File(s) under permanent embargo
Gas-phase and computational study of identical nickel- and palladium-mediated organic transformations where mechanisms proceeding via MII or MIV oxidation states are determined by ancillary ligands
journal contribution
posted on 2023-05-18, 14:51 authored by Vikse, KL, Khairallah, GN, Alireza AriafardAlireza Ariafard, Allan CantyAllan Canty, O'Hair, RAJGas-phase studies utilizing ion–molecule reactions, supported by computational chemistry, demonstrate that the reaction of the enolate complexes [(CH2CO2—C,O)M(CH3)]− (M = Ni (5a), Pd (5b)) with allyl acetate proceed via oxidative addition to give MIV species [(CH2CO2—C,O)M(CH3)(η1-CH2—CH═CH2)(O2CCH3—O,O′)]− (6) that reductively eliminate 1-butene, to form [(CH2CO2—C,O)M(O2CCH3—O,O′)]− (4). The mechanism contrasts with the MII-mediated pathway for the analogous reaction of [(phen)M(CH3)]+ (1a,b) (phen = 1,10-phenanthroline). The different pathways demonstrate the marked effect of electron-rich metal centers in enabling higher oxidation state pathways. Due to the presence of two alkyl groups, the metal-occupied d orbitals (particularly dz2) in 5 are considerably destabilized, resulting in more facile oxidative addition; the electron transfer from dz2 to the C═C π* orbital is the key interaction leading to oxidative addition of allyl acetate to MII. Upon collision-induced dissociation, 4 undergoes decarboxylation to form 5. These results provide support for the current exploration of roles for NiIV and PdIV in organic synthesis.
History
Publication title
Journal of the American Chemical SocietyVolume
137Issue
42Pagination
13588-13593ISSN
0002-7863Department/School
School of Natural SciencesPublisher
Amer Chemical SocPlace of publication
1155 16Th St, Nw, Washington, USA, Dc, 20036Rights statement
Copyright 2015 American Chemical SocietyRepository Status
- Restricted