Copper‐Catalyzed 1,2‐Bistrifluoromethylation of Terminal Alkenes
作者:Hyunseok Oh、Areum Park、Kyu‐Sung Jeong、Soo Bong Han、Hyuk Lee
DOI:10.1002/adsc.201801675
日期:2019.4.23
to alkenes is well known, and many components such as azides, cyanides, amines, and halides have been inserted into alkenes with CF3. However, to date the double catalytic insertion of CF3 into an alkene is unknown. Herein, we report the catalytic 1,2‐bistrifluoromethylations of alkenes catalyzed by Copper (Cu). We used two CF3 sources, namely Umemoto's reagent and (trifluoromethyl)trimethylsilane
Hafnium(IV) tetratriflate in selective reductive carbohydrate benzylidene acetal opening reaction and direct silylation reaction
作者:Shino Manabe、Yukishige Ito
DOI:10.1016/j.tetlet.2013.10.011
日期:2013.12
regioselective reductive benzylidene ring opening with concurrent silylation reaction. The synthetic conditions were optimized, and the scope and limitations were identified. In addition to glucose and glycosamine derivatives, mannose and galactose were successfully employed as substrates. Various protecting groups such as acetyl, allyl, and benzyl were found to be stable under the reaction conditions. By using
四三氟甲磺酸((IV)被证明是有效的催化剂,用于同时进行甲硅烷基化反应的区域选择性还原性亚苄基开环。优化了合成条件,并确定了范围和局限性。除葡萄糖和糖胺衍生物外,甘露糖和半乳糖也被成功用作底物。发现各种保护基如乙酰基,烯丙基和苄基在反应条件下是稳定的。通过使用氘代还原剂,通过S N 1机理推断反应进行。
Silyl-assisted 1,2-cis-α-glucosylation for the synthesis of a triglucoside moiety in high-mannose-type oligosaccharides
We developed a new 1,2-cis-α-glucosylation reaction, mediated by enhancing the α-favoured transition state via an electron-donating form the TBS group.