title: Evaluation of phosphinoamidoester-derived Pd catalysts in the asymmetric allylic alkylation reaction: theoretical studies and mechanistic insights.
abstract: Two simple hemilabile P,O-coordinating phosphinoamidoester ligands 6a and 6b were synthesized and studied in the Pd(0)-catalyzed asymmetric allylic alkylation of rac-1,3-diphenylpropenyl acetate affording a highest ee of 83% ee with 6a. To gain an insight into the actual mechanism of this catalytic reactions, which had previously been investigated with a first generation family of P,O-coordinating phosphinoamido-alcohol ligands-4a and 4b-a semiempirical computational study was carried out with the Pd-allyl complexes formed from both 4a and 6a including Hitchcock's phosphinoamido-alcohol ligand 5 (R(1)= H, R(2)= Ph). The results of this study substantiate a working model that has previously been proposed for this reaction using hemilabile P,O-coordinating phosphinoamido-type ligands.
authors.affiliation: Departamento de Química and Centro de Química de Évora, Universidade de Évora, Rua Romão Romalho 59, 7000 Évora, Portugal.
authors.forename: Vanda R D
authors.initials: VR
authors.lastname: Marinho
authors.forename: J P Prates
authors.initials: JP
authors.lastname: Ramalho
authors.forename: Ana Isabel
authors.initials: AI
authors.lastname: Rodrigues
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Burke