New research by Professor Guy Lloyd-Jones and co-workers has recently been published that provides a detailed understanding of a reaction mechanism for producing fluorochemicals.
The paper, titled "Difluorocarbene Generation from TMSCF3: Kinetics and Mechanism of NaI-Mediated and Si-Induced Anionic Chain Reactions" and published in the Journal of the American Chemical Society, reports a detailed kinetic and mechanistic analysis of the generation of a short-lived highly reactive molecule (difluorocarbene) from the Ruppert-Prakash reagent.
The Ruppert-Prakash reagent has become very cheap and is entering into reactions used in industrial production of specialist fluorochemicals. However, large excesses of the Ruppert-Prakash reagent are required, leading to major concerns regarding waste, the toxicity of side products, and the hazardous and unpredictable nature of scaling up these spontaneously self-heating reactions. The process has been studied by many groups from the synthetic viewpoint, but all of the new results only added controversies to understanding its mechanism. This comprehensive new study sheds the light on nearly all these controversies. The definitive understanding presented in the paper will be invaluable for process development in industry, and for teaching around this increasingly important reagent.
Referees considered the paper "a tour de force exploring conditions, kinetics, additives KIE effects, and DFT" and "a brilliant work revealing almost all aspects of the difluorocarbene generation from TMSCF3" and noted that "the key mechanism proposed by authors - an autocatalytic anionic chain reaction - is quite uncommon, it will certainly take place in future textbooks on advanced organic chemistry"