Modular Synthesis of Multisubstituted Furans through Palladium-Catalyzed Three-Component Condensation of Alkynylbenziodoxoles, Carboxylic Acids, and Imines

• Published in: Angewandte Chemie International Edition Vol. 54; no. 38; pp. 11107 - 11111
• Main Authors: Wu, Junliang, Yoshikai, Naohiko
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 14.09.2015; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Acids; Carboxylic acids; Carboxylic Acids - chemistry; Catalysis; Chemistry; Chemistry, Multidisciplinary; Cobalt; Condensation; Condensing; Cross coupling; Furans; Furans - chemical synthesis; hypervalent iodine compounds; Imines; Imines - chemistry; Iodobenzenes; Iodobenzoates - chemistry; Modular; multicomponent reactions; palladium; Palladium - chemistry; Physical Sciences; Science & Technology; Synthesis; Synthesis (chemistry); multicomponent reactions; ANNULATION; imines; ALKYNES; SUBSTITUTED FURANS; FUNCTIONALIZATION; KETONES; HETEROCYCLES; furans; REGIOSELECTIVE SYNTHESIS; POLYSUBSTITUTED FURANS; hypervalent iodine compounds; palladium; GENERATION; CYCLIZATION
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201504687

Mild and regiocontrolled synthesis of a multisubstituted furan is achieved through Pd(OAc)2‐catalyzed room‐temperature condensation of an alkynylbenziodoxole, a carboxylic acid, and an enolizable ketimine, which contribute to C1, CO, and C2 fragments, respectively, to the furan skeleton. The reaction tolerates a broad range of functional groups in each of the reaction components, and enables highly modular and flexible synthesis of variously substituted furans. The reaction is particularly effective for the rapid generation of tri‐ and tetraarylfurans and furan‐containing oligoarylenes without relying on conventional cross‐coupling chemistry. The regiocontrolled synthesis of a multisubstituted furan through palladium‐catalyzed condensation of an alkynylbenziodoxole, a carboxylic acid, and an enolizable ketimine is reported. The three‐component reaction allows highly modular, flexible, and mild synthesis of diversely substituted furans including furan‐containing oligoarylenes.