The Use Of Trifluoroacetic Anhydride And Related Compounds In Organic Syntheses

Tunable Oleo-Furan Surfactants by Acylation of Renewable Furans

“…As depicted in Figure 2, long (>C10) alkyl chains are obtained from hydrolysis of triglycerides to fatty acids such as lauric acid (C12), myristic acid (C14), or stearic acid (C18) and can be converted to anhydrides by numerous existing methods including dehydration in the presence of water sorbents or other short-chain recyclable anhydrides. 22,23 Here, we demonstrate the coupling of these long alkyl chain anhydrides with furans by Friedel–Crafts acylation with heterogeneous catalysts. As shown in Figure 2B, the reaction of lauric anhydride with furan on either Lewis acid zeolites (such as Sn-BEA, Sn-MWW, or Sn-SPP) or Brønsted acid zeolites (such as Al-BEA or Al-SPP) exhibited significant activity for acylation (see Supporting Information for details).…”

A ‘cold synthesis’ of heroin and implications in heroin signature analysis

“…There is literature precedent for the use of trifluoroacetic anhydride as an ester promoter, with two methods commonly described, differing only in the order of reagent addition [41,42]. Dissolution of morphine in TFAA followed by the addition of acetic acid gives rise to very low yields of DAM, but significant quantities trifluoroacetyl esters; conversely dissolution of acetic acid in TFAA forming the mixed anhydride followed by addition of morphine proved to be an extremely clean, efficient and elegant route for the production of high quality DAM.…”

“…Furthermore all TFAA samples contained traces of morphine and codeine, whereas morphine was only detected in only two and codeine in none of the AA samples (data not shown). It is noteworthy to mention that trifluoroacetyl esters are notoriously unstable, readily hydrolysed under conditions required for analysis (see Section 6), meaning that their detection in clandestine laboratory samples is difficult [41,42], this is the most probable explanation for the increased concentrations of 3-MAM, 6-MAM, morphine and codeine detected. Current HSP methodologies have evolved to deal with DAM synthesised via morphine acetylation by AA at elevated temperature, we thus felt it crucial that this new methodology be examined and key constituents analysed in an attempt to gather data as to how TFAA might impinge on existing HSP protocols.…”

“…The formation of 29 involves the acetylation of the secondary amine group in N-norlaudanosine [22], which is a function of nucleophile strength, with increased prevalence for attack at the trifluoroacetyl carbonyl, of the mixed anhydride formed in situ, increasing with the reactivity of the nucleophile [41]. Hence the TFAA procedure favours trifluoroacetylation, decreasing the amount of 29 observed.…”

Gram-Scale Production and Applications of Optically Pure13C-Labelled (+)-Catechin and (−)-Epicatechin

“…Tri-O-benzylphloroacetophenone (5), labelled at the carbonyl group, was synthesized by acylating 4 (117 g) with 1-[ 13 C]acetic acid (99% 13 C enrichment) in the presence of trifluoroacetic anhydride (Scheme 2), [3,6,7] giving 75 g of pure 5 after silica gel column chromatography (58% from 4). Selective deprotection of 5 was achieved by the action of TiCl 4 , yielding 47 g of pure 6 (80%) after purification from the C-benzylated by-product 7 (7%).…”