Organocatalytic Asymmetric Cascade Michael-acyl Transfer Reaction between 2-Fluoro-1,3-diketones and Unsaturated Thiazolones: Access to Fluorinated 4-Acyloxy Thiazoles
作者:Rayhan G. Biswas、Sumit K. Ray、Rajshekhar A. Unhale、Vinod K. Singh
DOI:10.1021/acs.orglett.1c02313
日期:2021.8.20
Quinine derivedbifunctional urea catalyzed cascade Michael-acyl transfer reaction of 5-alkenyl thiazolones and monofluorinated β-diketones has been developed. The fluorine containing 4-acyloxy thiazoles were synthesized in high yields and good diastereo-and excellent enantioselectivities. Synthetic transformations, including synthesis of 4-hydroxy thiazoles, have been demonstrated.
Oxidative N-heterocyclic carbene catalyzed stereoselective annulation of simple aldehydes and 5-alkenyl thiazolones
作者:Li Lin、Yuhong Yang、Mei Wang、Luhao Lai、Yarong Guo、Rui Wang
DOI:10.1039/c5cc01587a
日期:——
A highly stereoselective annulation proceeded successfully to afford chiral thiazolo pyrones with excellent ee (up to 99%) and d.r. (up to >20 : 1). Both enantiomers can be obtained. In the presence of oxygen (O2), the oxidant O-1 can be used in a catalytic amount (even low to 2 mol%).
Enantioselective Construction of Spiro[chroman‐thiazolones]: Bifunctional Phosphonium Salt‐Catalyzed [2+4] Annulation between 5‐Alkenyl Thiazolones and
<i>ortho</i>
‐Hydroxyphenyl‐Substituted
<i>para‐</i>
Quinone Methides
作者:Jian‐Ping Tan、Hongkui Zhang、Zhiyu Jiang、Yuan Chen、Xiaoyu Ren、Chunhui Jiang、Tianli Wang
DOI:10.1002/adsc.201901413
日期:2020.3.4
The enantioselectiveformal [2+4] annulation of 5‐alkenyl thiazolones with hydroxyl‐substituted para‐quinone methides was disclosed by dipeptide‐based phosphonium salt catalysts. A wide range of functionalized spiro‐chroman‐thiazolone molecules bearing three contiguous 3° and/or 4° stereocenters were readily constructed in high yields with excellent stereoselectivities (>20:1 dr and up to >99.9% ee)
Bifunctional Squaramide‐Catalysed Asymmetric Michael/Hemiketalization/Retro‐Aldol Reaction of Unsaturated Thiazolones with α‐Nitroketones: Synthesis of Chiral 4‐Acyloxythiazole Derivatives
作者:Yong‐Xing Song、Da‐Ming Du
DOI:10.1002/adsc.201900901
日期:2019.11.5
An efficient and practical organocatalytic asymmetric cascade Michael/hemiketalization/retro‐aldolreaction of unsaturated thiazolones with α‐nitroketones by using cyclohexanediamine‐derived bifunctional squaramide as the catalyst has been developed. Under mild conditions, a broad range of chiral 4‐acyloxythiazole derivatives were obtained in high yields (up to 98% yield) with excellent enantioselectivities
Asymmetric synthesis of spirooxindole-fused spirothiazolones<i>via</i>squaramide-catalysed reaction of 3-chlorooxindoles with 5-alkenyl thiazolones
作者:Yong-Xing Song、Da-Ming Du
DOI:10.1039/c9ob00998a
日期:——
An efficient and practical organocatalyzed asymmetric formal [2 + 1] cycloaddition of 3-chlorooxindoles with 5-alkenyl thiazolones by using hydroquinine-derived squaramide as the catalyst has been developed. Under mild conditions, a broad range of spirooxindole-fused spirothiazolones bearing three adjacent stereogenic centers including two vicinal spiro quaternary chiral centers were obtained in high