PhI(OAc)₂/I₂‐Mediated Decarboxylative C₄‐Amination of Coumarin‐3‐Carboxylic Acids via C_sp2−H Dehydrogenative C−N Cross‐Coupling under Ambient Conditions

Abstract

An efficient and straightforward protocol for accessing a new series of functionalized 4-aminocoumarins from PIDA/I 2 -mediated decarboxylative C 4 -amination of coumarin-3-carboxylic acids via direct C sp2 À H dehydrogenative CÀ N cross-coupling with secondary amines under ambient conditions has been accomplished. The notable advantages of this protocol are the tolerance of diverse functional groups, mild reaction conditions at ambient temperature, moderate to good yields, short reaction times (in minutes), high regioselectivity, gram-scale applicability, and eco-friendliness. This is the first report of decarboxylative C sp2 À H cross-dehydrogenative CÀ N coupling of coumarin-3-carboxylic acids for synthesizing 4-aminocoumarins.

Recent Advances in the Decarboxylative Strategy of Coumarin‐3‐carboxylic Acid

“…In 2023, Brahmachari and co‐workers devised PIDA/I 2 mediated decarboxylative C‐4 amination of coumarin‐3‐carboxylic acid 1 (Scheme 29). [50] Here, a direct Csp 2 −H dehydrogenative C−N coupling reaction under optimal conditions is reported to achieve 4‐aminocoumarin 130 . The method is beneficial, as it gives good yield.…”