Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201306297 | DOI Listing |
Org Lett
January 2025
Taizhou Research Institute, Southern University of Science and Technology, Taizhou 318014, Zhejiang, China.
Organocatalytic enantioselective formal nucleophilic substitution reactions of α-(2-hydroxynaphthalen-8-yl)propargyl alcohols with 1-(1-indol-3-yl)naphthalen-2-ols have been established for the first time. With the aid of a suitable chiral phosphoric acid, alkynyl 8-methylenenaphthalen-2(8)-one was formed in situ from the corresponding α-(2-hydroxynaphthalen-8-yl)propargyl alcohol, followed by enantioselective 1,6-conjugate additions of 1-(1-indol-3-yl)naphthalen-2-ols to afford a number of enantioenriched (,)-2,3-disubstituted indoles in 50-80% yields with 81-93% ee and (,)-2,3-disubstituted indoles in 18-40% yields with 79-96% ee. Notably, these nucleophilic substitution products were characterized by the presence of functional groups, including indole, naphthol, and alkynyl units, while exhibiting both axial and central chirality.
View Article and Find Full Text PDFMolecules
January 2025
Institute for Organic Synthesis and Photoreactivity of the Italian National Research Council, Area della Ricerca di Bologna, Via P. Gobetti, 101, 40129 Bologna, Italy.
The utilization of the homogeneous ()-2-pyrrolidine-tetrazole organocatalyst (Ley catalyst) in the self-condensation of ethyl pyruvate and cross-aldol reactions of ethyl pyruvate donor with non-enolizable pyruvate acceptors, namely the sterically hindered ethyl 3-methyl-2-oxobutyrate or the highly electrophilic methyl 3,3,3-trifluoropyruvate, is described as the key enantioselective step toward the synthesis of the corresponding biologically relevant isotetronic acids featuring a quaternary carbon functionalized with ester and alkyl groups. The transition from homogeneous to heterogeneous flow conditions is also investigated, detailing the fabrication and operation of packed-bed reactors filled with a silica-supported version of the pyrrolidine-tetrazole catalyst (SBA-15 as the matrix).
View Article and Find Full Text PDFMolecules
January 2025
Laboratoire de Chimie Agro-Industrielle (LCA), Université de Toulouse, INRAE, 4 allée Emile Monso, 31030 Toulouse, France.
In organic synthesis, the solvent is the chemical compound that represents the largest proportion of the process. However, conventional solvents are often toxic and dangerous for the environment, and an interesting alternative is to replace them by water. In this context, catalyst surfactants allow both organic reagents in water to be solubilized and organic reactions to be catalyzed.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Memorial University, St. John's, Newfoundland and Labrador A1B 3X7, Canada.
Organocatalytic, enantioselective decarboxylative Mannich reactions of α,β-unsaturated β'-ketoacids and isatin -Boc imines, to give the corresponding 3-carbamoyl-2-oxindole derivatives, were developed. Subsequent N-deprotection and diastereoselective, intramolecular, aza-Michael reaction of the free amine provides previously unreported spiro[indoline-3,2'-piperidine]-2,4'-diones.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States.
Chiral medium-sized rings, albeit displaying attractive properties for drug development, suffer from numerous synthetic challenges due to difficult cyclization steps that must take place to form these unusually strained, atropisomeric rings from sterically crowded precursors. In fact, catalytic enantioselective cyclization methods for the formation of chiral seven-membered rings are unknown, and the corresponding eight-membered variants are also sparse. In this work, we present a substrate preorganization-based, enantioselective, organocatalytic strategy to construct seven- and eight-membered rings featuring chirality that is intrinsic to the ring in the absence of singular stereogenic atoms or single bond axes of chirality.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!