title: Determination of the Enantiomerization Barrier of the Residual Enantiomers of C3 -Symmetric Tris[3-(1-Methyl-2-Alkyl)Indolyl]Phosphane Oxides: Case Study of a Multitasking HPLC Investigation Based on an Immobilized Polysaccharide Stationary Phase.
abstract: The residual enantiomers of three tris-(3-indolyl)-phosphane oxides bearing different alkyl groups (methyl, ethyl or i-propyl) in position 2 of the indole rings constituting the blades were separated on the immobilized type Chiralpak IC column in polar organic and reversed-phase modes. The good enantioselectivity and versatility of the IC CSP allowed easy isolation of the enantiomerically highly enriched samples suitable for configurational stability studies. The enantiomerization barriers of residual phosphane oxides were evaluated both by off-column techniques (CD signal and enantiomeric purity decay kinetics) and by dynamic enantioselective high-performance liquid chromatography (HPLC).
authors.affiliation: Istituto di Scienze e Tecnologie Molecolari, Consiglio Nazionale delle Ricerche, Milano, Italy.
authors.forename: Simona
authors.identifier: http://orcid.org/0000-0003-2263-0954
authors.initials: S
authors.lastname: Rizzo
authors.affiliation: Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Roma, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Menta
authors.affiliation: Dipartimento di Scienza ed Alta Tecnologia, Università degli Studi dell'Insubria, Como, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Benincori
authors.affiliation: Dipartimento di Chimica del Farmaco, Istituto Superiore di Sanità, Roma, Italy.
authors.forename: Rosella
authors.initials: R
authors.lastname: Ferretti
authors.affiliation: Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Università di Roma, Roma, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Pierini
authors.affiliation: Dipartimento di Chimica del Farmaco, Istituto Superiore di Sanità, Roma, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Cirilli
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano, Milano, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Sannicolò
keywords: Chiralpak IC; chiral phosphane oxides; circular dichroism; dynamic enantioselective HPLC; enantiomerization barrier; enantioselective HPLC; propellers, residual enantiomers