title: TBAF-catalyzed deacylation of cellulose esters: reaction scope and influence of reaction parameters.
abstract: In order to expand its utility and understand how to carry it out most efficiently, the scope of the highly regioselective, tetrabutylammonium fluoride (TBAF) catalyzed deacylation of cellulose acetates has been investigated, including the influence of key process parameters: solvent, temperature, and water content. Reactions in DMSO, THF, MEK and acetone afforded similar extents of deacylation and regioselectivity. Reaction with TBAF in DMSO at 50 °C for 18 h was the most efficient process providing regioselective deacylation at O-2/3. All results were consistent with our previous mechanistic proposals. Furthermore, we demonstrate that TBAF-catalyzed deacylation is also effective and regioselective with cellulose acetate, butyrate, and hexanoate triesters, and even with a cellulose ester devoid of alpha protons, cellulose tribenzoate. These reactions displayed regioselectivity for deacylation at O-2/3 similar to that observed earlier with cellulose acetate (DS 2.4).
authors.affiliation: Department of Sustainable Biomaterials, Virginia Tech, 230 Cheatham Hall, Blacksburg, VA 24061, USA.
authors.forename: Xueyan
authors.initials: X
authors.lastname: Zheng
authors.forename: Richard D
authors.initials: RD
authors.lastname: Gandour
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Edgar
mesh_terms: D000215:Acylation; D002074:Butanones / Q000737:chemistry; D002384:Catalysis; D002482:Cellulose / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004952:Esters; D007700:Kinetics; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D002074:Butanones; D004952:Esters; D000644:Quaternary Ammonium Compounds; D012997:Solvents; D014867:Water; C005222:methylethyl ketone; D002482:Cellulose; C009405:tetrabutylammonium; D004121:Dimethyl Sulfoxide
keywords: Cellulose acetate; Cellulose ester; Deacylation; Regioselectivity; Structure–property relationships; Tetrabutylammonium fluoride