Visible-light-initiated external photocatalyst-free synthesis of α,α-difluoro-β-ketoamides from 4-aminocoumarins

Abstract

A concise and efficient ring-opening difluorination strategy was developed for the synthesis of highly functionalized hydroxy-containing α,α-difluoro-β-ketoamides from the one-pot multicomponent reaction of 4-aminocoumarins, NFSI, and water in dimethyl carbonate...

Visible photons as ideal reagents for the activation of coloured organic compounds

“…Finally, the water hydrolysis of 62.9 produced the primary amine 62.11 that promoted the aminolysis of the lactone moiety on the resulting ketone 62.10, thus leading to the desired a,a-difluoro-b-ketoamides. 212…”

“…With this protocol, compounds 62.3a–c were successfully synthesized under mild conditions in up to 91% yield. 212…”

“…With this protocol, compounds 62.3a-c were successfully synthesized under mild conditions in up to 91% yield. 212 The first photochemical event was the release of a fluorine atom through the photocleavage of the N-F bond in NFSI 62.1, which smoothly added to 62.2a-c. The N-centered radical 62.4 underwent a HAT reaction with 62.5, yielding 62.7.…”