19444-84-9Relevant articles and documents
Synthesis of α-hydroxy-γ-butyrolactones from acrylates and 1,3-dioxolanes using N-hydroxyphthalimide (NHPI) as a key catalyst
Kagayama, Takashi,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 3687 - 3689 (2005)
A new route to α-hydroxy-γ-butyrolactones through three-component radical coupling of 1,3-dioxoranes, acrylates, and molecular oxygen using N-hydroxyphthalimide (NHPI) as a key catalyst has been developed. For example, the addition of 1,3-dioxarane to methyl acrylate under dioxygen by NHPI followed by catalytic hydrogenation of the resulting adduct on Pd/C afforded α-hydroxy-γ-butyrolactone in good yield. This method provides a facile approach to α-hydroxy-γ-butyrolactones, which are difficult to synthesize by conventional methods.
Preparation method of DL-hydroxy selenomethionine
-
Paragraph 0008; 0018-0019, (2021/06/02)
The invention belongs to the field of preparation of organic compounds. The invention provides a preparation method of DL-hydroxy selenomethionine. The method is characterized in that gamma-butyrolactone is used as a raw material, alpha-hydroxyl-gamma-butyrolactone is synthesized through alpha-bromination and hydroxylation, and then the alpha-hydroxyl-gamma-butyrolactone reacts with sodium methyl selenol to obtain the DL-hydroxyl selenomethionine. The method has the advantages of easily available raw materials, mild reaction conditions and low cost, and is suitable for large-scale preparation of DL-hydroxyselenomethionine.
Visible light-induced Minisci reaction through photoexcitation of surface Ti-peroxo species
Naniwa, Shimpei,Yamamoto, Akira,Yoshida, Hisao
, p. 3376 - 3384 (2021/06/06)
Photocatalytic Minisci-type functionalization of pyridine with tetrahydrofuran (THF) proceeded using hydrogen peroxide (H2O2) and a TiO2photocatalyst under acidic conditions. Under UV light (λ= 360 nm), the reaction selectivity based on pyridine (Spy) was >99% while the selectivity based on THF (STHF) was low such as 19%. In contrast, under visible light (λ= 400 or 420 nm)Spywas similarly high (>99%) andSTHFwas two times higher than that under UV light. A surface peroxo complex formed upon contact of hydrogen peroxide with the TiO2surface can be selectively photoexcited by visible light to inject the photoexcited electron to the conduction band of TiO2. The electron can reduce H2O2to a reactive oxygen species (ROS) and promote selectively the Minisci-type cross-coupling reaction between pyridinium ions and THF. A reaction test with a hole scavenger (methanol) evidenced that the hole oxidation of H2O2under UV light is responsible for the lower selectivity, in other words, the higher selectivity under visible light would be due to suppression of the hole oxidation of H2O2. These results demonstrate a novel way to improve the selectivity of the photocatalytic cross-coupling reaction by using H2O2as an oxidant with the photoexcitation of surface Ti-peroxo species on TiO2