Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- and α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
作者:Xiao-Yu Zhan、Hua Zhang、Yu Dong、Jian Yang、Shuai He、Zhi-Chuan Shi、Lei Tang、Ji-Yu Wang
DOI:10.1021/acs.joc.0c00568
日期:2020.5.15
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies
benzylation of 1,3-dicarbonylcompounds. β-Keto enol ethers were obtained when cyclic1,3-dicarbonylcompounds used in this conditions instead of linear ones. The present methodology offers a practical, simple, mild, environmentally friendly, and time-saving method for etherification. Very low loading of catalyst, ease of workup, ease of handling, and reusability of catalyst are other advantages of
Amberlyst-15® in ionic liquid: an efficient and recyclable reagent for the benzylation and hydroalkylation of β-dicarbonyl compounds
作者:Ziyauddin S. Qureshi、Krishna M. Deshmukh、Pawan J. Tambade、Bhalchandra M. Bhanage
DOI:10.1016/j.tetlet.2009.11.122
日期:2010.1
Benzylation and hydroalkylation of 1,3-dicarbonylcompounds using Amberlyst-15 immobilized in ionic liquid [Bmim][PF6] as an efficient reusable reagent was studied. The reagent was compared with other solid acid reagents along with role of the ionic liquid. The effect of various reaction parameters like type of reagent, solvent, substrate molar ratio, reaction time, and temperature were studied. Present
作者:Can-Can Bao、Dong-Song Zheng、Xiao Zhang、Shu-Li You
DOI:10.1021/acs.organomet.8b00762
日期:2018.12.24
N-Heterocyclic carbenes (NHCs) were found to be suitable ligands in Ir-catalyzed intermolecular allylic alkylation reaction. In the presence of a catalyst derived from [Ir(dncot)Cl]2 (dncot = dinaphthocyclooctatetraene) and triazolium salt L7, the alkylation products from the reaction of aryl allyl carbonates with sodium dialkyl malonates could be obtained in 85–99% yields favoring the formation of
发现N-杂环卡宾(NHC)是Ir催化的分子间烯丙基烷基化反应中的合适配体。在[Ir(dncot)Cl] 2(dncot =二萘环辛酸酯四烯)和三唑鎓盐L7衍生的催化剂存在下,芳基烯丙基碳酸酯与二烷基丙二酸钠的反应可得到烷基化产物,收率高达85-99%,形成支链产物(90/10→> 99/1 b / l)。此外,手性二氢异喹啉型NHC(DHIQ-NHC)(L8)已成功应用于Ir催化的不对称烯丙基烷基化反应中。对于广泛的底物,获得了优异的对映选择性和中等的区域选择性。
Regio- and Enantioselective Rhodium-Catalyzed Allylic Alkylation of Racemic Allylic Alcohols with 1,3-Diketones
作者:Sheng-Biao Tang、Xiao Zhang、Hang-Fei Tu、Shu-Li You
DOI:10.1021/jacs.8b05126
日期:2018.6.20
Highly regio- and enantioselective rhodium-catalyzed allylicalkylation of 1,3-diketones with racemic secondary allylic alcohols is reported. In the presence of a Rh-catalyst derived from the Carreira (P, olefin)-ligand and TFA as an additive, chiral branched α-allylated 1,3-diketones could be obtained in good to excellent yields, with excellent regio- and enantioselectivity ( b/ l > 19/1, 86-98% ee)