State Key Laboratory of Organometallic Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Ling-Ling Lu, Shanghai, 200032, China.
Chem Commun (Camb). 2022 Sep 1;58(71):9926-9929. doi: 10.1039/d2cc03635e.
A new method for the synthesis of azaaromatic vinylcyclopropanes (VCPs) has been disclosed in this paper by using pyrrole or indole derivatives as nucleophilic reagents to react with vinylidenecyclopropane-diesters (VDCP-diesters) in the presence of a Pd catalyst, a phosphine ligand and a base under mild conditions in up to 98% yield with a reasonable substrate scope. This reaction is one of the few examples of hydroamination at electron-rich allene's β-position. A plausible reaction mechanism has also been proposed through a zwitterionic π-propargyl -palladium species according to the previous work and the obtained deuterium labeling experimental result.
本文报道了一种使用吡咯或吲哚衍生物作为亲核试剂，在钯催化剂、膦配体和碱的存在下，于温和条件下与乙烯基环丙二酯（VDCP-二酯）反应，以高达 98%的收率和合理的底物范围合成氮杂芳基乙烯基环丙烷（VCPs）的新方法。该反应是富电子丙二烯β位氢胺化的少数几个例子之一。根据之前的工作和获得的氘标记实验结果，通过两性离子π-丙炔基-钯物种提出了一个合理的反应机理。
