Reformatsky Reagent Promoted Acetylation of Primary and Secondary Aliphatic Alcohols Using Ethyl Acetate as an Acetyl Donor

Abstract

The reaction system of a Reformatsky reagent as a promoter and EtOAc as a solvent and acetyl donor was found to achieve efficient acetylation of a variety of primary and secondary aliphatic alcohols under mild conditions. The reaction can be carried out by a simple one-pot operation and does not require heating. The reaction shows a high tolerance for various functional groups and chemoselectivity, such that the phenolic hydroxyl groups do not react. Furthermore, the reaction can be used for gram-scale acetylation.

Trimethylsilyl Esters as Novel Dual-Purpose Protecting Reagents

“…AcOTMS was enhanced to 1.5, 2.0, and 3.0 equivalents, which then increased yields to 93%, 95%, and 94%, respectively. (Table 1, entries [7][8][9]. In order to obtain the best result with 2.0 equiv.…”

“…Alcohol acylation is considered to be one of the most fundamental transformation reactions. 4b 8 9 It is frequently utilized to protect hydroxyl groups, which may also allow to gain desired ester products with advantageous properties, such as easy separation and characterization. According to the literature, 10 it is known that a variety of acids have been developed as catalysts for the acylation reactions.…”

Facile Selective Acetylation of Primary Alcohols Using Ethyl Acetate in Acidic Medium

“…[16] These reactions resulted in good yields in short times (10 to 30 minutes), using DMSO as solvent and KOtBu as catalyst. Likewise, there are selective methods, using enzymes (lipase) [17] and the Reformatsky reactant, [18] which aim at the primary and secondary hydroxyl groups. Although these conditions are mild, the reaction times are substantial, taking from 16 hours to seven days when catalysed by lipase, and up to 24 hours when the Reformatsky reactant is involved.…”

Ethyl acetate as an acetyl source and solvent for acetylation of alcohols by KOH

“…The substrates containing halogen substituent also gave excellent yield of according products while no dehalogened compounds were produced (Table 3, entries 8-12). For the substrates with various electron-withdraw group (-CF 3 or -NO 2 or -CN or -C^C) also could be smoothly reacted under the standard condition, giving 87%, 83% and 84% yield of the desired products, respectively (Table 3, entries [13][14][15][16]. In which, the -CN and -C^C groups could be tolerated under the reaction condition.…”

“…The metal-based catalysts including dilithium tetra- tert -butylzincate (TBZL), 8 LiClO 4 /In(OTf) 3 , 9 Y 5 (O i Pr) 13 O, 9 ZrCl 4 -Mg(ClO 4 ) 2 , 10 CoCl 2 ·6H 2 O, 10 heterogeneous zinc/imidazole, 11 Zn 4 (OCOCF 3 ) 6 O, 12 InI 3 /I 2 , 13 Zn reagent. 14 And some transesterification of alcohols under metal-free conditions were reported, such as Cs 2 CO 3 , 15 I 2 , 16 KO t Bu, 17 K 2 CO 3 , 18 Novozyme-435, 19 TsOH, 20 ( Table 1 ).…”