Journal article

Formation of Methylmagnesium or Coordinated Ylide? Competition between Decarboxylation of Acetate and Betaine Ligands in [CH3CO2MgO2CCH2X(CH3)(2)]( ) (where X = NCH3 and S)

George N Khairallah, Ellie Jung Hwa Yoo, Richard AJ O'Hair

ORGANOMETALLICS | AMER CHEMICAL SOC | Published : 2010

Abstract

Decarboxylation of the ligands in the magnesium cations [CH 3CO2MgO2CCH2X(CH3) 2]+ (where X = NCH3, la; and S, 1b) can give rise to either an organometallic cation [CH3MgO2CCH 2X(CH3)2]+, 2, or a coordinated ylide [CH3CO2MgCH2X(CH3) 2]+, 3. Collision-induced dissociation of a precursor complex in which the acetate ligand was 13C labeled allowed the direct determination of the relative ratio of formation of 2 and 3 via a comparison of the losses of 13CO2 and CO2. For the nitrogen betaine, la, both 2a and 3a are formed, in a ratio of ca 1:3, respectively. In contrast, for the sulfur betaine, lb, the coordinated ylide, 3b, is almost exclusively formed. These striking differences are confirmed b..

View full abstract

Grants

Funding Acknowledgements

We thank the ARC for financial support and VICS for the Chemical Sciences High Performance Computing Facility and the Victorian Partnership For Advanced Computing (VPAC).