85586-67-0Relevant articles and documents
Insight into the Mechanism of the Acylation of Alcohols with Acid Anhydrides Catalyzed by Phosphoric Acid Derivatives
Hayashi, Hiroyuki,Yasukochi, Shotaro,Sakamoto, Tatsuhiro,Hatano, Manabu,Ishihara, Kazuaki
, p. 5197 - 5212 (2021/04/12)
Insight into the mechanism of a safe, simple, and inexpensive phosphoric acid (H3PO4)-catalyzed acylation of alcohols with acid anhydrides is described. The corresponding in situ-generated diacylated mixed anhydrides, unlike traditionally proposed monoacylated mixed anhydrides, are proposed as the active species. In particular, the diacylated mixed anhydrides act as efficient catalytic acyl transfer reagents rather than as Br?nsted acid catalysts simply activating acid anhydrides. Remarkably, highly efficient phosphoric acid (1-3 mol %)-catalyzed acylation of alcohols with acid anhydrides was achieved and a 23 g scale synthesis of an ester was demonstrated. Also, phosphoric acid catalyst was effective for synthetically useful esterification from carboxylic acids, alcohols, and acid anhydride. Moreover, with regard to recent developments in chiral 1,1′-bi-2-naphthol (BINOL)-derived phosphoric acid diester catalysts toward asymmetric kinetic resolution of alcohols by acylation, some phosphate diesters were examined. As a result, a 31P NMR study and a kinetics study strongly supported not only the acid-base cooperative mechanism as previously proposed by other researchers but also the mixed anhydride mechanism as presently proposed by us.
Engineering reactions in crystalline solids: Radical pairs in crystals of dialkyl 1,3-acetonedicarboxylates
Yang, Zhe,Garcia-Garibay, Miguel A.
, p. 1963 - 1965 (2007/10/03)
(Equation presented) Crystalline dialkyl 1,3-acetonedicarboxylates give dialkyl succinates in high chemical yields by combination of α-carbonyl radical pairs produced by photochemical decarbonylation. It is proposed that the solid-state reaction depends on the exothermicity of two consecutive bond cleavage processes. It is also suggested that the efficiency of radical formation in the solid state is determined by the effect of substituents on bond dissociation energies and radical-stabilization abilities.
