title: The 9-phenyl-9-fluorenyl group for nitrogen protection in enantiospecific synthesis.
abstract: One of the biggest challenges in asymmetric synthesis is to prevent racemization of enantiopure starting materials. However, at least some of the enantiopurity is lost in most of the existing reactions used in synthetic organic chemistry. This translates into unnecessary material losses. Naturally enantiopure proteinogenic amino acids that can be transformed into many useful intermediates in drug syntheses, for example, are especially vulnerable to this. The phenylfluoren-9-yl (Pf) group, a relatively rarely used protecting group, has proven to be able to prevent racemization in α-amino compounds. This review article showcases the use of Pf-protected amino acid derivatives in enantiospecific synthesis.
authors.affiliation: Department of Chemistry, Aalto University, School of Science and Technology, Aalto, Finland.
authors.forename: Essi J
authors.initials: EJ
authors.lastname: Karppanen
authors.forename: Ari M P
authors.initials: AM
authors.lastname: Koskinen
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry*; D055601:Organic Chemistry Phenomena; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D009584:Nitrogen