德国慕尼黑工业大学Inoue Shigeyoshi团队报道了NHC稳定的重腈的分离及其转化为异腈类似物。相关研究成果发表在2024年9月10日出版的《自然—化学》。

腈（R-C≡N）自十八世纪末以来一直被研究，在有机和无机合成中无处不在。相比之下，含有碳和氮的较重类似物的较重腈是研究较少的物种。

该文中，研究人员报告了一种膦基亚硅烯的合成和分离，其特征是N-杂环卡宾亚膦基和高度空间要求的甲硅烷基作为取代基。由于其独特的结构基序，它可以被视为路易斯碱稳定的较重腈。

Si-P键显示出多重键特征和弯曲的R-Si-P几何形状，后者表明较重腈和经典腈之间存在根本差异。在溶液中，会发生亚膦的定量异常重排。这种重排与从较重的腈到较重的异腈的重排的理论预测是一致的。

初步反应性研究表明，这两种异构体都表现出高度亲核的硅中心，能够与四羰基铁进行氧化加成和配位。

附：英文原文

Title: Isolation of a NHC-stabilized heavier nitrile and its conversion into an isonitrile analogue

Author: Doleschal, Martin E., Kostenko, Arseni, Liu, Jin Yu, Inoue, Shigeyoshi

Issue&Volume: 2024-09-10

Abstract: Nitriles (R–C≡N) have been investigated since the late eighteenth century and are ubiquitous encounters in organic and inorganic syntheses. In contrast, heavier nitriles, which contain the heavier analogues of carbon and nitrogen, are sparsely investigated species. Here we report the synthesis and isolation of a phosphino-silylene featuring an N-heterocyclic carbene-phosphinidene and a highly sterically demanding silyl group as substituents. Due to its unique structural motif, it can be regarded as a Lewis base-stabilized heavier nitrile. The Si–P bond displays multiple bond character and a bent R–Si–P geometry, the latter indicating fundamental differences between heavier and classical nitriles. In solution, a quantitative unusual rearrangement to a phosphasilenylidene occurs. This rearrangement is consistent with theoretical predictions of rearrangements from heavier nitriles to heavier isonitriles. Our preliminary reactivity studies revealed that both isomers exhibit highly nucleophilic silicon centres capable of oxidative addition and coordination to iron tetracarbonyl.

DOI: 10.1038/s41557-024-01618-6

Source: https://www.nature.com/articles/s41557-024-01618-6