1674-30-2Relevant articles and documents
In Situ Formation and Reactions of Chloromethyl-lithium under Sonochemical Conditions
Einhorn, Cathy,Allavena, Corinne,Luche, Jean-Louis
, p. 333 - 334 (1988)
Under sonication, bromochloromethane, a carbonyl compound, and lithium in tetrahydrofuran yield the corresponding α-chlorohydrin, which can cyclise to the epoxide, in excellent yields.
Dihydroxylation of styrene by sodium chlorite with scandium triflate
Ohkubo, Kei,Hirose, Kensaku,Shibata, Takekatsu,Takamori, Kiyoto,Fukuzumi, Shunichi
, (2017)
Dihydroxylation of styrene by chlorite (ClO2 ?) with scandium triflate [Sc(OTf)3] occurs efficiently to produce 1-phenylethane-1,2-diol under the ambient conditions. Scandium triflate acting as a strong Lewis acid is found to accelerate the disproportionation of ClO2 ? to produce ClO? and ClO3 ?. A scandium-chlorine dioxide complex (Sc3+ClO2 ?) is generated by the reaction of ClO? with ClO2 ? in the presence of Sc3 +. The binding of Sc3 + to ClO2 ? was detected by the electron paramagnetic resonance measurements, enhancing the reactivity and selectivity of styrene hydroxylation.
A phosphonium ylide as a visible light organophotoredox catalyst
Toda, Yasunori,Tanaka, Katsumi,Matsuda, Riki,Sakamoto, Tomoyuki,Katsumi, Shiho,Shimizu, Masahiro,Ito, Fuyuki,Suga, Hiroyuki
supporting information, p. 3591 - 3594 (2021/04/14)
A phosphonium ylide-based visible light organophotoredox catalyst has been designed and successfully applied to halohydrin synthesis using trichloroacetonitrile and epoxides. An oxidative quenching cycle by the ylide catalyst was established, which was confirmed by experimental mechanistic studies.
Dynamic Kinetic Resolution of Alcohols by Enantioselective Silylation Enabled by Two Orthogonal Transition-Metal Catalysts
Oestreich, Martin,Seliger, Jan
supporting information, p. 247 - 251 (2020/10/29)
A nonenzymatic dynamic kinetic resolution of acyclic and cyclic benzylic alcohols is reported. The approach merges rapid transition-metal-catalyzed alcohol racemization and enantioselective Cu-H-catalyzed dehydrogenative Si-O coupling of alcohols and hydrosilanes. The catalytic processes are orthogonal, and the racemization catalyst does not promote any background reactions such as the racemization of the silyl ether and its unselective formation. Often-used ruthenium half-sandwich complexes are not suitable but a bifunctional ruthenium pincer complex perfectly fulfills this purpose. By this, enantioselective silylation of racemic alcohol mixtures is achieved in high yields and with good levels of enantioselection.
Lipase mediated enzymatic kinetic resolution of phenylethyl halohydrins acetates: A case of study and rationalization
Fonseca, Thiago de Sousa,Vega, Kimberly Benedetti,da Silva, Marcos Reinaldo,de Oliveira, Maria da Concei??o Ferreira,de Lemos, Telma Leda Gomes,Contente, Martina Letizia,Molinari, Francesco,Cespugli, Marco,Fortuna, Sara,Gardossi, Lucia,de Mattos, Marcos Carlos
, (2020/02/18)
Racemic phenylethyl halohydrins acetates containing several groups attached to the aromatic ring were resolved via hydrolysis reaction in the presence of lipase B from Candida antarctica (Novozym 435). In all cases, the kinetic resolution was highly selective (E > 200) leading to the corresponding (S)-β-halohydrin with ee > 99 %. However, the time required for an ideal 50 % conversion ranged from 15 min for 2,4-dichlorophenyl chlorohydrin acetate to 216 h for 2-chlorophenyl bromohydrin acetate. Six chlorohydrins and five bromohydrins were evaluated, the latter being less reactive. For the β-brominated substrates, steric hindrance on the aromatic ring played a crucial role, which was not observed for the β-chlorinated derivatives. To shed light on the different reaction rates, docking studies were carried out with all the substrates using MD simulations. The computational data obtained for the β-brominated substrates, based on the parameters analysed such as NAC (near attack conformation), distance between Ser-O and carbonyl-C and oxyanion site stabilization were in agreement with the experimental results. On the other hand, the data obtained for β-chlorinated substrates suggested that physical aspects such as high hydrophobicity or induced change in the conformation of the enzymatic active site are more relevant aspects when compared to steric hindrance effects.
