Highly Enantioselective Copper-Catalyzed Alkylation of β-Ketoesters and Subsequent Cyclization to Spirolactones/Bi-spirolactones
作者:Qing-Hai Deng、Hubert Wadepohl、Lutz H. Gade
DOI:10.1021/ja211859w
日期:2012.2.15
Cu-catalyzed enantioselective alkylation of β-ketoesters using alcohols for in situ preparation of alkylating reagents is reported. A number of functionalized β-ketoesters containing a quaternary carbon stereocenter are obtained with up to 99% ee. The alkylation products derived from 2-substituted allylic alcohols or their corresponding iodides can then be converted to spirolactones, bi-spirolactones
报道了使用醇对 β-酮酯进行 Cu 催化的对映选择性烷基化,用于原位制备烷基化试剂。获得了许多含有季碳立体中心的官能化 β-酮酯,ee 高达 99%。然后可以将衍生自 2-取代烯丙醇或其相应碘化物的烷基化产物转化为螺内酯、双螺内酯和相关的手性目标产物。
<i>N</i>-Trifluoromethylthiophthalimide: A Stable Electrophilic SCF<sub>3</sub>-Reagent and its Application in the Catalytic Asymmetric Trifluoromethylsulfenylation
Cinchona alkaloid catalysts in combination with air‐ and moisture‐stable N‐trifluoromethylthiophthalimide as electrophilic SCF3 source enabled the catalytic enantioselective trifluoromethylsulfenylation. Thus, a series of α‐SCF3 esters that bear a quaternary carbon stereogenic center were obtained with excellent yield and enantioselectivity. Moreover, the products can be readily converted into valuable
developed for the asymmetricsynthesis of bisphosphonate derivatives, a class of pharmaceutically important molecules. Cheap and commercially available dihydroquinine effectively catalyzed conjugate additions of cyclic beta-ketoesters to ethylidenebisphosphonate esters, leading to optically active geminal bisphosphonates, bearing an all-carbonsubstitutedquaternarystereocenter, in high yields and
Highly Enantioselective Copper-Catalyzed Electrophilic Trifluoromethylation of β-Ketoesters
作者:Qing-Hai Deng、Hubert Wadepohl、Lutz H. Gade
DOI:10.1021/ja3039773
日期:2012.7.4
Enantioselective Cu-catalyzed trifluoromethylation of β-ketoesters using commercially available trifluoromethylating reagents is reported. A number of α-CF(3) β-ketoesters are obtained with up to 99% ee. The trifluoromethylated products were then transformed diastereoselectively to α-CF(3) β-hydroxyesters with two adjacent quaternary stereocenters via a Grignard reaction.
报道了使用市售三氟甲基化试剂对 β-酮酯进行对映选择性 Cu 催化的三氟甲基化。获得了许多具有高达 99% ee 的 α-CF(3) β-酮酯。然后通过格氏反应将三氟甲基化产物非对映选择性地转化为具有两个相邻季立体中心的 α-CF(3) β-羟基酯。
Copper-Boxmi Complexes as Highly Enantioselective Catalysts for Electrophilic Trifluoromethylthiolations
作者:Qing-Hai Deng、Christoph Rettenmeier、Hubert Wadepohl、Lutz H. Gade
DOI:10.1002/chem.201303641
日期:2014.1.3
The enantioselectivetrifluoromethylthiolation of β‐ketoesters using chiral copper–boxmicomplexes as catalysts is reported. A number of α‐SCF3‐substituted β‐ketoesters have been obtained with up to >99 % enantiomeric excess (ee), and the trifluoromethylthiolated products were then transformed diastereoselectively to α‐SCF3‐β‐hydroxyesters with two adjacent quaternary stereocenters.