title: Site-selective methylation of N(beta)-nosyl hydrazides of N-nosyl protected alpha-amino acids.
abstract: The methylation reaction of N(beta)-nosyl hydrazides of N-nosyl protected alpha-amino acids by using diazomethane shows a controlled regiochemical trend and makes it possible to obtain the corresponding products methylated at specific positions depending on the amount of diazomethane used. The observed selectivity is closely connected with the different acidity of sulfonyl hydrazide, sulfonamide, and acyl hydrazine protons present in the analyzed substrates. The reactivity order of these three diverse reactive sites is supported by theoretical calculations. The hydrazine derivatives considered in this work belong to a class of compounds with interesting biological activity and of great interest in organic synthesis.
authors.affiliation: Dipartimento di Scienze Farmaceutiche, Universit della Calabria, Ed. Polifunzionale, 87036, Arcavacata di Rende, Italy.
authors.forename: Rosaria
authors.initials: R
authors.lastname: De Marco
authors.forename: Antonella
authors.initials: A
authors.lastname: Leggio
authors.forename: Angelo
authors.initials: A
authors.lastname: Liguori
authors.forename: Tiziana
authors.initials: T
authors.lastname: Marino
authors.forename: Francesca
authors.initials: F
authors.lastname: Perri
authors.forename: Nino
authors.initials: N
authors.lastname: Russo
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003198:Computer Simulation; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry; D008745:Methylation; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D006834:Hydrazines