- A Simple and Efficient Method for the Preparation of α-Halogenated Ketones Using Iron(III) Chloride and Iron(III) Bromide as Halogen Sources with Phenyliodonium Diacetate as Oxidant
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α-Halogenated ketones are both unique structure moieties existing in biologically natural products and valuable synthetic intermediates for the preparation of functional molecules. An efficient and scalable method for the preparation of α-halogenated ketone using iron (III) chloride and iron (III) bromide as halogen sources with phenyliodonium diacetate as oxidant has been developed, featuring mild reaction conditions, environmentally friendly reagents, and wide substrate scope. Notably, the three-step synthesis of drug prasugrel was achieved using this developed method as a key step with 30% yield on gram-scale. Additionally, the reaction mechanism involving chloride cation was proposed based on some preliminary control experiments. (Figure presented.).
- Tang, Shi-Zhong,Zhao, Wenshuang,Chen, Tao,Liu, Yang,Zhang, Xiao-Ming,Zhang, Fu-Min
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supporting information
p. 4177 - 4183
(2017/12/18)
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- Transformation of tertiary benzyl alcohols into the vicinal halo-substituted derivatives using N-Halosuccinimides
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The efficiency of direct conversion of tertiary alcohols bearing a-hydrogen atom to vicinal halohydrins-chlorohydrins and bromohydrins-under green reaction conditions was tested preliminarily on modeltertiary benzyl alcohols. Tertiary alcohols were successfully directly halogenated to vicinal halohydrins with N-halosuccinimide in aqueous media. The efficiency of the reaction in water was significantly improved in the presence of sodium dodecyl sulphate as the surfactant.
- Ajvazi, Njomza,Stavber, Stojan
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- External trapping of halomethyllithium enabled by flow microreactors
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This work demonstrates that the accurate control of the reaction parameters realized within microreactor systems allowed for a taming of the reactivity of thermally unstable intermediates such as haloalkyllithiums. The first example of effective external trapping of a reactive carbenoid such as the chloromethyllithium is described. By using microreactor systems, a continuous flow synthesis of chloro alcohols and chloro amines could be achieved with high yields. By controlling the residence time the highly reactive chloromethyllithium could be generated and reacted with electrophiles at temperatures much higher than in batch-mode and without internal quenching. The developed continuous-flow process matches the requirements for sustainability.
- Degennaro, Leonardo,Fanelli, Flavio,Giovine, Arianna,Luisi, Renzo
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supporting information
p. 21 - 27
(2015/01/30)
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- Solid-state organic reactions proceeding by pulverization: Oxidation and halogenation with iodosobenzene and inorganic solid-supports
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Pulverization-activation method was employed to accelerate solid-state organic reactions. Crushing and grinding of solid mixtures of hydrogen halide-treated silica gels, iodosobenzene and organic substrates in the absence of a solvent brought about smooth and rapid reactions to give halogenated and/or oxidized products in good yields. Various sulfides were smoothly converted to sulfonyl chlorides in one step in excellent yields. The surface of silica gel activated by pulverization serves as a reaction field on which reagent molecules can effectively encounter with each other.
- Sohmiya, Hajime,Kimura, Takahide,Fujita, Mitsue,Ando, Takashi
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p. 13737 - 13750
(2007/10/03)
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- Antifungal triazole ethanol derivatives
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Antifungal and plant growth regulatory compounds of the formula STR1 in which R1 is alkyl, cycloalkyl or optionally substituted phenyl, and R2 is optionally substituted phenyl or benzyl.
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- β-Substituted Organolithium Compounds from Chlorohydrins: Application to the Direct Synthesis of Bifunctionalized Organic Cpmpounds
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The reaction of different chlorohydrins with n-butyl-lithium at -78 deg C followed by metallation wiht lithium naphthalenide at the same temperature leads to very reactive organolithium compounds bearing an alkoxide function at the β-position with respect to metal.The reaction of these intermediates with several electriphiles leads to mono- as well as bi-functionalized organic compounds.Thus, treatment of these dianions with deuterium oxide, oxygen, carbon dioxide, benzyl bromide, dimethyl disulphide, and carbonyl compounds, gave 2-deuterioalcohols, 1,2-diols, β-hydroxy-acids, 2-benzyl alcohols, 2-hydroxy-thioethers, and 1,3-diols respectively.The preparation of β-substituted organolithium derivatives can be alternatively carried out starting from α-chloroketones by the same procedure.When the lithium atom is linked to a secondary carbon atom the dianions are very unstable and decompose, even at -100 deg C, by β-elimination yielding the corresponding olefins.
- Barluenga, Jose,Florez, Josefa,Yus, Miguel
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p. 3019 - 3026
(2007/10/02)
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- Tertiary imidazolyl alcohols and method for the treatment of generalized and local infections caused by fungi and yeasts
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The present invention is directed to new tertiary imidazolyl alcohols having the general formula (I) STR1 and to their pharmacologically acceptable acid addition salts with usual acids. The invention is further directed to a method for the treatment of generalized and local infections caused by fungi or yeasts by administering to a mammal suffering from such a disease a compound of the general formula (I) orally or externally in a suitable pharmaceutical preparation.
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