64985-86-0Relevant articles and documents
Size-Driven Inversion of Selectivity in Esterification Reactions: Secondary Beat Primary Alcohols
Mayr, Stefanie,Marin-Luna, Marta,Zipse, Hendrik
, p. 3456 - 3489 (2021/03/01)
Relative rates for the Lewis base-mediated acylation of secondary and primary alcohols carrying large aromatic side chains with anhydrides differing in size and electronic structure have been measured. While primary alcohols react faster than secondary ones in transformations with monosubstituted benzoic anhydride derivatives, relative reactivities are inverted in reactions with sterically biased 1-naphthyl anhydrides. Further analysis of reaction rates shows that increasing substrate size leads to an actual acceleration of the acylation process, the effect being larger for secondary as compared to primary alcohols. Computational results indicate that acylation rates are guided by noncovalent interactions (NCIs) between the catalyst ring system and the DED substituents in the alcohol and anhydride reactants. Thereby stronger NCIs are formed for secondary alcohols than for primary alcohols.
TBHP/ n -Bu 4 PBr-Promoted Oxidative Cross-Dehydrogenative Coupling of Aryl Methanols: A Facile Synthesis of Symmetrical Carboxylic Anhydride Derivatives
Adib, Mehdi,Pashazadeh, Rahim
supporting information, p. 136 - 140 (2017/12/27)
A transition-metal-free oxidative cross-dehydrogenative coupling reaction has been developed for the preparation of symmetrical carboxylic anhydrides through self-coupling dual C-O bond formations of aryl methanols. In the presence of a catalytic amount of tetrabutylphosphonium bromide (TBPB) as transfer agent and aqueous tert -butyl hydroperoxide (TBHP) as oxidant and reactant, methylene groups of aryl methanols were efficiently oxidized to C=O and coupled with the peroxide oxygen from TBHP to form a diverse array of symmetrical carboxylic anhydride derivatives.
Metal-free cross-dehydrogenative coupling of aryl aldehydes to give symmetrical carboxylic anhydrides promoted by the TBHP/nBu4PBr system
Adib, Mehdi,Pashazadeh, Rahim,Rajai-Daryasarei, Saideh,Mirzaei, Peiman,Jamal Addin Gohari, Seyed
supporting information, p. 3071 - 3074 (2016/07/06)
A novel, efficient, and metal-free dual C–O bond formation reaction for the synthesis of carboxylic anhydrides from aryl aldehydes via cross-dehydrogenative coupling is described. Heating a mixture of aromatic aldehydes and an aqueous solution of tert-butyl hydroperoxide as oxidant in the presence of catalytic nBu4PBr in chlorobenzene at 80?°C for 3?h afforded the corresponding carboxylic anhydrides in good to excellent yields.
