Your wish is my command: Deracemization is a powerful strategy wherein a racemate is converted into a 100 % yield of a single enantiopure product. A new concept in catalyticderacemization is presented, in which a racemate with n stereogenic elements can be selectively converted into each one of 2m (m=number of chiral centers of the product) different enantiopure products, by simple tuning of the reaction
example of oxyamination of azlactones with oxaziridines was realized using a chiral bisguanidinium salt. Efficient catalytic asymmetric oxyamination and kinetic resolution of oxaziridines occurred simultaneously. Various chiral oxazolin-4-one derivatives with potential biological activity were obtained (up to 92% ee). Meanwhile, a series of optically pure oxaziridines were recovered with up to 99% ee and
Catalytic, Enantioselective α‐Alkylation of Azlactones with Nonconjugated Alkenes by Directed Nucleopalladation
作者:Sri Krishna Nimmagadda、Mingyu Liu、Malkanthi K. Karunananda、De‐Wei Gao、Omar Apolinar、Jason S. Chen、Peng Liu、Keary M. Engle
DOI:10.1002/anie.201814272
日期:2019.3.18
palladium(II)‐catalyzed enantioselective α‐alkylation of azlactones with nonconjugated alkenes is described. The reaction employs a chiral BINOL‐derived phosphoric acid as the source of stereoinduction, and a cleavable bidentate directing group appended to the alkene to control the regioselectivity and stabilize the nucleopalladated alkylpalladium(II) intermediate in the catalytic cycle. A wide range of
Construction of allylic amino acid derivatives through a catalytic asymmetric allylic alkylation of azlactones with vinyl cyclopropanes
作者:Zhenquan Liu、Xing Feng、Jingyao Xu、Xiangxing Jiang、Xiaoqing Cai
DOI:10.1016/j.tetlet.2020.151694
日期:2020.3
A simple and concise asymmetric allylic alkylation of azlactones was developed for direct construction of quaternary amino acid derivatives. Electrophilic synthons vinyl propanes were used in the presence of Pd catalyst under mild conditions, which afforded the desired quaternary allylic amino acid derivatives in good to excellent yields with a high level of stereoselectivity
2H-chromenes has been established that uses 1,1′-binaphthyl-2,2′-diyl hydrogen phosphate (BiNPO4H) as the catalyst and gives excellent diastereoselectivities (≥19:1 dr) in most cases. This protocol has a high compatibility with various substituents of substrates, offering a catalytic and useful entry to the fabrication of the syntheticallyimportant C2-functionalized 2H-chromene scaffold.
已经建立了一种新的 Brønsted 酸催化炔丙醇与吖内酯的氧合环化以合成 C 2 -吖内酯化的2 H -色烯,其使用 1,1'-联萘-2,2'-磷酸氢二酯 (BiNPO 4 H) 作为在大多数情况下,催化剂具有出色的非对映选择性(≥19:1 dr)。该协议与底物的各种取代基具有高度相容性,为合成重要的 C 2 -功能化2 H -色烯支架的制造提供了催化和有用的入口。