Palladium-catalyzed enantioselective allylic alkylation of trifluoromethyl group substituted racemic and acyclic unsymmetrical 1,3-disubstituted allylic esters with malonate anions
We examined the palladium-catalyzedallylic alkylation of trifluoromethyl group-substituted racemic and acyclic unsymmetrical 1,3-disubstituted allylic benzoate with a malonate anion, and succeeded in obtaining an enantiomerically enriched product in high yields with high ee values through the dynamic kinetic asymmetric transformation (DYKAT). The best result was attained by the [Pd(C3H5)(cod)]BF4/(S)-tol-BINAP
我们研究了三氟甲基取代的外消旋和无环不对称1,3-二取代的烯丙基苯甲酸酯与丙二酸阴离子的钯催化的烯丙基烷基化,并通过动态动力学不对称转化成功获得了高收率,高ee值的对映体富集产品。 (DYKAT)。在BSA或DMAP作为碱的情况下,通过[Pd(C 3 H 5)(cod)] BF 4 /(S)-tol-BINAP可获得最佳结果。
One-Step Diastereoselective Pyrrolidine Synthesis Using a Sulfinamide Annulating Reagent
作者:Qing Shi、Nathaniel S. Greenwood、Mariah C. Meehan、Hyunsoo Park、Michael Galella、Bhupinder Sandhu、Purnima Khandelwal、John R. Coombs、William P. Gallagher、Carlos A. Guerrero、John Hynes、T. G. Murali Dhar、Francisco Gonzalez Bobes、David Marcoux
DOI:10.1021/acs.orglett.9b03560
日期:2019.11.15
highlights the use of chiral sulfinamides as nitrogen nucleophiles in intermolecular aza-Michael reactions. When chiral sulfinamides are coupled to a chloroethyl group, the corresponding novel annulating reagents can be used to streamline the stereoselective synthesis of complex pyrrolidine-containing molecules. As a result, it has enabled a medicinal chemistry campaign for the synthesis of biologically
practical phosphine‐catalyzed vicinal difunctionalization of β‐fluoroalkyl α,β‐enones with TMSN3 has been developed. Using dppb as the catalyst, the reaction worked efficiently to yield various β‐amino α‐diazocarbonyl compounds in high yields (up to 94 %). This work marks the first efficient construction of α‐diazocarbonyl compounds by phosphine catalysis. Meanwhile, the asymmetric variant induced by the
has been accomplished in the presence of a chiral N,N′‐dioxide/[Sc(OTf)3] complex (0.5–2 mol %), delivering the desired vicinal anti‐α‐iodo‐β‐amino carbonyl compounds regioselectively in high yields (up to 97 %) and with excellent diastereoselectivities (>99:1 d.r.) and enantioselectivities (up to 99 % ee). Enantiopure syn‐α‐iodo‐β‐amino products could also be obtained from the isomerization of particular
Redox‐Divergent Synthesis of Fluoroalkylated Pyridines and 2‐Pyridones through Cu‐Catalyzed N−O Cleavage of Oxime Acetates
作者:Dachang Bai、Xueli Wang、Guangfan Zheng、Xingwei Li
DOI:10.1002/anie.201802311
日期:2018.5.28
Cu‐catalyzed redox‐divergent [3+3] coupling of oxime esters with β‐CF3 enones and acrylates is described. This redox‐neutral coupling with enones and acrylates affords trifluoromethylated pyridines and pyridones, respectively. Under reductive conditions, difluoromethylated pyridines, difluoromethlated pyridones, and trifluoromethylated dihydropyridones are obtained. The reactions occur under mild conditions