62559-35-7Relevant academic research and scientific papers
Co2(CO)8-catalyzed reactions of acetals or lactones with hydrosilanes and carbon monoxide. A new access to the preparation of 1,2-diol derivatives through siloxymethylation
Chatani, Naoto,Fujii, Satoru,Kido, Yoichi,Nakayama, Yasuhide,Kajikawa, Yasuteru,Tokuhisa, Hideo,Fukumoto, Yoshiya,Murai, Shinji
, p. 81 - 90 (2021/02/05)
The Co2(CO)8-catalyzed reaction of acetals with hydrosilanes and CO under mild reaction conditions (an ambient temperature under an ambient CO pressure), leading to the production of vicinal diols is reported. A siloxymethyl group can be introduced via the cleavage of one of two alkoxy groups in the acetal. The effects of the types of hydrosilanes, acetals, solvents, and reaction temperatures on the yield of siloxymethylation products were examined in detail. The reactivity for hydrosilanes is as follows; HSiMe3 > HSiEtMe2 > HSiEt2Me > HSiEt3. Hemiacetal esters are more reactive than dimethyl acetals. The polarity of the solvent used also has a significant effect on both the course of the reaction as well as the reaction rate. The site-selective siloxymethylation can be achieved in the case of cyclic acetals such as tetrahydrofuran (THF) and tetrahydropyrane (THP) derivatives, depending on the nature of the oxygen substituent attached adjacent to the oxygen atom in the ring. When 2-alkoxy THF or THP derivatives are used as substrates, the siloxymethylation takes place with cleavage of the ring C-O bond. In contrast, the reaction of 2-acetoxy THF or THP derivatives results in siloxymethylation with the cleavage of C-OAc bond. The ring-opening siloxymethylation of lactones was also examined.
Cobalt Carbonyl Catalyzed Reactions of Cyclic Ethers with a Hydrosilane and Carbon Monoxide. A New Synthetic Reaction Equivalent to Nucleophilic Oxymethylation
Murai, Toshiaki,Yasui, Eiji,Kato, Shinzi,Hatayama, Yoshio,Suzuki, Satoshi,et al.
, p. 7938 - 7946 (2007/10/02)
Siloxymethylative ring opening of cyclic ethers has been attained by a new catalytic system of HSiR3/CO/Co2(CO)8.The reaction generally proceeded at room temperatures under 1 atm of CO.The carbon monoxide was incorporated into the product as a part of siloxymethyl group.The reactivity of cyclic ethers decreased in the order of 4 > 3 > 5 >> 6 and 7 membered ring.Among the hydrosilanes (HSiMe3, HSiEt2Me, and HSiEt3), the highly reactive HSiMe3 allowed the use of lower reaction temperature leading to high product selectivities.The regiochemical course of the reactiondepended on the substituents of the oxiranes.The reaction of monosubstituted oxiranes having electron-withdrawing groups, such as hydroxy, acetoxy, and benzoyloxy, resulted in a highly regioselective ring opening at the primary carbon center.While tert-butylethylene oxide reacted at the primary carbon, styrene oxide reacted at the secondary center.The stereochemical course of the reaction was demonstrated to be trans in the cases of cycloalkene oxides and cis- and trans-2-butene oxides.The regio- and stereoselective ring opening of allylic alcohol epoxide derivatives has been attained when their hydroxy group was converted into monochloroacetoxy group.Rare examples of incorporation of carbon monoxide into tertiary carbon centers were observed for the ring opening of geminal dialkyl-substituted oxiranes.The importance of R3SiCo(CO)4 (3) as a key catalyst species and the reaction mechanism have been discussed.An acylcobalt carbonyl intermediate generated by the stoichiometric reaction of R3SiCo(CO)4 (3) with tert-butylethylene oxide was intercepted by a 1,3-diene.
