The use of the 2-(diphenylphosphino) ethyl group for carboxyl-protection of amino acids or peptides is described. This group is easily introduced by esterification using 2- (diphenylphosphino) ethanol in the presence of dicyclohexylcarbodiimide and 4- (dimethylamino) pyridine. These Dppe esters are stable under the standard conditions for peptide synthesis. Deprotection is carried out under mild conditions by quaternisation ...
