A Phosphonium Ylide as an Ionic Nucleophilic Catalyst for Primary Hydroxyl Group Selective Acylation of Diols

Carbonyl-stabilized
phosphonium ylides exhibit great utility in
modern organic synthesis, and they are known as an ambident nucleophile
at the carbonyl oxygen atom and at the α-carbon atom. However,
they have found limited use as catalysts. We focused on the inherent
nucleophilicity of the oxygen atom to develop an ionic nucleophilic
catalysis, and the phosphonium ylide-catalyzed primary alcohol selective
acylation of mixed diols with acid anhydrides has been demonstrated.
Mechanistic studies revealed the behavior of a catalyst, which would
contribute to the field of ylide chemistry.