Stimuli-responsive dendrimers. Towards tunable catalysts (DENDSWITCH)

催化是一种进行化学转化的独特工具，实验参数的细微变化可以对催化反应的结果产生巨大影响。树突状催化剂具有将均相和非均相催化剂的优点和缺点结合起来的潜力。事实上，它们可溶于溶剂，但它们具有大量明确的催化位点，并且由于它们的大尺寸，它们可以很容易地从产物中分离（和重复使用）。已经提出了几种树突催化剂，说明了这一研究领域日益增长的重要性。然而，到目前为止，很少或根本没有利用树突催化剂对催化的整个部分进行探索。这尤其适用于使用“可切换”（刺激响应）催化剂的情况，这种催化剂由温度、光、pH或电化学驱动，其中外部刺激将用于改变立体（咬角、立体需求）和/或电子（σ-供体/π-受体）性质或诱导半可降解行为。它们在随意改变催化活性和关闭或激活催化剂以触发催化事件方面的应用将受到仔细审查。

Catalysis is a unique tool to carry out chemical transformations, and it is well established that subtle changes in experimental parameters could have a dramatic effect on the outcome of catalytic reactions. Dendritic catalysts have the potential for combining the advantages and minimizing the disadvantages of homogeneous and heterogeneous catalysts. Indeed, they are soluble in solvents, but they possess a large and well-defined number of catalytic sites and they can be easily separated from the products (and reused) due to their large size. Several dendritic catalysts have been proposed already, illustrating the growing importance of this field of research. However, whole sections of catalysis have been scarcely or not at all explored up to now using dendritic catalysts. This is in particular the case for using “switchable” (stimuli-responsive) catalysts, which are driven by temperature, light, pH, or electrochemically, where the external stimulus will be used to vary the steric (bite angle, steric demand) and/or electronic (σ-donor/π-acceptor) properties or to induce hemilabile behavior. Their application to change catalytic activity at will and shut down or activate catalysts to trigger catalytic events will be scrutinized.