1337967-75-5Relevant academic research and scientific papers
The role of the counterion and of silicon chelation in the selective mono(trifluoromethylation) of tartaric acid derived 1,4-diketones
Harakat, Dominique,Massicot, Fabien,Nonnenmacher, Jean,Grellepois, Fabienne,Portella, Charles
supporting information; experimental part, p. 10636 - 10642 (2011/11/06)
The addition of trifluoromethyl(trimethyl)silane (TFMTMS) to tartaric acid derived aromatic 1,4-diketones was reported to be highly stereoselective but also chemoselective towards a monoaddition product. This chemoselectivity remained unexplained. Complementary experiments and monitoring of the reaction by electrospray ionization mass spectrometry (ESI-MS) show that: i) the countercation (tetrabutylammonium (TBA+) or Cs+) associated to the initiator and the charged intermediates in the chain reaction plays a crucial role and ii) in the case of a tetrabutylammonium salt initiator, the second addition on the preformed monoadduct does occur but the resulting bis(trifluoromethyl)carbinolate is unable to evolve through the chain-transfer process and it exhibits an intramolecular Si-O interaction.
