5062-30-6Relevant articles and documents
Hypervalent Iodine Mediated C-C Double Bond Activation: A Cascade Access to α-Keto Diacetates from Readily Available Cinnamic Acids
Liu, Le,Zhang-Negrerie, Daisy,Du, Yunfei,Zhao, Kang
, p. 2924 - 2930 (2015/09/28)
The reaction of cinnamic acids with (diacetoxyiodo)benzene in 1,2-dichloroethane in the presence of sulfuric acid provides an easy and direct access to the α-keto diacetate framework. This hypervalent iodine mediated oxidative reaction involves a tandem sequence of aryl migration, insertion of an oxygen atom, decarboxylation and diacetoxylation. A reaction mechanism is proposed and discussed in light of control experiments.
Silver acetate mediated acetoxylations of alkyl halides
Nolla-Saltiel, Roberto,Carrillo-Arcos, Ulises Alonso,Porcel, Susana
supporting information, p. 165 - 169 (2014/03/21)
Silver acetate promotes the acetoxylation of alkyl halides under neutral reaction conditions. The reaction is applicable to primary and activated secondary alkyl halides, and 2,2-dibromoacetophenones for preparing the corresponding acetates in good yields. The presence of ester, amide, nitrile, hydroxy, and OTBDMS functions on the substrate is tolerated.
Reinvestigation of the mechanism of gem-diacylation: Chemoselective conversion of aldehydes to various gem-diacylates and their cleavage under acidic and basic conditions
Kavala, Veerababurao,Patel, Bhisma K.
, p. 441 - 451 (2007/10/03)
The mechanism of gem-diacylate formation has been studied extensively using tetrabutylammonium tribromide (TBATB) as the catalyst. The reaction proceeds by a nucleophilic attack of an anhydride on an aldehydic carbonyl group, nucleophilic attack of the hemiacylate intermediate on a second molecule of the anhydride, followed by an intermolecular attack of a second acetate group to regenerate the anhydride. gem-Diacylates of various aliphatic and aromatic aldehydes were obtained directly from the reaction of a variety of aliphatic and aromatic acid anhydrides in the presence of a catalytic quantity of tetrabutylammonium tribromide (TBATB) under solvent-free conditions. A significant electronic effect was observed during its formation as well as deprotection to the corresponding aldehyde. Chemoselective gem-diacylation of the aromatic aldehyde containing an electron-donating group has been achieved in the presence of an aldehyde containing an electron-withdrawing group. Deprotection of the gem-diacylate to the parent carbonyl compound can be accomplished in methanol in presence of the same catalyst. Here again, chemoselective deprotection of the gem-diacylate of a substrate containing an electron-donating group has been achieved in the presence of a substrate containing an electron-withdrawing group. Both the acid and base stability order of the various gem-diacylates examined follow a similar order. The stability order determined from the present study is: gem-dibenzoate > gem-dipivalate > gem-diisobutyrate > gem-diacetate > gem-dipropionate. All the gem-diacylals are more stable under basic conditions than acidic condition. No correlation was found between the stability order and the pKa's of the corresponding acids; rather, the stability order is directly related to the steric crowding around the carbonyl carbon. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
