A one-carbon homologation of Knoevenagel adducts enabling the insertion of a CHAr fragment is reported. The strategy involves a sulfur ylide mediated cyclopropanation followed by the rearrangement of cyclopropanes and enables the synthesis of a series of benzhydryl derivatives. Mechanistic studies reveal that the cyclopropane rearrangement involves a Lewis acid catalyzed ring-opening followed by the 1,2-migration of an aryl group. The possibility of controlling the absolute stereochemistry of the generated stereogenic allylic carbon center using a chiral sulfonium ylide is demonstrated.
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http://dx.doi.org/10.1021/acs.joc.4c00057 | DOI Listing |
J Am Chem Soc
December 2024
The GSK Carbon Neutral Laboratories for Sustainable Chemistry, University of Nottingham, Jubilee Campus, Nottingham NG7 2TU, United Kingdom.
The one-carbon homologation of carboxylic acids is a valuable route to construct families of homologues, which play fundamental roles in chemistry and biology. However, known procedures are based on multistep sequences, use harsh conditions or are limited in scope. Thus, almost a century after the discovery of the original Arndt-Eistert homologation sequence, a general method to directly convert carboxylic acids into their corresponding homologues remains elusive.
View Article and Find Full Text PDFBeilstein J Org Chem
August 2024
Graduate Faculty of Interdisciplinary Research, University of Yamanashi, 4-4-37 Takeda, Kofu 400-8510, Japan.
Isocyanide is a promising synthetic reagent not only as a one-carbon homologation reagent but also as a nitrogen source for nitrogen-containing molecules. Because of their isoelectronic structure with carbon monoxide, isocyanides also react with nucleophiles, electrophiles, carbon radicals, and transition metal reagents, and are widely used in organic synthesis. On the other hand, the use of isocyanides in reactions with heteroatom radicals is limited.
View Article and Find Full Text PDFAnticancer Res
September 2024
Laboratory of Bio-organic Chemistry, Akita Prefectural University, Akita, Japan.
Background/aim: Flavonoids represent a privileged scaffold for medicinal chemists because of versatile synthetic transformation into a large variety of functionalized derivatives and are known to exhibit a variety of biological activities and their potential as anticancer agents is being investigated. As part of our continuing investigation of flavonoid derivatives as potential anticancer substances, a series of 3-methylflavones were synthesized, and their antiproliferative activity was evaluated in leukemic HL60 cells.
Materials And Methods: 3-Methylflavones were directly synthesized from the 2-propionylphenyl benzoate esters prepared from combination of 2'-hydroxypropiophenone with appropriate benzoic acid derivatives by the modified conditions of Yamaguchi esterification.
ACS Omega
June 2024
Marine Natural Products Chemistry Laboratory, Korea Institute of Ocean Science and Technology (KIOST), Busan 49111, Republic of Korea.
Herein, we report the first- and second-generation syntheses of (+)-ieodomycins A and B and their stereoisomers via the late-stage elaboration of their conjugated -diene side chains. Key steps for successful synthesis included Keck asymmetric allylation to introduce a hydroxyl group at the C5 position, consecutive Wipf's carboalumination modification, iodination, Sharpless asymmetric dihydroxylation, one-carbon homologation via cyanation, Mukaiyama lactonization, and Stille cross-coupling to form the conjugated -diene moiety. Further, the preliminary bioactivity profile against various disease-related molecular targets and cell lines was investigated.
View Article and Find Full Text PDFJ Org Chem
May 2024
Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Place Louis Pasteur 1 box L4.01.02, 1348 Louvain-la-Neuve, Belgium.
A one-carbon homologation of Knoevenagel adducts enabling the insertion of a CHAr fragment is reported. The strategy involves a sulfur ylide mediated cyclopropanation followed by the rearrangement of cyclopropanes and enables the synthesis of a series of benzhydryl derivatives. Mechanistic studies reveal that the cyclopropane rearrangement involves a Lewis acid catalyzed ring-opening followed by the 1,2-migration of an aryl group.
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