Synthesis of 7<i>H</i>-Benzo[<i>e</i>]naphtho[1,8-<i>bc</i>]silines by Rhodium-catalyzed [2 + 2 + 2] Cycloaddition
作者:Takumi Maesato、Ryo Shintani
DOI:10.1246/cl.200025
日期:2020.4.5
An efficient synthesis of 7H-benzo[e]naphtho[1,8-bc]silines has been developed by a rhodium-catalyzed [2 + 2 + 2] cycloaddition of alkynyl(8-alkynyl-1-naphthyl)silanes with internal alkynes. High c...
a selective phosphoranation of alkynes with phosphoniumcation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols
The electrochemical three‐componentassembly of isoquinolines has been accomplished by ruthenaelectro‐catalyzed C−H/N−H functionalization. The robustness of the electrocatalysis was reflected by an ample substrate scope, an efficient electrooxidation, and an operationally friendly procedure. The isolation of key intermediates and detailed mechanistic studies, including unprecedented cyclovoltammetric
异喹啉的电化学三组分组装已通过钌电子催化的CH / NH官能团完成。电催化的坚固性通过足够的底物范围,有效的电氧化作用和操作友好的程序得以体现。关键中间体的分离和详细的机理研究,包括对七元钌循环的前所未有的循环伏安分析,为不寻常的钌(II / III / I)机制提供了支持。
Enantioselective Twofold C−H Annulation of Formamides and Alkynes without Built‐in Chelating Groups
作者:Hao Chen、Yin‐Xia Wang、Yu‐Xin Luan、Mengchun Ye
DOI:10.1002/anie.202001267
日期:2020.6.8
Twofold C−H annulation of readily available formamides and alkynes without built‐in chelatinggroups was achieved. Ni−Al bimetallic catalysis enabled by a bulky BINOL‐derived chiral secondary phosphine oxide (SPO) ligand proved to be critical for high reactivity and high selectivity. This reaction uses readily available formamides as starting materials and provides a concise synthetic pathway to a
Copper catalyzed/mediated direct B–H alkenylation/alkynylation in carboranes
作者:Yu Chen、Yik Ki Au、Yangjian Quan、Zuowei Xie
DOI:10.1007/s11426-018-9388-3
日期:2019.1
B–H functionalization has been achieved. Under the assistance of a bidentate directing group, Cu-catalyzed [4+2] annulation of carboranyl amides with internal alkynes affords unprecedented C,B-substituted carborane-fused-pyridone derivatives, whereas the use of terminal alkynes leads to B–H/C(sp)–H dehydrocoupling products. The isolation and structural identification of a notably stable Cu(I) intermediate