Synthesis, reactivity, and crystallography of a sterically hindered acyl triflate

Abstract

2,6-Dimesitylbenzoyl triflate (1) has been prepared from the corresponding acid chloride, and its structure and reactivity with some small molecules is described. Notably, methods for cleaving ethereal C–O bonds under mild conditions with regioselectivity, generation of alkyl triflates in situ from ethers, and introduction of m-terphenyl groups via flexible alkoxy linkers to nucleophiles of interest are described. Advantages and limitations of cyclic ether polymerizations are also detailed. Some acylammonium reaction intermediates were also prepared and characterized. An intramolecular Friedel-Crafts acylation competes with other substrates at elevated temperatures, such that haloarenes are not appreciably acylated. Six compounds were characterized by XRD owing to the crystallinity of the 2,6-dimesitylphenyl group, which was used to scrutinize the carbonyl moiety in a variety of functional groups.