Development of Dual Transition Metal Activation for Methane and Carbon Dioxide and further Processing to Carbamate Formation

甲烷和二氧化碳是两种化合物，它们的特点是对过渡金属的活化相对惰性。但在一定的反应条件下，分子催化剂的配位球内可以发生转化。本文提出了一种新的、经济的以常见散装原料甲烷、二氧化碳和胺为原料催化合成氨基甲酸酯类精细化学品的方法。氨基甲酸酯类产品是重要的、用途广泛的氮源，应用于制药、医学和生物研究的有机合成中。因此，完成拟议的工作应对欧洲工业和学术研究的各个领域产生影响。整个反应预测甲烷在过渡金属配合物内的活化反应，其次是胺配位和二氧化碳插入反应。氨基甲酸酯产物将通过一种新的还原消除产生，基本上没有任何副产物的形成。因此，与目前采用的涉及光气和醇的程序相比，总体顺序将构成一个有利的过程。关键问题是所有步骤的高选择性的发展。这只能通过适当调整过渡金属中心的反应性并结合合适的配体支架来实现。所提出的方法的优点在于所有单个化合物的独立合成相对容易。因此，应该有可能通过理论和实验以互补的方式优化每个单独的步骤。然后，这两个小组将共同为这一新的转变建立一个催化循环。

Methane and carbondioxide represent two compounds, which are characterised by their relative inertness to transition metal activation. However, under certain reaction conditions, transformation within the coordination sphere of molecular catalysts can be accomplished. We here propose a novel, economic catalytic synthesis of carbamate fine chemicals from the common bulk materials methane, carbondioxide and amines. The carbamate products represent important and versatile nitrogen sources as applied in organic synthesis for pharmaceutical, medicinal and biological research. Accomplishment of the proposed work should therefore have an impact on various European areas of industrial and academic research. The overall reaction foresees an activation reaction of methane within a transition metal complex, followed by amine coordination and carbondioxide insertion reaction. The carbamate product will be generated by a novel reductive elimination, essentially without any side-product formation. The overall sequence will hence constitute an advantageous process in comparison to the currently employed procedure, which involves phosgene and alcohols.Key issues refer to the development of high selectivity for all steps. This can only be accomplished through appropriately tuning the reactivity of the transition metal centre in combination with a suitable ligand scaffold. The advantage of the presented approach lies in an expected relative ease of independent synthesis for all individual compounds. Hence, it should be possible to optimise each of the individual steps both by theory and by experiment in a complementary fashion. The two groups will then jointly arrive at the establishment of a catalytic cycle for this new transformation.