Asymmetric alkynylation of thiazolones and azlactones with alkynylbenziodoxolones as the electrophilic alkyne source catalyzed by thiourea phosphonium salt is described. By using thiazolones as nucleophiles, the desired alkyne functionalized thiazolones were obtained in 55–89% yields with 31–86% ee. Azlactones gave the desired products in comparable yields with lower enantioselectivities. Ring-opening
描述了硫脲鏻盐催化的噻唑酮和吖内酯的不对称炔基化反应,其中炔基苯并氧唑酮作为亲电炔烃源。通过使用噻唑酮作为亲核试剂,以 55-89% 的产率和 31-86% 的 ee 获得所需的炔烃官能化噻唑酮。Azlactones 以较低的对映选择性以相当的产率得到所需的产物。炔基化产物的开环导致α,α-二取代的α-氨基酸衍生物有效而不会损失对映选择性。
Catalytic asymmetric formal [3+2] cycloaddition of isatogens with azlactones to construct indolin-3-one derivatives
作者:Lihua Xie、Yi Li、Shunxi Dong、Xiaoming Feng、Xiaohua Liu
DOI:10.1039/d0cc06418a
日期:——
A number of enantioenriched indolin-3-one derivatives were readily obtained by chiral guanidine-catalyzed [3+2] cycloaddition of isatogens with azlactones.
An asymmetric inverse-electron-demandhetero-Diels-Alderreaction between o-quinone methides and azlactones to generate potentially pharmacological active dihydrocoumarins has been achieved efficiently by using a chiral N,N'-dioxide-Sc(III) complex as the catalyst. The desired products were obtained in high yields with excellent enantioselectivities and diastereoselectivities (up to 94% yield, 96%
COAP-Pd Catalyzed Asymmetric Allylic Alkylation of Azlactones with MBH Carbonates: Access to Unnatural α-Quaternary Stereogenic Glutamic Acid Derivatives
作者:Sheng-Suo Zhou、Xing-Yun Sun、Wen-Kai Liu、Jia-Yu Song、Zheng Wang、Zheng-Hang Qi、Xing-Wang Wang
DOI:10.1021/acs.joc.3c01152
日期:2023.8.18
palladium-catalyzed regioselective and asymmetric allylic alkylation of azlactones with MBH carbonates has been developed with chiral oxalamide-phosphine ligands. The corresponding reaction afforded a range of optically active γ-arylidenyl glutamic acid derivatives bearing an α-chiral quaternarystereocenter in good yields with excellent linear regio- and high enantioselectivity. This protocol furnishes
pyrrolidine-catalyzed three-component reaction of azlactone, N,O-acetal and alcohol for the synthesis of α,β-diamino ester was reported. The N,O-acetal served as the imine equivalent to occur Mannich reaction with azlactone, and the in situ generated α-functionalized azlactone subsequently underwent a ring-opening process in the presence of alcohol. A series of α,β-diamino esters were obtained in 36–99% yields