A convenient preparative protocol for the synthesis of various 3-arylcyclopropenes in a multigram, scale is disclosed. Optimization of the reaction conditions and isolation procedures allowed for significant improvement of the chemical yields of these strained products. The described protocol was used for efficient preparation of a series of 3-methyl-3-arylcyclopropenes possessing different substituents in the aromatic ring. The effect of substitution in the aryl group on the stability of 3-arylcyclopropenes, as well as the corresponding precursors, is discussed. (c) 2008 Elsevier Ltd. All rights reserved.
[(NHC)Ni
<sup>II</sup>
H]‐Catalyzed Cross‐Hydroalkenylation of Cyclopropenes with Alkynes: Cyclopentadiene Synthesis by [(NHC)Ni
<sup>II</sup>
]‐Assisted C−C Rearrangement
作者:Jian‐Qiang Huang、Chun‐Yu Ho
DOI:10.1002/anie.201901255
日期:2019.4.16
achieved for the first time by using new [(NHC)Ni(allyl)]BArF catalysts (NHC=N‐heterocyclic carbenes). By controlling the (NHC)NiIIH relative insertion reactivity with cyclopropene and alkyne, a broad scope of cyclopentadienes was obtained with highly selectively. The structural features of the new (NHC)NiII catalyst were important for the success of the reaction. The mild reaction conditions employed may
通过使用新的[(NHC)Ni(烯丙基)] BAr F催化剂(NHC = N杂环卡宾),首次使用环丙烯和炔烃作为底物对实现了交叉氢烯基化/重排级联反应(HARC )。通过控制(NHC)Ni II H与环丙烯和炔烃的相对插入反应性,可以高度选择性地获得宽范围的环戊二烯。新型(NHC)Ni II催化剂的结构特征对于反应成功至关重要。所采用的温和反应条件可以作为探索(NHC)Ni II辅助的乙烯基环丙烷重排反应性的入口。