Palladium-catalyzed mono-γ-arylation of 7-methoxy-4-methylcoumarin. Issue 38 (19th September 2019)

• Record Type: Journal Article
• Authors: Sexton, Mary E.; Okazaki, Ami; Yu, Zhuowen; van Venrooy, Alexis; Schmink, Jason R.; Malachowski, William P.
• Is Part Of: Tetrahedron letters. Volume 60:Issue 38(2019)
• Publication Date: 2019-09-19
• Subjects: Enolate γ-arylation -- Palladium-catalyzed -- Coumarin -- Xantphos; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2019.151057
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Highlights: Regio- and chemoselective enolate gamma-arylation. Xantphos ligand critical to reaction success. Rapid synthesis of various C-4 benzyl coumarin derivatives. Abstract: Herein, we report the selective mono-γ-arylation of 7-methoxy-4-methylcoumarin under palladium-catalyzed conditions. The Buchwald G3 pre-catalyst in conjunction with either the Xantphos or N -Xantphos ligand proves to be highly reactive, engaging aryl iodides, bromides, chlorides, and triflates to effect the desired transformation. A wide range of functionality is tolerated, including the ability to activate heteroaryl halides in the transformation. The initial scope of aryl halides and limitations of this methodology are presented.