A highlyefficient synthesis of novel spirocyclic benzoxazine‐indenes from benzoxazine and alkynes via iminedirected C–H activation/annulation using rhodium catalyst was reported. The methodology could be applied to various benzoxazines and alkynes, giving the corresponding spiro indenyl benzoxazine as spirocycle products in good yields.
Highly Enantioselective SPINOL-Derived Phosphoric Acid Catalyzed Transfer Hydrogenation of Diverse C=N-Containing Heterocycles
作者:Yiliang Zhang、Rong Zhao、Robert Li-Yuan Bao、Lei Shi
DOI:10.1002/ejoc.201500330
日期:2015.5
A highly efficient and enantioselectivehydrogenation of diversely substituted C=N-containing heterocyclic compounds such as 3-aryl-1,4-benzoxazines and 2-arylquinolines was experimentally explored by using 1,1′-spirobiindane-7,7′-diol-derived chiral phosphoric acids as the catalyst. This method provides straightforward access to the corresponding tetrahydroquinolines and dihydro-2H-1,4-benzothiazines
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.
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Promoted hydrogenations of N-heterocycles with ammonia borane
作者:Fangwei Ding、Yiliang Zhang、Rong Zhao、Yanqiu Jiang、Robert Li-Yuan Bao、Kaifeng Lin、Lei Shi
DOI:10.1039/c7cc04709f
日期:——
A transition-metal-free method for the B(C6F5)3-promoted hydrogenations of N-heterocycles using ammonia borane under mild reaction conditions has been developed. The reaction affords a broad range of hydrogenated products in moderate to good yields. The enantioselective versions for the corresponding products were also investigated via our approach, showing good feasibility.
已开发出一种无过渡金属的方法,该方法使用硼烷氨在温和的反应条件下进行B(C 6 F 5)3促进的N-杂环加氢反应。该反应以中等至良好的产率提供了广泛的氢化产物。还通过我们的方法对相应产品的对映选择性进行了研究,显示出良好的可行性。