title: Highly enantiomerically enriched chlorophosphine boranes: synthesis and applications as P-chirogenic electrophilic blocks.
abstract: The stereoselective synthesis of P-chirogenic chlorophosphine boranes 4 was investigated by HCl acidolysis of the corresponding aminophosphine boranes 10. The reaction afforded the P-N bond cleavage with inversion of the configuration at the phosphorus center, leading to the chlorophosphine boranes 4 with high to excellent enantiomeric purities (80-99% ee), except in the case of the chloro-1-naphthylphenylphosphine borane 4d. Reaction conditions and workup significantly influence the enantiomeric purity of the product, with the exception of the o-anisyl- and o-tolylchlorophenylphosphine boranes, 4b and 4c, which were found to be particularly stable even after purification by chromatography on silica gel. Reaction of the chlorophosphine boranes 4 with various nucleophiles, such as carbanions, phenolates, thiophenolates, or amides, afforded the corresponding organophosphorus borane complexes via P-C, P-O, P-S, and P-N bond formation, respectively, in 34-93% yield and with up to 99% ee. This work demonstrates the importance of chlorophosphine boranes 4 as new and powerful electrophilic building blocks for the highly stereoselective synthesis of P-chirogenic organophosphorus compounds.
authors.affiliation: Laboratoire de Synthèse et d'Electrosynthèse Organométalliques, UMR 5632, Université de Bourgogne, 6 Bd Gabriel, BP 138, 21100 Dijon, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Bauduin
authors.forename: Dominique
authors.initials: D
authors.lastname: Moulin
authors.forename: El Bachir
authors.initials: el B
authors.lastname: Kaloun
authors.forename: Christophe
authors.initials: C
authors.lastname: Darcel
authors.forename: Sylvain
authors.initials: S
authors.lastname: Jugé