As I already wrote in my previous post, we at Enamine are constantly working on extending our REAL concept (where REAL is for REadily AccessibLe compounds). Basically, this concept allows for the generation of a virtual chemical space based on the experimentally validated synthetic accessibility. Until now the REAL Space has comprised 15.5 billion make-on-demand molecules and is currently the largest offer of commercially available compounds. It was shown that this chemical space is especially useful in combination with high-throughput virtual screening techniques (see Nature 2019, 566, 224–229 and Nature 2020, 580, 663–668); there is also a number of other ways to access it.
In a new paper just published in European Journal of Organic Chemistry, we for the first time describe application of the REAL principles to the generation of artificial macrocycle libraries. A very simple and robust chemistry based on the "build‐couple‐pair" diversity‐oriented (DOS) strategy was used to construct a virtual library of 180,000 macrocycles derived from 12,283 different scaffolds. The approach showed a 61% success rate under the parallel synthesis conditions, which is a very good result for the 4–5‐step reaction sequence including two chromatographic purifications. More than 40% compounds from the Macro Space bear an amino function suitable for the post‐pairing modification, thus giving a rise to at least a billion‐sized chemical space, as well as macrocyclic building blocks available on a gram scale.
See the full paper for more details.
Examples of macrocycles