A new catalytic enantioselective hydroarylation of unactivated olefins is developed that provides rapid access to functionalized chiral dihydrobenzofurans with good yields and excellent enantioselectivities. Simple aromatic ketones or amides act as a directing group allowing the regioselective reaction at the more hindered ortho position. Tertiary benzylic stereocenters are obtained directly under mild reaction conditions and with complete atom economy from readily available starting materials.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.202001793 | DOI Listing |
Tetrahedron Lett
October 2024
Department of Chemistry, University of California, Berkeley, CA 94720, USA.
Neutral dual hydrogen bond donors (HBDs) are effective catalysts that enhance the electrophilicity of substrates or the Lewis/Brønsted acidity of reagents through an anion-binding mechanism. Despite their success in various enantioselective organocatalytic reactions, their application to transition metal catalysis remains rare. Herein, we report the activation of gold(I) precatalysts by chiral ureas, leading to enantioselective hydroarylation of allenes with indoles.
View Article and Find Full Text PDFJ Am Chem Soc
July 2024
Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States.
Herein, we report room temperature, atom-economic protocols for high regio- and enantioselective tandem cycloisomerization-hydroarylation and cycloisomerization-hydroalkenylation of 1,6-enynes leading to vicinal -functionalized pyrrolidines, tetrahydrofurans, and cyclopentanes. The latter steps in these processes involve carbonyl-coordination-assisted C-H activation of aromatic aldehydes and esters, and, a similar, yet rarely seen, β-C-H activation in the case of the acrylates. Synthetically useful enantioselective versions of such reactions are rare and are limited to the C-H activation of indoles and pyrroles.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
July 2024
Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2, Canada.
Metal-catalyzed enantioselective conjugate arylations of electron-poor alkenes are highly selective processes for C(sp)-C(sp) bond formation. δ-Selective hydroarylations of electron-poor 1,3-dienes are less well developed and reactions that deliver high enantioselectivity while giving single alkene isomer products are elusive. Here we report the Rh-catalyzed δ-arylation of aryl-substituted 1,3-dienes that gives nearly exclusive Z-1,4-addition products (generally with >95 : 5 positional and geometrical selectivity).
View Article and Find Full Text PDFJ Am Chem Soc
May 2024
Research Center for Molecular Recognition and Synthesis, Department of Chemistry, Fudan University, 220 Handan Lu, Shanghai 200433, China.
Aliphatic strained rings have been increasingly applied in medicinal chemistry due to their beneficial physicochemical and pharmacokinetic properties. However, the divergent synthesis of enantioenriched cyclobutane derivatives with various structural patterns continues to be a significant challenge. Here, we disclose a palladium-catalyzed enantioselective desymmetrization of cyclobutenes, resulting in a series of hydroarylation and 1,2- and 1,3-diarylation products via the interceptions of a common Heck intermediate.
View Article and Find Full Text PDFAdv Sci (Weinh)
June 2024
Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, 350207, China.
Chiral aldehydes containing a tertiary stereogenic center are versatile building blocks in organic chemistry. In particular, such structural motifs bearing an α,α-diaryl moiety are very challenging scaffolds and their efficient asymmetric synthesis is not reported. In this work, a phosphoric acid-catalyzed enantioselective synthesis of α,α-diaryl aldehydes from simple terminal alkynes is presented.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!