title: Conclusive evidence for a retention-retention pathway for the molybdenum-catalyzed asymmetric alkylation.
abstract: Enantiomerically enriched, deuterated branched carbonates (Z)-(S)-PhCH(O2COMe)-CH=CHD (1a), (Z)-(R)-PhCH(O2COMe)CH=CHD (2a), and linear carbonate (E)-(S)-PhCH=CHCHD(O2COMe) (12) were employed as probes in the Mo-catalyzed asymmetric allylic alkylation with sodium dimethyl malonate, catalyzed by ligand complex 10 derived from the mixed benzamide/picolinamide of (S,S)-trans-diaminocyclohexane and (norbornadiene)Mo(CO)4. X-ray crystallography, along with solution NMR structural analysis of the pi-allyl intermediate and competition experiments, conclusively established the reaction proceeded via a retention-retention pathway. This mechanism contrasts with that defined for Pd-catalyzed allylic alkylations, which proceed via an inversion-inversion pathway.
authors.affiliation: School of Chemistry, University of Bristol, Bristol BS8 ITS, UK. guy.lloyd-jones@bristol.ac.uk
authors.forename: Guy C
authors.initials: GC
authors.lastname: Lloyd-Jones
authors.forename: Shane W
authors.initials: SW
authors.lastname: Krska
authors.forename: David L
authors.initials: DL
authors.lastname: Hughes
authors.forename: Laure
authors.initials: L
authors.lastname: Gouriou
authors.forename: Veronique D
authors.initials: VD
authors.lastname: Bonnet
authors.forename: Kevin
authors.initials: K
authors.lastname: Jack
authors.forename: Yongkui
authors.initials: Y
authors.lastname: Sun
authors.forename: Robert A
authors.initials: RA
authors.lastname: Reamer