This Review is devoted to the chemistry of macrocyclic peptides having heterocyclic fragments in their structure. These motifs are present in many natural products and synthetic macrocycles designed against a particular biochemical target. Thiazole and oxazole are particularly common constituents of naturally occurring macrocyclic peptide molecules. This frequency of occurrence is because the thiazole and oxazole rings originate from cysteine, serine, and threonine residues. Whereas other heteroaryl groups are found less frequently, they offer many insightful lessons that range from conformational control to receptor/ligand interactions. Many options to develop new and improved technologies to prepare natural products have appeared in recent years, and the synthetic community has been pursuing synthetic macrocycles that have no precedent in nature. This Review attempts to summarize progress in this area.

Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n→π* orbital delocalisation. Here these observations are reconciled. A combined experimental and computational approach confirmed the dominance of electrostatic interactions in a new series of synthetic molecular balances, while also highlighting the distance‐dependent observation of inductive polarisation manifested by n→π* orbital delocalisation. Computational fiSAPT energy decomposition and natural bonding orbital analyses correlated with experimental data to reveal the contexts in which short‐range inductive polarisation augment electrostatic dipolar interactions. Thus, we provide a framework for reconciling the context dependency of the dominance of electrostatic interactions and the occurrence of n→π* orbital delocalisation in C=O⋅⋅⋅C=O interactions.

Oxidative addition and reductive elimination are defining reactions of transition-metal organometallic chemistry. In main-group chemistry, oxidative addition is now wellestablished but reductive elimination reactions are not yet general in the same way. Herein, we report dihydrodialanes supported by amidophosphine ligands. The ligand serves as a stereochemical reporter for reversible reductive elimination/ oxidative addition chemistry involving Al I and Al III intermediates.

A new efficient synthetic route to 4‐fluoro‐5‐aryl‐1,2,3‐NH‐triazoles was elaborated. The reactions of NaN3 with aryl‐substituted α‐fluoronitroalkenes resulted in the domino construction of the target fluorinated triazoles. Sulfamic acid is an effective promoter for this heterocyclization. The subsequent functionalization reactions of the obtained triazoles proceed highly regioselectively at the N‐2 position. The observed regioselectivity was supported by DFT calculations.

Interactions between carbonyl groups are prevalent in protein structures. Earlier investigations identified dominant electrostatic dipolar interactions, while others implicated lone pair n→π* orbital delocalisation. Here these observations are reconciled. A combined experimental and computational approach confirmed the dominance of electrostatic interactions in a new series of synthetic molecular balances, while also highlighting the distance‐dependent observation of inductive polarisation manifested by n→π* orbital delocalisation. Computational fiSAPT energy decomposition and natural bonding orbital analyses correlated with experimental data to reveal the contexts in which short‐range inductive polarisation augment electrostatic dipolar interactions. Thus, we provide a framework for reconciling the context dependency of the dominance of electrostatic interactions and the occurrence of n→π* orbital delocalisation in C=O⋅⋅⋅C=O interactions.