A Convergent Synthesis Approach to Uranium-Carbon Triple Bonds for Alkyne Metathesis Reactions.

在过渡金属化学中，烷基炔配合物因其在炔复分解催化中所起的作用而引起人们的兴趣。最著名的炔复分解反应催化剂的分子式为RC≡M(OR)3, M = Mo， W，是商业上可用的化合物，最初是由R. Schrock发现的。康明斯集团在炔转化方面经验丰富，并做出了贡献。结果表明，式R1C≡Mo(N[i-Pr]Ar)3的配合物是“通用”的催化剂前体，因为它们与3r2oh处理后产生式R1C≡Mo(OR2)3的活性炔转化催化剂。迈耶研究计划的一个主要组成部分是活化活性铀复合物中的小分子。这些配合物具有可用于反应化学的立体保护单结合位点。这项工作的一个亮点是通过单一的氧-铀相互作用（η - 1- o - co2）结合和活化二氧化碳。对于本文提出的研究，我们将tacan -三酚酸铀平台与康明斯早期过渡金属试剂相结合，体现了“聚合合成”的原则。这一聚合努力的目的是发现第一个铀烷基炔（U≡CR）配合物并探测它们在炔复分解中的活性。

In transition-metal chemistry, alkylidyne complexes are of interest for the role that they play in alkyne metathesis catalysis. The best-known catalysts for the alkyne metathesis reaction have the formula RC≡M(OR)3 with M = Mo, W, are commercially available compounds, and were originally discovered by R. Schrock. The Cummins group is experienced with and has made contributions to alkyne metathesis. It was shown that complexes of the formula R1C≡Mo(N[i-Pr]Ar)3 are “universal” catalyst precursors, because their treatment with 3 R2OH produces active alkyne metathesis catalysts of formula R1C≡Mo(OR2)3. A major component of the Meyer research program is the activation of small molecules at reactive uranium complexes. These complexes have a sterically protected single binding site available for reaction chemistry. A highlight of this work has been the binding and activation of carbon dioxide through a single oxygenuranium interaction (η1-O-CO2). For the research proposed herein, the principle of “convergent synthesis” is embodied by our combination of the tacn-triphenolate uranium platform with Cummins’ early transition-metal reagents. The aim of this convergent effort is to uncover the first uranium alkylidyne (U≡CR) complexes and to probe their activity in alkyne metathesis.