The silver(I)‐mediated decarboxylative fluorination of paraconic acids using Selectfluor® as a fluorine source is reported. Readily available paraconic acids undergo decarboxylative fluorination with Selectfluor® mediated by AgNO3 to give the corresponding β‐fluorinated γ‐butyrolactones in moderate to good yields. This approach serves as a direct and site‐selective strategy for the introduction of a fluorine atom at the β position of γ‐butyrolactone cores. The fluorinated products are synthetically useful scaffolds for organic synthesis.
Monofluorinated cyclic nitrogen‐containing compounds are synthetically useful scaffolds in organic synthesis and medicinal applications. In this report, AgNO3 mediated decarboxylative fluorination of β‐carboxyl‐γ‐butyrolactams using Selectfluor® as a fluorine source was described to achieve a site‐specific synthesis of β‐fluorinated γ‐butyrolactams.
A convenient synthetic approach to α,β-unsaturated γ-butyrolactones and α,β-unsaturated γ-butyrolactams is developed. The reaction proceeds via decarboxylative iodination of paraconic acids and β-carboxyl-γ-butyrolactams, employing 1,3-diiodo-5,5-dimethylhydantoin (DIH) under irradiation, followed by dehydroiodination of β-iodo-γ-butyrolactones and γ-butyrolactams providing good yields of α,β-unsaturated γ-butyrolactones and γ-butyrolactams, which are synthetically useful building blocks in organic synthesis.
Decarboxylative transformations of paraconic acids, a class of γ-butyrolactones containing a carboxylic acid group at the β position as their characteristic functionality, using a combination of AgNO3/K2S2O8 was investigated. The dual function of AgNO3 as an initiator for decarboxylation process and a nitrogen dioxide radical source that reacts with aliphatic carboxylic substrates of this study was reported for the first time. Starting from paraconic acids, β-nitro- and β-hydroxy γ-butyrolactones were obtained in good combined yields (41-85% yields) with moderate selectivity in one-pot operation. The reactions completed within acceptable reaction time (2 h) under mild reaction conditions that γ-butyrolactone core could be tolerated. The present study represents the direct and site-specific entry to β-nitro- and β-hydroxy γ-butyrolactones which are important precursors in organic transformations.
Silver-Mediated Decarboxylative Fluorination of Paraconic Acids: A Direct Entry to -Fluorinated -Butyrolactones. -(PHAE-NOK, S.; SOORUKRAM*, D.; KUHAKARN, C.; REUTRAKUL, V.; POHMAKOTR, M.; Eur. J. Org. Chem. 2015, 13, 2879-2888, http://dx.
As frequently encountered byproducts of isocyanate chemistry,
hydrogen
sulfide and related sulfur containing compounds should be treated
in a safe way to lower their adverse health and environmental effects,
especially in large scale syntheses. As a proof of concept, we report
herein an example of in situ recycling of sulfur byproduct to reductant
in the synthesis of bioactive 2-aminobenzoxazoles 3.
Using an Fe/S catalytic system, this heterocyclic scaffold could be
obtained from o-nitrophenols 1 with
isothiocyates 2 via direct redox condensation consisting
of reduction of the nitro group of 1 by the sulfur moiety
of 2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.