Frederick George Percy Remfry

Bio: Frederick George Percy Remfry is an academic researcher. The author has contributed to research in topics: Derivative (chemistry). The author has an hindex of 1, co-authored 1 publications receiving 74 citations.

Predicting Solvent Stability in Aprotic Electrolyte Li–Air Batteries: Nucleophilic Substitution by the Superoxide Anion Radical (O2•–)

Abstract: There is increasing evidence that cyclic and linear carbonates, commonly used solvents in Li ion battery electrolytes, are unstable in the presence of superoxide and thus are not suitable for use in rechargeable Li–air batteries employing aprotic electrolytes. A detailed understanding of related decomposition mechanisms provides an important basis for the selection and design of stable electrolyte materials. In this article, we use density functional theory calculations with a Poisson–Boltzmann continuum solvent model to investigate the reactivity of several classes of aprotic solvents in nucleophilic substitution reactions with superoxide. We find that nucleophilic attack by O2•– at the O-alkyl carbon is a common mechanism of decomposition of organic carbonates, sulfonates, aliphatic carboxylic esters, lactones, phosphinates, phosphonates, phosphates, and sulfones. In contrast, nucleophilic reactions of O2•– with phenol esters of carboxylic acids and O-alkyl fluorinated aliphatic lactones proceed via att...

Transnitrilation from Dimethylmalononitrile to Aryl Grignard and Lithium Reagents: A Practical Method for Aryl Nitrile Synthesis.

Abstract: An electrophilic cyanation of aryl Grignard or lithium reagents, generated in situ from the corresponding aryl bromides or iodides, by a transnitrilation with dimethylmalononitrile (DMMN) was developed. DMMN is a commercially available, bench-stable solid. The transnitrilation with DMMN avoids the use of toxic reagents and transition metals and occurs under mild reaction conditions, even for extremely sterically hindered substrates. The transnitrilation of aryllithium species generated by directed ortho-lithiation enabled a net C–H cyanation. The intermediacy of a Thorpe-type imine adduct in the reaction was supported by isolation of the corresponding ketone from the quenched reaction. Computational studies supported the energetic favorability of retro-Thorpe fragmentation of the imine adduct.