PyBroP is a phosphonium salt used in peptide coupling chemistry, similar to PyCloP[1]. PyBroP has the advantages of high efficiency, high yield, no diastereoisomerization and fast reaction rate in the coupling of N-methylated amino acids and α,α-disubstituted amino acids[2]. PyBroP is a derivative of the phosphonium coupling reagent BOP, but contains pyrrolidine in the place of dimethylamine in BOP[3]. PyBroP was developed as an alternative to the BOP reagent to avoid the release of toxic HMPA during the activation step[4. 5]. This capability makes PyBroP an essential tool in medicinal chemistry for synthesizing complex bioactive peptides intended for therapeutic drug development.
References:
[1] Coste J, Frerot E, Jouin P. Coupling N-methylated amino acids using PyBroP and PyCloP halogenophosphonium salts: mechanism and fields of application[J]. The Journal of Organic Chemistry, 1994, 59(9): 2437-2446.
[2] Humphrey J M, Chamberlin A R. Chemical synthesis of natural product peptides: coupling methods for the incorporation of noncoded amino acids into peptides[J]. Chemical Reviews, 1997, 97(6): 2243-2266.
[3] El-Faham A, Albericio F. Peptide coupling reagents, more than a letter soup[J]. Chemical reviews, 2011, 111(11): 6557-6602.
[4] Han S Y, Kim Y A. Recent development of peptide coupling reagents in organic synthesis[J]. Tetrahedron, 2004, 60(11): 2447-2467.
[5] Valeur E, Bradley M. Amide bond formation: beyond the myth of coupling reagents[J]. Chemical Society Reviews, 2009, 38(2): 606-631.