title: P-Stereogenic bisphosphines with a hydrazine backbone: from N-N atropoisomerism to double nitrogen inversion.
abstract: The synthesis of P-stereogenic bisphosphine ligands starting from a phosphinous acid chiral synthon and hydrazine is reported. The dialkylation of the hydrazine backbone yielded atropo- and nitrogen inversion isomers which are in slow exchange. The crystallization of one of the isomers allowed us to study the reaction kinetics of the equilibria. The new ligands were tested in the Rh catalysed asymmetric hydrogenation of various benchmark substrates attaining up to 99% ee.
authors.affiliation: Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac 10, E-08028, Spain. antoni.riera@irbbarcelona.org xavier.verdaguer@irbbarcelona.org.
authors.forename: Amparo
authors.initials: A
authors.lastname: Prades
authors.forename: Samuel
authors.initials: S
authors.lastname: Núñez-Pertíñez
authors.forename: Antoni
authors.initials: A
authors.lastname: Riera
authors.forename: Xavier
authors.initials: X
authors.lastname: Verdaguer