Inhibition of Kornblum Reaction with Lithium Salts in S2 Reactions of Sulfonates and a Nucleophile Containing a Pyridine -Oxide Moiety: Convergent and Selective Synthesis of an MRGPRX2 Antagonist.

A critical step in the development of a convergent synthesis of an MRGPRX2 antagonist () was the S2 reaction with a highly functionalized lactamide electrophile and a unique difluoropiperidine nucleophile containing a pyridine -oxide moiety. Initial reactions with sulfonate leaving groups exhibited superb stereoselectivity, but yields were very low due to side reactions originated from competitive Kornblum reactions of the pyridine -oxide and the sulfonates. Markedly improved reaction profiles were achieved by including stoichiometric lithium triflate.

Selective Aerobic Oxidation of Alcohols over Atomically-Dispersed Non-Precious Metal Catalysts.

Catalytic oxidation of alcohols often requires the presence of expensive transition metals. Herein, it is shown that earth-abundant Fe atoms dispersed throughout a nitrogen-containing carbon matrix catalyze the oxidation of benzyl alcohol and 5-hydroxymethylfurfural by O in the aqueous phase. The activity of the catalyst can be regenerated by a mild treatment in H .