Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA.
Nat Chem. 2010 Jan;2(1):30-5. doi: 10.1038/nchem.477. Epub 2009 Dec 13.
Molecular nitrogen (N(2)) and carbon monoxide (CO) have the two strongest bonds in chemistry and present significant challenges in developing new transformations that exploit these two abundant feedstocks. At the core of this objective is the discovery of transition-metal compounds that promote the six-electron reductive cleavage of N(2) at ambient temperature and pressure and also promote new nitrogen-element bond formation. Here we show that an organometallic hafnium compound induces N(2) cleavage on the addition of CO, with a simultaneous assembly of new nitrogen-carbon and carbon-carbon bonds. Subsequent addition of a weak acid liberates oxamide, which demonstrates that an important agrochemical can be synthesized directly from N(2) and CO. These studies introduce an alternative paradigm for N(2) cleavage and functionalization in which the six-electron reductive cleavage is promoted by both the transition metal and the incoming ligand, CO, used for the new bond formations.
分子氮（N2）和一氧化碳（CO）具有化学中最强的两个键，因此在开发利用这两种丰富原料的新转化方面存在重大挑战。这一目标的核心是发现能够促进在环境温度和压力下六电子还原裂解 N2 的过渡金属化合物，同时也促进新的氮-元素键形成。在这里，我们表明，有机金属铪化合物在添加 CO 时会诱导 N2 裂解，同时形成新的氮-碳和碳-碳键。随后加入弱酸可释放出草酰胺，这表明可以直接从 N2 和 CO 合成重要的农用化学品。这些研究为 N2 裂解和功能化引入了一种替代范式，其中六电子还原裂解既由过渡金属又由引入的配体 CO 促进，CO 用于形成新的键。
