Highly selective acylation of alcohols and amines by an indium triiodide-catalysed transesterification process

Abstract

A very simple method has been developed for the acylation of alcohols and amines by ethyl acetate through an indium triiodide-catalysed transesterification process. Using this method acylation of a primary OH group in the presence of secondary and phenolic OH groups, and of a primary NH 2 in the presence of secondary NH and primary OH have been achieved with high selectivity.

Indium Metal and Its Halides in Organic Synthesis

“…It was subsequently discovered that the reduction of α-halocarbonyl compounds by indium metal proceeds very efficiently in water under sonication. [18] A wide range of structurally diverse α-iodo and α-bromo ketones and esters have been reduced according to this procedure to provide the corresponding dehalogenated carbonyl compounds. The results are reported in Table 4.…”

Manganese(III) bis(2-hydroxyanil)acetylacetonato complex as effective catalyst for acylation of alcohols, amines and phenols with acetic anhydride

“…Recently, Vedejs and co-workers reported tributylphosphine to be a similar catalyst for the acylation of alcohols [4]. In addition to the above catalysts, toluenep-sulfonicacid [5], zinc chloride [6], cobalt chloride [7], scandium trifluoromethanesulfonate [8], tantal pentachloride [9], copper(II) triflate [10], Me 3 SiOTF [11], scandium triflate [8,12], indium(III) triflate [13], bismuth(III) triflate [14], lithium perchlorate [15], yttria-zirconica based Lewis acid [16], indium triiodide [17], montmorillonite K-10 and KSF [18], magnesium bromide [19], bismuth(III) salts [20], ferric perchlorate adsorbed on silica-gel [21], tin(IV) tyetraphenylporphyrin perchlorate [22] [24] are also known to catalyse the acylation of alcohols and amines with acid anhydrides. Nevertheless, there is still a great demand for acid catalysts to generate esters under mild conditions and environmentally friendly processes.…”

CuBr2 Catalyzed One-Pot Transprotection of TBDMS Ethers to Acetates/benzoates: Chemoselective Acetylation of Aliphatic in the Presence of Aromatic TBDMS Ethers

“…In the first place, we examined the reaction of 1-hexadecanol TBDMS ether [9] (1) and Ac 2 O (2.0 equiv) with CuBr 2 (30 mol%) in acetonitrile at ambient temperature. To our satisfaction, hexadecyl acetate [10] (2) was formed in 62% yield along with 1-hexadecanol [9] (3) (19%) under stirring for 16 h ( Table 1, entry 1). More interestingly, use of AcCl (2.0 equiv) in place of Ac 2 O in the above reaction yielded 2 as the sole product in excellent yield (84%) in one hour without any trace of 1-hexadecanol ( In order to extend the scope of this reaction, a variety of alcoholic and phenolic TBDMS ethers such as 5 [9], 7 [9], 10 [9], 12 [9], 14, 17 and 19 [11] were prepared and used for the transprotection to their corresponding acetates.…”