Modular Bi-Directional One-Pot Strategies for the Diastereoselective Synthesis of Structurally Diverse Collections of Constrained ß-Carboline-Benzoxazepines.

The development of robust and efficient strategies to access structurally diverse drug-like compound collections remains an important challenge for small molecule probe development and drug discovery. Following a build/couple/pair strategy we have established bidirectional approach to unprecedented benzoxazepines by employing a Pictet-Spengler/aza-Michael addition cascade and Schiff base/aza-Michael addition/reduction protocols, respectively. The corresponding ß-carboline-fused benzoxazepines and peripherally substituted benzoxazepines are isolated in high diastereoselectivity, good to excellent yields and have, to the best of our knowledge, never been reported.

Intramolecular Diaza-Diels-Alder Protocol: A New Diastereoselective and Modular One-Step Synthesis of Constrained Polycyclic Frameworks.

Phenotype-based screening of diverse compound collections generated by privileged substructure-based diversity-oriented synthesis (pDOS) is considered one of the prominent approaches in the discovery of novel drug leads. However, one key challenge that remains is the development of efficient and modular synthetic routes toward the facile access of privileged small-molecule libraries with skeletal and stereochemical complexity and drug-like properties. In this regard, a novel and diverse one-pot procedure for the diastereoselective synthesis of privileged polycyclic benzopyrans and benzoxepines is described herein. These unexplored chemotypes were accessed by utilizing an acid-mediated diaza-Diels-Alder reaction of 2-allyloxy- and/or homoallyloxy benzaldehyde with 2-aminoazine building blocks. Profiling of representative analogues against blood-stage Plasmodium falciparum parasites identified three lead candidates with low micromolar antimalarial activity.