Instant Macrocyclizations via Multicomponent Reactions.

Macrocycles fascinate chemists due to both their structure and their applications. However, we still lack efficient and sustainable synthetic methods, giving us straightforward access to them. Herein, a rapid macrocyclization utilizing a two-step, one-pot approach based on orthogonal multicomponent reaction (MCR) tactics is introduced. This synthetic protocol, which is based on Ugi and Groebke-Blackburn-Bienaymé reactions with isocyanides tethered to alkyl tosylates, yields medium sized macrocycles that are otherwise difficult to achieve. Single crystal structures reveal conformational reorganization via intramolecular hydrogen bonding, and modeling studies profile the synthesized libraries.

New oxacycles on the block: benzodioxepinones via a Passerini reaction.

Oxacycles and benzoxepanes are privileged motifs present in a variety of natural products and functional molecules. However, their synthetic access is limited. Here, we demonstrate a rapid synthesis of unprecedented benzoxepanes from readily available starting materials in one step via a Passerini multicomponent reaction. The reaction proceeds smoothly under mild reaction conditions. We have obtained a single-crystal X-ray structure, revealing a butterfly conformation, combined with useful structural features. In addition, we have performed both a full interaction map on the X-ray structure and a profile analysis of a virtual library based on the proposed scaffold with a special focus on certain physicochemical parameters to demonstrate their potential usage in drug discovery.