Research Seminar: Exploring and Exploiting New Reactivity of Alkyl-Tricarbastannatranes in Lewis Acid and Transition Metal Catalysis

Presented by: ​Eric Fillion, Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada

My research group has recently characterized the structure and determined the Lewis acidity of tricarbastannatranes [N(CH₂CH₂CH₂)₃Sn]⁺(X)^- (X = BF₄, SbF₆, B[(3,5-(CF₃)₂(C₆H₃)]₄). The tin complexes were prepared by the reaction of N(CH₂CH₂CH₂)₃SnCl with AgBF₄, AgSbF₆, and AgB[(3,5-(CF₃)₂(C₆H₃)]₄, respectively (Figure 1). In parallel, the reactivity of hypervalent alkyl-tricarbastannatranes with B(C₆F₅)₃ was investigated; the axial alkyl ligand is transferred from the tin center to the boron center, with the exception of isopropyl, for which hydride transfer was observed. Furthermore, it has been demonstrated that [N(CH₂CH₂CH₂)₃Sn]⁺[MeB(C₆F₅)₃]^- promotes the conjugate addition of alkyl-tricarbastannatranes (alkyl and hydride) to electron-deficient alkenes such as benzylidene Meldrum’s acids; detailed mechanistic studies will be presented.^[1,2,3] In addition, it has been shown that pentacoordinated alkyl-tricarbastannatranes efficiently transmetalate with cationic Pd(II) centers,^[4] and cationic Rh(I) catalysts (Figure 1).

Figure. 1 Alkyl-tricarbastannatranes Reactivity

References:

[1] A. Kavoosi; E. Fillion Angew. Chem. Int. Ed., 2015, 54, 5488-5492.

[2] E. Fillion, A. Kavoosi, K. Nguyen, C. Ieritano Chem. Commun. 2016, 52, 12813-12816.

[3] P. Simidzija, M. J. Lecours, R. A. Marta, V. Steinmetz, T. B. McMahon, E. Fillion, W. S. Hopkins Inorg. Chem. 2016, 55, 9579-9585.

[4] E. Fillion; N. J. Taylor J. Am. Chem. Soc., 2003, 125, 12700-12701.