We report herein the enantioselective photoinduced Nazarov reaction using a relay strategy of an electrocyclization, followed by parallel kinetic resolution (PKR). No enantioselectivity was observed during electrocyclization due to weak coordination between chiral ligands and the substrate's carbonyl group. However, PKR was successfully achieved in the deprotonation step with a bifunctional chiral thiourea ligand. Regioselective deprotonation, controlled by the chiral -dimethyl amine motif, produced -6,5,6-fused tricyclic stereoisomers with high ee and yields.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.orglett.4c04177 | DOI Listing |
Nat Commun
December 2024
Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Marine cyclopianes are a family of diterpenoid with novel carbon skeleton and diverse biological activities. Herein, we report our synthetic and chemical proteomics studies of cyclopiane diterpenes which culminate in the asymmetric total synthesis of conidiogenones C, K and 12β-hydroxy conidiogenone C, and identification of Immunity-related GTPase family M protein 1 (IRGM1) as a cellular target. Our asymmetric synthesis commences from Wieland-Miescher ketone and features a sequential intramolecular Pauson-Khand reaction and gold-catalyzed Nazarov cyclization to rapidly construct the 6-5-5-5 tetracyclic skeleton.
View Article and Find Full Text PDFNanomaterials (Basel)
November 2024
Department of Orthopaedics and Rehabilitation Medicine, Tufts University School of Medicine, Boston, MA 02111, USA.
3D-printed microporous titanium scaffolds enjoy good biointegration with the residuum's soft and bone tissues, and they promote excellent biomechanical properties in attached prostheses. Implant-associated infection, however, remains a major clinical challenge. Silver-based implant coatings can potentially reduce bacterial growth and inhibit biofilm formation, thereby reducing the risk of periprosthetic infections.
View Article and Find Full Text PDFEuropean J Org Chem
November 2024
Department of Chemistry, University of Rochester, Rochester, NY 14627.
This manuscript describes a study of diverse reaction outcomes that stem from the ionization of -alkynyl-Prins adducts. Experimental results have demonstrated unexpected behavior in the nitrogen-containing systems compared to the analogous oxygen derivatives derived from -Prins/-Nazarov sequences. In-depth experimental studies and computational analysis revealed an intricate mechanism involving competing -Nazarov and -Nazarov pathways.
View Article and Find Full Text PDFOrg Lett
December 2024
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State Key Laboratory of Petroleum Molecular & Process Engineering, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai 200050, China.
We report herein the enantioselective photoinduced Nazarov reaction using a relay strategy of an electrocyclization, followed by parallel kinetic resolution (PKR). No enantioselectivity was observed during electrocyclization due to weak coordination between chiral ligands and the substrate's carbonyl group. However, PKR was successfully achieved in the deprotonation step with a bifunctional chiral thiourea ligand.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
October 2024
Laboratory of Catalysis and Organic Synthesis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, CH-1015, Lausanne, Switzerland.
We report herein our studies on the direct photoactivation of carbonyl cyclopropanes to give biradical intermediates, leading to selective cleavage of the more substituted carbon-carbon bond. Depending on the substrate structure, extended alkenes were isolated or directly reacted in a photo-Nazarov process to give bicyclic products. Based on these results, a unified reductive ring-opening reaction was developed by using diphenyl disulfide as a hydrogen atom transfer (HAT) reagent.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!