使用(环辛二烯)铱氯化二聚物/(S)-SegPhos /碘{[Ir(COD)Cl] 2 /(S)-SegPhos实现对3-芳基2 H -1,4-苯并恶嗪的高度对映选择性氢化/ I 2 }体系作为催化剂,ee最高可达92%。3-styryl-2 H -1,4-苯并恶嗪衍生物还通过铱催化剂和Pd / C在两个连续的步骤中进行氢化,从而获得93-95%ee值。
Remarkable Ligand Effect on Rh-Catalyzed C–H-Active [3 + 2] Annulation of Ketimines and Alkynes
作者:Yan Shi、Yong Fang、Xu Zhao、Chengfeng Zhu、Xiang Wu、Xiaoming Yang、Yunfei Luo
DOI:10.1021/acs.orglett.0c01768
日期:2020.6.19
Externally added ligands were first found to have a significant impact on the Rh-catalyzed C–H-active [3 + 2] annulation of ketimines and alkynes. Olefin ligands have shown remarkable promotion effect for this reaction. The olefin promoted the reaction by increasing both the turnover rate and conversion of [Cp*RhCl2]2 in the formation of rhodacycle in the C–H activation step.
Rh-Catalyzed [3+2] Annulation of Cyclic Ketimines and Alkynyl Chloride: A Strategy for Accessing Unsymmetrically Substituted and Highly Functionalizable Indenes
作者:Xu Zhao、Chenrui Fan、Jianbo He、Yunfei Luo
DOI:10.1021/acs.orglett.2c02717
日期:2022.12.23
Alkynyl chlorides were found to be extraordinarily novel electrophiles, which could afford a single regioisomer of the [3+2] annulation adducts with cyclic ketimines by rhodium catalysis. The alkenyl chloride moiety in the products provided a valuable functional handle for further diverse transformations. Therefore, this research provided not only a synthetic protocol for accessing unsymmetrically
synthesis of novel spirocyclic β2,3,3-amino acids, is reported. This approach shows wide substrate scope of CF3-ynones and ketimines. In addition, several natural products and biologically relevant molecules, prepared by this method, can be further functionalized. Novel dipeptide and tripeptide structures can be successfully assembled with this spirocyclic amino acid.