Bhat Avinash S, Elbert Sven M, Zhang Wen-Shan, Rominger Frank, Dieckmann Michael, Schröder Rasmus R, Mastalerz Michael
Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 270, 69120, Heidelberg, Germany.
Centre for Advanced Materials, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 225, 69120, Heidelberg, Germany.
Angew Chem Int Ed Engl. 2019 Jun 24;58(26):8819-8823. doi: 10.1002/anie.201903631. Epub 2019 May 17.
In recent years, interest in shape-persistent organic cage compounds has steadily increased, not least because dynamic covalent bond formation enables such structures to be made in high to excellent yields. One often used type of dynamic bond formation is the generation of an imine bond from an aldehyde and an amine. Although the reversibility of the imine bond formation is advantageous for high yields, it is disadvantageous for the chemical stability of the compounds. Amide bonds are, in contrast to imine bonds much more robust. Shape-persistent amide cages have so far been made by irreversible amide bond formations in multiple steps, very often accompanied by low yields. Here, we present an approach to shape-persistent amide cages by exploiting a high-yielding reversible cage formation in the first step, and a Pinnick oxidation as a key step to access the amide cages in just three steps. These chemically robust amide cages can be further transformed by bromination or nitration to allow post-functionalization in high yields. The impact of the substituents on the gas sorption behavior was also investigated.
近年来，人们对形状持久的有机笼状化合物的兴趣稳步增长，这尤其是因为动态共价键的形成使得此类结构能够以高至优异的产率制备。一种常用的动态键形成类型是由醛和胺生成亚胺键。尽管亚胺键形成的可逆性有利于高产率，但对化合物的化学稳定性不利。与亚胺键相比，酰胺键要稳定得多。到目前为止，形状持久的酰胺笼是通过多步不可逆的酰胺键形成制备的，产率往往很低。在此，我们提出了一种制备形状持久酰胺笼的方法，第一步利用高产率的可逆笼状结构形成，然后以品尼克氧化作为关键步骤，只需三步就能得到酰胺笼。这些化学性质稳定的酰胺笼可以通过溴化或硝化进一步转化，以实现高产率的后官能化。还研究了取代基对气体吸附行为的影响。
