Peptidomimetics medium-sized

This review will focus on the use of MCR approaches to cyclic peptides, cyclic peptidomimetics, or cyclic pseudopeptides, including small or medium-sized heterocycles as mimics of peptide motifs and macrocycles with amino acid or peptide moieties. 

Several groups tried to access medium-sized rings (ca. 8-12 membered) with peptide-like moieties. Most prominent is the I-MCR/RCM strategy [15, 16], As shown in Scheme 11. 12-Memhered cyclic peptidomimetics were reported hy Oikawa and co-workers who used initial Ugi-4CRs performed in excellent yields, followed hy functionalization of the resulting Ugi-platform to introduce the desired alkene functionalities [65]. RCM with the second generation Hoveyda-Gruhhs... 

Naturally occurring peptides are substrates of enzymes and ligands of receptors. Many peptides serve as neurotransmitters and hormones. Because they control a variety of physiological processes, they are also implicated in different diseases. For several reasons peptides are usually unsuitable as drugs, so many efforts in medicinal chemistry aim at the development of peptidomimetics with improved properties. In contrast with proteins most peptides of small to medium size - 30 to... 

The formation of medium size rings (8-10-membered) presents challenges based on strain and entropy (Scheme Reitz utilized RCM by (2a) of diallyl glycine to give the eight-membered cyclic olefin in equation (45). Two steps convert it to a scaffold for peptidomimetic synthesis. 

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