- Visible Light Enabled Formal Cross Silyl Benzoin Reaction as an Access to α-Hydroxyketones
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In this work, a visible-light enabled coupling of acylsilanes with aldehydes to give a range of cross-benzoin type products α-hydroxyketones is described. The reaction could proceed at ambient temperature, with the irradiation of low energy visible light, and without addition of photosensitizer or any other additives. (Figure presented.).
- Ma, Liyao,Yu, Yinghua,Xin, Luoting,Zhu, Lei,Xia, Jiajin,Ou, Pengcheng,Huang, Xueliang
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supporting information
p. 2573 - 2577
(2021/04/05)
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- De Novo Synthesis of α-Hydroxy Ketones by Gallic Acid-Promoted Aerobic Coupling of Terminal Alkynes with Diazonium Salts
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An unprecedented metal-free direct preparation of unprotected α-hydroxy ketones from terminal alkynes under mild conditions with diazonium salts as the arene source and without the requirement of irradiation is described. The process is general and fully compatible with a wide variety of substitution in both reactants. Experimental and computational evidence strongly suggest the involvement of radical species in the transformation.
- Alcaide, Benito,Almendros, Pedro,Fernández, Israel,Herrera, Fernando,Luna, Amparo
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supporting information
p. 17227 - 17230
(2017/11/23)
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- Synthesis and reactivities of 1,3-dimethyl-2-(α-hydroxy-benzyl)imidazolium and 1,3-dimethyl-2-(α-hydroxybenzyl)benzimidazolium iodides
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1,3-Dimethyl-2-(α-hydroxybenzyl)benzimidazolium iodide (3a) was synthesized from 1-methylbenzimidazole (10) through two steps involving lithiation and quaternization. Treatment of 3a with 4-chloro-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (6) afforded 4-benzoyl-1-phenyl-1H-pyrazolo[3,4-d]pyrimidine (15a). 4-Benzoylquinazoline (14a) and 7-benzoyl-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidine (16a) were given by reaction of 3a with 4-chloroquinazoline (5) and 7-chloro-3-phenyl-3H-1,2,3-triazolo[4,5-d]pyrimidine (7). Treatment of 3a with benzaldehyde (9a) gave benzoin (8a). Similar results were obtained in the reactions of 1,3-dimethyl-2-(α-hydroxybenzyl)imidazolium iodide (4a).
- Miyashita, Akira,Kurachi, Akihito,Matsuoka, Yoshiyuki,Tanabe, Noriko,Suzuki, Yumiko,Iwamoto, Ken-Ichi,Higashino, Takeo
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p. 417 - 426
(2007/10/03)
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- Reductive Coupling of Benzoyl Cyanide and Carbonyl Compounds by Aqueous Ti(III) Ions. A New Convenient and Selective Access to the Less Stable Mixed Benzoins
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The reactive species formed by the Ti(III) ion reduction of benzoyl cyanide (1) adds to the C-atom of carbonyl compounds 2 under simple experimental conditions.The intermediate 1,2-diols 3 are smoothly converted, without isolation, into the less thermodynamically stable mixed benzoins 4, which are not accessible by the classical benzoin condensation.The possible mechanisms involved in the reaction are discussed.
- Clerici, Angelo,Porta, Ombretta
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p. 2889 - 2893
(2007/10/02)
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- CYANOHYDRINS AS SUBSTRATES IN BENZOIN CONDENSATION. REGIOCONTROLLED MIXED BENZOIN CONDENSATION
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O-Benzoylated cyanohydrins of aromatic aldehydes have been used as one of the substrates in the benzoin condensation.They were treated with aromatic aldehydes under phase-transfer conditions to result in benzoin benzoates.By this method aldehydes which fail to undergo condensation using traditional conditions could be converted into benzoins.By the Umpolung of reactivity of the pertinent aldehyde it was possible to prepare both isomeric unsymmetrical benzoins, including the thermodynamically less stable ones.
- Rozwadowska, Maria D.
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p. 3135 - 3140
(2007/10/02)
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- Preparation and antiinflammatory activity of some nonacidic trisubstituted imidazoles
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A number of trisubstituted imidazoles were made and several found to be potent antiinflammatory agents when examined in the carrageenan rat paw edema test. The antiinflammatory activity of these compounds is retained in adrenalectomized rats. Unlike many previously reported antiinflammatory agents, these compounds are extremely weak acids pK[a] ≥ 11) and are therefore not ionized at physiological pH. One compound, 4,5 bis (4 methoxyphenyl) 2 trifluoromethylimidazole (flumizole), is more potent than indometacin in the rat paw edema test and, in contrast to some related compounds, does not cause photosensitization in mice.
- Lombardino,Wiseman
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p. 1182 - 1188
(2007/10/04)
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