Vinyl sulfones are privileged motifs known for their biological activity and synthetic utility. Synthetic transformations to efficiently access high-value compounds with these motifs are desired and sought after. Herein, a new procedure is described to form vinyl sulfone-containing compounds by selective functionalization of the C(sp)-H bond adjacent to the pyridine ring of pharmacologically prevalent picolyl amides with an allenyl sulfone, 1-methyl-4-(propa-1,2-dien-1-ylsulfonyl)benzene. The reaction conditions are mild with no metal catalyst or additives required and display good functional group tolerance. Mechanistic studies for this unusual transformation suggest that the reaction operates via a rare pyridine-initiated and -toluenesulfinate anion-mediated activation of the allenyl sulfone analogous to phosphine-triggered reactions.
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http://dx.doi.org/10.1021/acs.joc.0c00788 | DOI Listing |
J Org Chem
October 2024
Department of Organic Chemistry, Indian Institute of Science, Bangalore 560012, India.
The addition of lithiated allenyl sulfones to nonracemic sulfinimines furnished sulfinamides possessing the allenyl sulfonyl moiety with excellent diastereoselectivity. The formed products are transformed into different heterocycles, including the synthesis of pyrroline, pyran, and functionalized benzopyran.
View Article and Find Full Text PDFChem Sci
August 2024
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University Lanzhou 730000 P. R. China
The radical-mediated difunctionalization of 1,3-enynes facilitates rapid access to structurally diverse allenes and dienes. Whereas, owing to the existence of multiple active sites in conjugated 1,3-enynes, regulating selectivity in difunctionalized addition a single transition-metal-catalyzed radical tandem process remains elusive. Herein, we disclose an intriguing protocol of substrate-controlled nickel-catalyzed regiodivergent sulfonylarylation of 1,3-enynes with the assistance of sulfonyl chlorides and arylboronic acids.
View Article and Find Full Text PDFJ Org Chem
May 2024
Institute of Organic Chemistry, Jiangxi Science & Technology Normal University, Key Laboratory of Organic Chemistry, Nanchang, Jiangxi 330013, China.
A novel conversion of 1,5-diynols into sulfonylated benzo[]fluorenes is reported by a TFA-promoted cascade cyclization with sodium sulfinates under mild conditions. This strategy provides an efficient and practical approach for accessing various sulfonated benzo[]fluorenes in moderate to excellent yields under metal-free conditions. On the basis of the control experimental results and density functional theory calculations, a possible cascade transformation mechanism consisting of the dehydration of propargylic alcohols, sulfonylation, allenylation, and Schmittel-type cyclization is proposed.
View Article and Find Full Text PDFJ Org Chem
November 2022
School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
A regio- and chemoselective sulfonylation of propargyl alcohols with sulfinamides in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) was developed. It provided straightforward and mild access to multi-substituted allenyl sulfones by using sulfinamides as the sulfonyl sources. This transformation was promoted by HFIP and did not require any catalysts or oxidants, which allowed for the successful conversion of various tertiary and secondary propargyl alcohols into allenyl sulfones in high yields.
View Article and Find Full Text PDFOrg Biomol Chem
November 2022
Department of Environmental Sciences, Faculty of Natural Resources and Marine Sciences, Tarbiat Modares University, P.O. Box 46414-356, Noor, Iran.
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