Acyloxyphosphonium salts as acylating agents. Synthesis of peptides

Synthesis of 2-(4,6-Dimethoxy-1,3,5-triazin-2-yloxyimino) Derivatives: Application in Solution Peptide Synthesis

“…During the last decade, iminium/uronium and phosphonium salts of 1-hydroxybenzotriazole and 1-hydroxy-7-azabenzotriazole, 5 and 6 (Figure 2)have shown the supremacy of these kind of derivatives over carbodiimides in the presence of an additive [5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33]. …”

Methods for the Peptide Synthesis and Analysis

“…Kenner and coworkers [95] were the first to describe the use of acylphosphonium salts as coupling reagents. After HOBt (41) was discovered as a racemization suppressant, a new coupling reagent, known as BOP (benzotriazol-1-yloxytris(dimethylamino)-phosphonium hexafluorophosphate) (47), was introduced in 1975 [95,96].…”

“…After HOBt (41) was discovered as a racemization suppressant, a new coupling reagent, known as BOP (benzotriazol-1-yloxytris(dimethylamino)-phosphonium hexafluorophosphate) (47), was introduced in 1975 [95,96]. Later, chlorotri(pyrrolidino)phosphonium hexafluorophosphate (PyCloP) (48), bromotri (pyrrolidino)phosphonium hexafluorophosphate (PyBroP) (49), and benzotriazol-1-yloxytri(pyrrolidino)-phosphonium hexafluorophosphate (PyBOP) (50) (Figure 2.8) were introduced.…”

“…Later, chlorotri(pyrrolidino)phosphonium hexafluorophosphate (PyCloP) (48), bromotri (pyrrolidino)phosphonium hexafluorophosphate (PyBroP) (49), and benzotriazol-1-yloxytri(pyrrolidino)-phosphonium hexafluorophosphate (PyBOP) (50) (Figure 2.8) were introduced. In these compounds, the dimethylamine moiety is replaced by pyrrolidine (Figure 2.8) [95,97,98]. Pyrrolidine reagents prevent the generation of poisonous hexamethylphosphoramide (HMPA, 51) by-product [99].…”

Peptide‐Coupling Reagents

“…Kenner et al [38] were the first to describe the use of acylphosphonium salts as coupling reagents. These species were widely adopted only after the extensive studies of Castro 40].…”