanism of this transformation is also discussed. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file. Copyright Taylor & Francis Group, LLC.
- Xie, Jiangang,Wu, Chengyao,Christopher, Branford White,Quan, Jing,Zhu, Limin
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experimental part
p. 31 - 37
(2011/04/22)
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- Basic techniques of working on a solid phase: From ABC of the peptide synthesis to libraries of non-natural amino acids
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Libraries of hardly available amino acids bearing a heteroaromatic ring (2-pyrimidyl, substituted 2-pyridyl or 2-thiazolyl) at the amino group were prepared using solid-phase synthesis on various resins. The synthesized compounds are structurally similar to some known antidiabetic drugs. The paper combines features of a review (elementary introduction to the solid-phase synthesis methodology and technique for beginners and selected methods from peptide chemistry) and step-by-step experimental protocols (tested by the authors) useful as a methodic tool. The presented protocols (immobilization and modification of amino acids, placing and removal of common protective groups) require no sophisticated equipment and may be useful as pictorial introductory tasks for students education. Pleiades Publishing, Ltd., 2010.
- Babaev,Ermolat'ev
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scheme or table
p. 2572 - 2589
(2011/04/15)
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- Regioselectivity in the amination of methylsulfanyl-substituted azines with O-mesitylenesulfonylhydroxylamine
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Reactions of O-mesitylenesulfonylhydroxylamine with 2-(methylsulfanyl) pyrazine, 2-(methylsulfanyl) pyrimidine, and 3,5-dimethyl-2-(methylsulfanyl) pyrimidines involve both sulfur and nitrogen atoms. The amination products at the sulfur atom prevail in th
- Borodkin,Vorob'Ev,Shakirov,Shubin
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experimental part
p. 911 - 916
(2010/11/16)
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- Enzymatic synthesis of novel chiral sulfoxides employing Baeyer-villiger monooxygenases
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Optically active sulfoxides are compounds of high interest in organic chemistry. Herein, we report the preparation of a set of chiral heteroaryl alkyl, cyclohexyl alkyl, and alkyl alkyl sulfoxides by using enantioselective sulfoxidation reactions employing three Baeyer-Villiger monooxygenases (BVMOs). Careful selection of the reaction conditions, starting sulfide, and biocatalyst can be used to achieve good to excellent enantiomeric excess values. Thus, valuable chiral synthons can be obtained by performing the reactions under mild and environmentally friendly conditions. The most promising biotransformations that employ a BVMO cell-free extract preparation have been developed on a 250-mg scale to give the chiral sulfoxides in high yields in most of the reactions. Copyright
- Rioz-Martinez, Ana,De Gonzalo, Gonzalo,Pazmino, Daniel E. Torres,Fraaije, Marco W.,Gotor, Vicente
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experimental part
p. 6409 - 6416
(2011/02/24)
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- Pyrimidine-core extended π-systems: General synthesis and interesting fluorescent properties
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We have developed a simple but powerful synthetic strategy that permits the assembly of π-systems onto a pyrimidine core in a programmable and diversity-oriented format. The nucleophilic addition of ArLi to 2-methylthiopyrimidine, followed by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) oxidation, resulted in the production of 4-aryl-2-methylthiopyrimidines. The iterative reaction sequence then gave 4,6-diaryl-2-methylthiopyrimidines. The resulting adduct was further allowed to react with ArMgBr under the catalytic influence of NiCl2(dppe) to afford 2,4,6-triarylpyrimidines. By following this synthetic scheme, interesting pyrimidine-core π-systems were rapidly constructed in a programmable fashion. The successful discovery of a number of interesting fluorescent materials and properties (e.g., solvatofluorochromism) speaks well for the potential of our platform strategy in the development of functional organic materials. Copyright
- Itami, Kenichiro,Yamazaki, Daisuke,Yoshida, Jun-Ichi
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p. 15396 - 15397
(2007/10/03)
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- One-Pot Two-Step Synthesis of Aryl Sulfur Compounds by Photoinduced Reactions of Thiourea Anion with Aryl Halides
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(Equation presented) The photoinduced reactions of aryl halides with the thiourea anion afford arene thiolate ions in DMSO. These species without isolation, and by a subsequent aliphatic nucleophilic substitution, S RN1 reaction, oxidation, or protonation, yield aryl methyl sulfides, diaryl sulfides, diaryl disulfides, and aryl thiols with good yields (50-80%). This is a simple and convenient approach which involves the use of the commercially available and inexpensive thiourea in a one-pot two-step process for the synthesis of aromatic sulfur compounds.
- Argueello, Juan E.,Schmidt, Luciana C.,Penenory, Alicia B.
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p. 4133 - 4136
(2007/10/03)
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- Efficient nucleophilic substitution reactions of pyrimidyl and pyrazyl halides with nucleophiles under focused microwave irradiation
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Rapid nucleophilic displacement reactions of 2-chloropyrimidine, 2-bromopyrimidine, 5-bromopyrimidine and chloropyrazine with nucleophiles under microwave irradiation was complete within several minutes with yields up to 99%. The method using microwave irradiation is superior to the classical heating processes.
- Cherng, Yie-Jia
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p. 887 - 890
(2007/10/03)
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- Electrolytic partial fluorination of organic compounds. 35. Anodic fluorination of 2-pyrimidyl, 2-pyridyl, and 2-quinazolinonyl sulfides
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Highly regioselective electrochemical fluorination of 2-pyrimidyl sulfides having an electron-withdrawing group (EWG) at the position α to the sulfur atom was successfully carried out using Et4NF·nHF (n = 3, 4) or Et3N·3HF as a supporting electrolyte and a fluoride ion source in 1,2- dimethoxyethane (DME) in an undivided cell. 2-Methylthiopyrimidine devoid of an EWG was also selectively fluorinated in DME to provide 2- (fluoromethylthio)pyrimidine in a moderate yield as 63%, while corresponding 2-methylthiopyridine was less selectively fluorinated in lower yield along with α,α-difluorinated product. In contrast, the corresponding 2- quinazolinonyl sulfides underwent similarly α-fluorination along with unexpected ipso-fluorination through anodic desulfurization.
- Dawood, Kamal M.,Higashiya, Seiichiro,Hou, Yankun,Fuchigami, Toshio
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p. 7935 - 7939
(2007/10/03)
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- Stannylation in the Electrophilic 2- and 4/6-Pyrimidine Position and the Use of Stannylpyrimidines in Coupling and Tin-Lithium Exchange Reactions
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2-Stannylpyrimidines have been prepared by stannyl anion substitution in 2-chloropyrimidines.Stannylation in the 4-position was via the iodo-derivative or via the 4-lithio derivative and lithium-tin transmetallation.Tin-lithium exchange in the 2-position
- Sandosham, Jessie,Undheim, Kjell
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p. 275 - 284
(2007/10/02)
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- Substitution Reactions of Alkyl Iodides and α-Haloketones with Sulphur Nucleophiles: A Kinetic Study
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The reactivity of alkyl iodides and phenacyl bromides with 1,4-dihydro-4,4,6-trimethyl-1-(substituted)-pyrimidine-2-thiols has been measured conductometrically in methanol and pKa values of the thiols have been evaluated.The electron donating s
- Acharya, R. C.,Saran, N. K.,Rao, S. Raghavendra
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p. 1016 - 1018
(2007/10/02)
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