Phosphine-Catalyzed Annulations Based on [3+3] and [3+2] Trapping of Ketene Intermediates with Thioamides
作者:Yu-Hao Wang、Zhen-Ni Zhao、Subarna Jyoti Kalita、Yi-Yong Huang
DOI:10.1021/acs.orglett.1c02803
日期:2021.11.5
With the aim of developing novel annulations via ketene intermediates, allenyl imide and alkynoates bearing good leaving groups are used for their function in a tandem conjugate addition–elimination reaction (SN2′ type) promoted by nucleophilic phosphine catalysts. By utilizing thioamides as 1S,3N-bis-nucleophiles, [3+3] and [3+2] annulations have been established to allow rapid access to 1,3-thiazin-4-ones
为了通过乙烯酮中间体开发新的环化反应,具有良好离去基团的烯丙酰亚胺和炔酸酯被用于在亲核膦催化剂促进的串联共轭加成-消除反应(SN2'型)中发挥作用。通过利用硫代酰胺作为 1 S ,3 N-双亲核试剂,已建立 [3+3] 和 [3+2] 环化,以允许在高浓度条件下快速获得 1,3-噻嗪-4-酮和 5-烯基噻唑酮产量,分别。此外,在氘标记实验和密度泛函理论计算的基础上,提出了可能的反应机理。