美国明尼苏达大学Hoye, Thomas R.团队报道了从互补配对的炔中制备游离的碳烯。相关研究成果发表在2024年6月25日出版的《自然—化学》。

碳烯（R¹R²C:）类自由基、芳基和硝基构成了一个重要的中性、高能、反应性中间体家族，这些中间体是经过快速反应的短暂化学实体。炔烃（R³C≡CR⁴）是一个基本的官能团，具有很高的势能；然而，炔烃具有显著的动力学稳定性，使其能够方便地作为货架稳定的化学商品进行处理。由炔烃的高势能（即热力学）提供燃料，直接从炔烃中产生无金属碳烯的能力将是一个相当大的进步。

该文中，研究发现，这可以简单地通过加热2-炔基亚氨基杂环（一种含有亲核氮原子的环状化合物）与亲电炔烃的混合物来实现。研究人员证明了该过程的相当普遍性：许多货架稳定的炔烃亲电试剂与许多类别的（2-炔基）杂环亲核试剂接触，产生卡宾中间体，这些中间体立即经历许多类型的转化，从而提供了获得各种杂环产物的简便实用的途径。研究人员描述了反应的关键机制方面。

附：英文原文

Title: Free carbenes from complementarily paired alkynes

Author: Xu, Qian, Hoye, Thomas R.

Issue&Volume: 2024-06-25

Abstract: Carbenes (R1R2C:) like radicals, arynes and nitrenes constitute an important family of neutral, high-energy, reactive intermediates—fleeting chemical entities that undergo rapid reactions. An alkyne (R3C≡CR4) is a fundamental functional group that houses a high degree of potential energy; however, the substantial kinetic stability of alkynes renders them conveniently handleable as shelf-stable chemical commodities. The ability to generate metal-free carbenes directly from alkynes, fuelled by the high potential (that is, thermodynamic) energy of the latter, would constitute a considerable advance. We report here that this can be achieved simply by warming a mixture of a 2-alkynyl iminoheterocycle (a cyclic compound containing a nucleophilic nitrogen atom) with an electrophilic alkyne. We demonstrate considerable generality for the process: many shelf-stable alkyne electrophiles engage many classes of (2-alkynyl)heterocyclic nucleophiles to produce carbene intermediates that immediately undergo many types of transformations to provide facile and practical access to a diverse array of heterocyclic products. Key mechanistic aspects of the reactions are delineated.

DOI: 10.1038/s41557-024-01550-9

Source: https://www.nature.com/articles/s41557-024-01550-9