912-17-4Relevant articles and documents
Tunable System for Electrochemical Reduction of Ketones and Phthalimides
Chen, Gong,Qiao, Tianjiao,Wang, Yaxin,Zhang, Jian,Zhao, Jianyou
supporting information, p. 3297 - 3302 (2021/10/14)
Herein, we report an efficient, tunable system for electrochemical reduction of ketones and phthalimides at room temperature without the need for stoichiometric external reductants. By utilizing NaN3 as the electrolyte and graphite felt as both the cathode and the anode, we were able to selectively reduce the carbonyl groups of the substrates to alcohols, pinacols, or methylene groups by judiciously choosing the solvent and an acidic additive. The reaction conditions were compatible with a diverse array of functional groups, and phthalimides could undergo one-pot reductive cyclization to afford products with indolizidine scaffolds. Mechanistic studies showed that the reactions involved electron, proton, and hydrogen atom transfers. Importantly, an N3/HN3 cycle operated as a hydrogen atom shuttle, which was critical for reduction of the carbonyl groups to methylene groups.
Semiconductor Photocatalysis: Size Control of Surface-Capped CdS Nanocrystallites and the Quantum Size Effect in Their Photocatalysis
Yanagida, Shozo,Ogata, Tomoyuki,Shindo, Akihiro,Hosokawa, Hiroji,Mori, Hirotaro,et al.
, p. 752 - 758 (2007/10/02)
Size-controlled CdS nanocrystallites were prepared by using thiophenol or hexanethiol as a capping reagent by controlling the ratio of Cd2+ to bis(trimethylsilyl) sulfide (S(TMS)2) as a source of the sulfide ion in reversed micelles.Their solubility and photocatalysis were examined.A series of size-controlled phenyl-capped CdS nanocrystallites catalyze the photoreduction of aromatic ketones in the presence of triethylamine as an electron donor under visible-light irradiation.The photocatalytic activity is affected by the particle size, i.e., the reducing power of the photogenerated electron on CdS nanocrystallites toward the ketones increases with decreasing the particle size.The enhancement of photocatalytic activity observed by reducing the particle size should be ascribed to not only a negative shift of the conduction band edge, but also suppression of the formation of surface defects.
Semiconductor Photocatalysis: Visible Light Induced Photoreduction of Aromatic Ketones and Electron-deficient Alkenes catalysed by Quantised Cadmium Sulfide
Shiragami, Tsutomu,Ankyu, Hirofumi,Fukami, Shinako,Pac, Chyongjin,Yanagida, Shozo,et al.
, p. 1055 - 1062 (2007/10/02)
Colloidal CdS suspensions (CdS-0) prepared at 0 deg C from methanolic Cd(ClO4)2 and Na2S solutions consist of quantised CdS microcrystallites (2-5 nm) and their loose aggregates, which catalyse the effective photoreduction of aromatic ketones and electron-deficient alkenes with triethylamine as electron donor.Under visible light induced photolysis, the methanolic CdS-0 suspension becomes brown owing to the reduction of lattice Cd2+ to Cd0, leading to the effective formation of alcohols from ketones, and dihydro compounds from alkenes.With the reduction potential2-) in the CdS-0 system, however, suppresses the formation of lattice Cd0, inducing one-electron transfer photoreductions which result in the exclusive formation of pinacols and 1,2,3,4-tetra(methoxycarbonyl)butane from the respective ketones and dimethyl maleate.The relationship between the two-electron reductions and the photogenerated lattice Cd0 is discussed in terms of the regulation of semiconductor photocatalysis.
