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The 3‐(3‐Pyridyl)allyloxycarbonyl (Paloc) Moiety—a Stable, Amino‐Protecting Group for Peptide Syntheses in Organic Media and in Water That Is Cleavable under Neutral Conditions
Author(s) -
von dem Bruch Karsten,
Kunz Horst
Publication year - 1990
Publication title -
angewandte chemie international edition in english
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 0570-0833
DOI - 10.1002/anie.199014571
Subject(s) - moiety , dipeptide , protecting group , nucleophile , chemistry , cleavage (geology) , amino acid , peptide , stereochemistry , combinatorial chemistry , functional group , group (periodic table) , catalysis , organic chemistry , biochemistry , biology , paleontology , alkyl , polymer , fracture (geology)
The Paloc‐protected amino function in dipeptide esters such as 1 is stable even towards strong acids. This enables selective, quantitative cleavage of the t Bu group with HCl in Et 2 O/CH 2 Cl 2 . Conversely, the directed removal of the Paloc‐protecting group is achieved by palladium(0)‐catalyzed allyl transfer to weakly basic nucleophiles such as N ‐methylaniline. In this reaction many protecting groups remain intact, i.e. sensitive structures are not destroyed.