Developing greener synthetic processes is an inescapable necessity to transform the industrial landscape, mainly in the pharmaceutical sector, into a long-term, sustainable reality. In this context, the renaissance of peptides...

Targeting protein-protein interactions (PPIs) has been recently recognized as an emerging therapeutic approach for several diseases. Up today, more than half a million PPI dysregulations have been found to be involved in pathological events. The dynamic nature of these processes and the involvement of large protein surfaces discouraged anyway the scientific community in considering them promising therapeutic targets. More recently peptide drugs received renewed attention since drug discovery has offered a broad range of structural diverse sequences, moving from traditionally endogenous peptides to sequences possessing improved pharmaceutical profiles. About 70 peptides are currently on the marked but several others are in clinical development. In this review we want to report the update on these novel APIs, focusing our attention on the molecules in clinical development, representing the direct consequence of the drug discovery process of the last 10 years. The comprehensive collection will be classified in function of the structural characteristics (native, analogous, heterologous) and on the basis of the therapeutic targets. The mechanism of interference on PPI will also be reported to offer useful information for novel peptide design.

The replacement of toxic solvents with greener alternatives in Heck–Cassar–Sonogashira (HCS) cross-couplings was investigated. The fine-tuning of the HCS protocol allowed to achieve complete conversions and high speed under mild conditions. N -Hydroxyethylpyrrolidone (HEP) gave the best results. Moreover, the methodology was successfully applied to the synthesis of an intermediate of the anticancer drug Erlotinib, demonstrating the versatility of the new green protocol.

The identification of a green, versatile, user‐friendly, and efficient methodology is necessary to facilitate the use of Heck‐Cassar‐Sonogashira (HCS) cross‐coupling reaction in drug discovery and industrial production in the pharmaceutical segment. The Heck‐Cassar and Sonogashira protocols, using N‐hydroxyethylpyrrolidone (HEP)/water/N,N,N′,N′‐tetramethyl guanidine (TMG) as green solvent/base mixture and sulfonated phosphine ligands, allowed to recycle the catalyst, always guaranteeing high yields and fast conversion under mild conditions, with aryl iodides, bromides, and triflates. No catalyst leakage or metal contamination of the final product were observed during the HCS recycling. To our knowledge, a turnover number (TON) up to 2375, a turnover frequency (TOF) of 158 h−1, and a process mass intensity (PMI) around 7 that decreased around 3 after solvent, base, and palladium recovery, represent one of the best results to date using a sustainable protocol. The Heck‐Cassar protocol using sSPhos was successfully applied to the telescoped synthesis of Erlotinib (TON: 1380; TOF: 46 h−1).

A green protocol for SPPS allows the recovery and recycling of solvents and bases from the process waste mixture.