Palladium‐Catalyzed Decarboxylative Heck‐Type Coupling of Activated Aliphatic Carboxylic Acids Enabled by Visible Light. Issue 18 (9th March 2018)

• Record Type: Journal Article
• Authors: Koy, Maximilian; Sandfort, Frederik; Tlahuext‐Aca, Adrian; Quach, Linda; Daniliuc, Constantin G.; Glorius, Frank
• Is Part Of: Chemistry. Volume 24:Issue 18(2018)
• Page Start: 4552
• Page End: 4555
• Publication Date: 2018-03-09
• Subjects: carboxylic acids -- decarboxylation -- Heck-type coupling -- palladium -- redox-active esters; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201800813
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The palladium‐catalyzed coupling reaction of N ‐hydroxyphthalimide esters and styrenes to deliver exclusively ( E )‐substituted olefins under irradiation with visible light is reported. This method tolerates N ‐hydroxyphthalimide esters derived from primary, secondary, tertiary as well as benzylic carboxylic acids. Notably, Pd(PPh3 )4 is employed as an inexpensive palladium source and no addition of base or classical photocatalyst is required. Mechanistic studies suggest a light‐mediated single‐electron reduction of the activated acid by a photoexcited palladium(0) species to access alkyl radicals through decarboxylation. Abstract : A palladium‐catalyzed coupling reaction of N ‐hydroxyphthalimide esters and styrenes to deliver ( E )‐substituted olefins in perfect selectivity under irradiation with visible light is reported. This method tolerates N ‐hydroxyphthalimide esters derived from primary, secondary, tertiary, and benzylic carboxylic acids, also including complex naturally occurring carboxylic acids. Pd(PPh3 )4 is employed as an inexpensive palladium source and no addition of base or classical photocatalyst is required. Mechanistic studies suggest a light‐mediated single‐electron reduction of the activated acid by a photoexcited palladium(0) species.