EaStCHEM School of Chemistry, University of Edinburgh , Joseph Black Building, David Brewster Road, Edinburgh, Scotland U.K. , EH9 3FJ.
J Am Chem Soc. 2018 Feb 28;140(8):2862-2868. doi: 10.1021/jacs.7b12146. Epub 2018 Feb 13.
The Diels-Alder (DA) reaction is a cornerstone of synthesis, yet Nature does not use catalysts for intermolecular [4+2] cycloadditions. Attempts to create artificial "Diels-Alderases" have also met with limited success, plagued by product inhibition. Using a simple PdL capsule we now show DA catalysis that combines efficient turnover alongside enzyme-like hallmarks. This includes excellent activity (k/k > 10), selective transition-state stabilization comparable to the most proficient DA catalytic antibodies, and control over regio- and chemoselectivity that would otherwise be difficult to achieve using small-molecule catalysts. Unlike other catalytic approaches that use synthetic capsules, this method is not defined by entropic effects; instead multiple H-bonding interactions modulate reactivity, reminiscent of enzymatic action.
Diels-Alder（DA）反应是合成的基石，但自然界并不使用催化剂进行分子间[4+2]环加成反应。创造人工“Diels-Alderases”的尝试也取得了有限的成功，但受到产物抑制的困扰。现在，我们使用一种简单的 PdL 胶囊展示了 DA 催化，它结合了高效的周转率和酶样特征。这包括出色的活性（k/k > 10）、与最有效的 DA 催化抗体相当的选择性过渡态稳定，以及对区域和化学选择性的控制，使用小分子催化剂很难实现。与使用合成胶囊的其他催化方法不同，这种方法不受熵效应的限制；相反，多个氢键相互作用调节反应性，类似于酶的作用。
