Carboboration‐Driven Generation of a Silylium Ion for Vinylic C−F Bond Functionalization by B(C
<sub>6</sub>
F
<sub>5</sub>
)
<sub>3</sub>
Catalysis
作者:Tetsuji Yata、Yoshihiro Nishimoto、Makoto Yasuda
DOI:10.1002/chem.202103852
日期:2022.2
B(C6F5)3-catalyzed reactions between fluoroalkenes and silyl ketene acetals gave vinylic C−F bond-functionalized products under mild and simple conditions. Carboboration reaction of fluoroalkenes generates an oxygen-stabilized silylium ion to facilitate the C−F bond cleavage. DFT and IBO studies were performed to clear the reaction mechanism. A comparative study of α-chloro or bromostyrenes demonstrated
Addition of Silyl Ketene Acetals to Nitrones Catalyzed by Lanthanide Triflates
作者:Changtao Qian、Longcheng Wang
DOI:10.1016/s0040-4020(00)00636-0
日期:2000.9
α-Aryl-N-phenyl nitrones reacted with silyl ketene acetals mediated by lanthanum trifloromethanesulfonate (triflate) to afford the addition product in excellent yield under mild conditions. α-Aryl-N-tert-butyl nitrone reacted with ethyl trimethylsilylacetate to yield the unexpected α,β-unsaturated ester in a 100% E-form. A possible mechanism for the process is discussed.
The titanium tetrachloride catalyzed condensation of the title acetals with aldehydes, leads to threo or erythro β-hydroxyacids with good stereoselectivity which depends mainly on the nature of the acetal counterion.
Addition Reactions of Polyhalides to Ketene Silyl Acetals and Silyl Enol Ethers under Thermal or Photo-Irradiated Conditions without a Promoter
作者:Michiharu Mitani、Hideo Sakata、Hisayuki Tabei
DOI:10.1246/bcsj.75.1807
日期:2002.8
The reactions of ketene silyl acetals and silylenolethers in a CCl4 solution containing no promoter under ambient temperature, reflux, or photo-irradiation conditions afforded products via the addition of a trichloromethyl group to those silyl substrates. Polyhalides other than CCl4 were subjected to photoreactions in a hexane solution, resulting in the formation of carbonyl derivatives based on