Metal-Free Cross-Dehydrogenative C-O Coupling of Carbonyl Compounds with N-Hydroxyimides: Unexpected Selective Behavior of Highly Reactive Free Radicals at an Elevated Temperature was written by Krylov, Igor B.;Lopat’eva, Elena R.;Budnikov, Alexander S.;Nikishin, Gennady I.;Terent’ev, Alexander O.. And the article was included in Journal of Organic Chemistry in 2020.Quality Control of Methyl2-methylbutyrate This article mentions the following:
Cross-dehydrogenative C-O coupling of N-hydroxyimides with ketones, esters, and carboxylic acids was achieved employing the di-tert-Bu peroxide as a source of free radicals and a dehydrogenating agent. The proposed method is exptl. simple and demonstrates the outstanding efficiency for the challenging CH substrates, such as unactivated esters and carboxylic acids. It was shown that N-hydroxyphthalimide drastically affects the oxidative properties of t-BuOOt-Bu by intercepting the t-BuO• radicals with the formation of phthalimide-N-oxyl radicals, a species responsible for both hydrogen atom abstraction from the CH reagent and the selective formation of the C-O coupling product by selective radical cross-recombination. The practical applicability of the developed method was exemplified by the single-stage synthesis of com. reagent (known as Baran aminating reagent precursor) from isobutyric acid and N-hydroxysuccinimide, whereas in the standard synthetic approach, four stages are necessary. In the experiment, the researchers used many compounds, for example, Methyl2-methylbutyrate (cas: 868-57-5Quality Control of Methyl2-methylbutyrate).
Methyl2-methylbutyrate (cas: 868-57-5) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Quality Control of Methyl2-methylbutyrate
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics