We herein report a protocol for the asymmetric aldol-initiated cascade addition of isoxazolidin-5-ones to -cyanobenzaldehydes by using 's bifunctional organocatalyst. This approach allows for the synthesis of various novel β-amino acid-phthalide conjugates with good enantio- and diastereoselectivities in reasonable yields and the further ring-opening of these compounds to acyclic carboxylic acid derivatives was demonstrated too.
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http://dx.doi.org/10.1002/hlca.202200110 | DOI Listing |
J Am Chem Soc
January 2025
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden.
Direct cross-coupling reactions between two similar unactivated partners are challenging but constitute a powerful strategy for the creation of new carbon-carbon bonds in organic synthesis. [4]Dendralenes are a class of acyclic branched conjugated oligoenes with great synthetic potential for the rapid generation of structural complexity, yet the chemistry of [4]dendralenes remains an unexplored field due to their limited accessibility. Herein, we report a highly selective palladium-catalyzed oxidative cross-coupling of two allenes with the presence of a directing olefin in one of the allenes, enabling the facile synthesis of a broad range of functionalized [4]dendralenes in a convergent modular manner.
View Article and Find Full Text PDFJ Org Chem
January 2025
Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53233, United States.
Acrylic nitriles are a versatile class of synthetic precursors for a variety of pharmaceutically active compounds, as well as for nitrile polymers. We devised a stereoselective synthesis of ()-acrylic nitriles from the Ru-catalyzed coupling reaction of nitriles with unsaturated carbonyl compounds via C-C bond cleavage. Both carbon KIE and Hammett correlation data indicated that C-C bond cleavage is the rate-determining step for the coupling reaction.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Pharmacy, Sungkyunkwan University, Suwon 16419, Republic of Korea.
The stereoselective synthesis of highly substituted cyclobutanes is essential for the development of lead candidates in drug discovery. Herein, we present a novel Rh(III)-catalyzed reaction pathway for synthesizing substituted cyclobutanes, which involves a concerted N-C bond formation and C-C bond cleavage between 2-aryl quinazolinones and alkylidenecyclopropanes. Notably, the combination of Rh(III) catalyst and HFIP solvent plays a critical role in facilitating the formation of cyclobutane rings.
View Article and Find Full Text PDFNat Commun
January 2025
Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai, PR China.
Allylic ethers and alcohols are essential structural motifs commonly present in natural products and pharmaceuticals. Direct allylic C-H oxygenation of internal alkenes is one of the most direct methods, bypassing the necessity for an allylic leaving group that is needed in the traditional Tsuji-Trost reaction. Herein, we develop an efficient and practical method for synthesizing (E)-allyl ethers from readily available internal alkenes and alcohols or phenols via selective allylic C-H oxidation.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, Vienna, A-1190 Austria.
Chemical 1,1'-glycosylation for the synthesis of non-reducing disaccharides is complicated by the need to simultaneously control the stereochemistry at two anomeric centers. While considerable progress has been made in the synthesis of α,α-disaccharides, the assembly of 1,1'-β,β- and 1,1'-β,α-linked non-reducing sugars has received comparatively less attention. Many naturally occurring non-reducing disaccharides and their biologically active mimetics feature asymmetrically located functional groups at different positions on the two pyranose rings, highlighting the demand for reliable stereoselective methods to synthesize fully orthogonally protected 1,1'-conjugated sugars suitable for targeted functionalisation to create important biomolecules.
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