The Journal of Organic Chemistry

Coupling N-methylated amino acids using PyBroP and PyCloP halogenophosphonium salts: mechanism and fields of application

J Coste, E Frerot, P Jouin

Index: Coste, Jacques; Frerot, Eric; Jouin, Patrick Journal of Organic Chemistry, 1994 , vol. 59, # 9 p. 2437 - 2446

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Citation Number: 170

Abstract

PyBroP (1) and PyCloP (21, two halotripyrrolidinophosphonium hexafluorophosphates, are peptidecoupling reagents highly efficient for coupling N-methylated amino esters, in contrast with PyBOP (3), the hydroxybenzotriazolyl analogue. These halogenophosphonium salts 1 and 2 are convenient (one-pot reactions) stable solids soluble in conventional solvents. Use of them gave an excellent peptide yield with essentially no epimerization. Activation with ...