Highly asymmetric (3+3) annulation of diaziridines with oxiranes via C-N bond cleavage in diaziridine was achieved under 10 mol % of chiral copper(II) complex as the catalyst under mild reaction conditions. With Cu(OTf) as the Lewis acid and C-symmetric imidazolidine-pyrroloimidazolone pyridine as the ligand, diverse tetrahydro-[1,3,4]-oxadiazines were obtained by stereospecific C-N/C-O bond formation in moderate to good yields (up to 93% yield) and high diastereo- (>20:1 dr) and enantioselectivities (up to 92% ee). The catalytic cycle and stereochemical model were proposed by DFT calculation.
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http://dx.doi.org/10.1021/acs.orglett.5c00064 | DOI Listing |
J Am Chem Soc
January 2025
National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, P. R. China.
Due to their strong aromaticity and difficulties in chemo-, regio-, and enantioselectivity control, asymmetric hydrogenation of naphthol derivatives to 1,2,3,4-tetrahydronaphthols has remained a long-standing challenge. Herein, we report the first example of homogeneous asymmetric hydrogenation of naphthol derivatives catalyzed by tethered rhodium-diamine catalysts, affording a wide array of optically pure 1,2,3,4-tetrahydronaphthols in high yields with excellent regio-, chemo-, and enantioselectivities (up to 98% yield and >99% ee). Mechanistic studies with experimental and computational approaches reveal that fluorinated solvent 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) plays vital roles in the control of reactivity and selectivity, and 1-naphthol is reduced via a cascade reaction pathway, including dearomative tautomerization, 1,4-hydride addition, and 1,2-hydride addition in sequence.
View Article and Find Full Text PDFOrg Lett
January 2025
State Key Laboratory of Antiviral Drugs, Pingyuan Laboratory, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China.
Highly asymmetric (3+3) annulation of diaziridines with oxiranes via C-N bond cleavage in diaziridine was achieved under 10 mol % of chiral copper(II) complex as the catalyst under mild reaction conditions. With Cu(OTf) as the Lewis acid and C-symmetric imidazolidine-pyrroloimidazolone pyridine as the ligand, diverse tetrahydro-[1,3,4]-oxadiazines were obtained by stereospecific C-N/C-O bond formation in moderate to good yields (up to 93% yield) and high diastereo- (>20:1 dr) and enantioselectivities (up to 92% ee). The catalytic cycle and stereochemical model were proposed by DFT calculation.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Organisch-Chemisches Institut, Universität Münster, Corrensstraße 40, Münster 48149, Germany.
Asymmetric synthesis presents many challenges, with the selective formation of chiral bridged polyheterocycles being a notable example. Cycloadditions using bicyclo[1.1.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Graduate School of Science, Osaka Metropolitan University, 3-3-138 Sumiyoshi-ku, Osaka 558-8585, Japan.
The asymmetric total synthesis of isolinearol, a -dolastane-type diterpenoid that inhibits byssal thread formation by mussels, has been achieved. In the synthesis, the key features include an intramolecular reductive nucleophilic addition using a low-valence titanium species and the direct installation of a ketone side chain. We evaluated their biological activities using the synthetic samples and found the novel inhibitory molecules with a simplified structure exhibit high inhibitory activities against byssus formation and low toxicities.
View Article and Find Full Text PDFJ Org Chem
January 2025
Antibiotics Research and Re-evaluation Key Laboratory of Sichuan Province, Sichuan Industrial Institute of Antibiotics, School of Pharmacy, Chengdu University, 2025 Chengluo Avenue, Chengdu 610016, P. R. China.
We report a highly regioselective 1,2-addition of P(O)-H compounds to the in situ generated β,γ-alkynyl-α-ketimine derived from 3-alkynyl-3-hydroxyisoindolinones, which provided a general protocol for the preparation of 3,3-disubstituted isoindolinones featuring both phosphoryl and alkynyl groups at a quaternary carbon center. The use of only 2-5 mol % of an inexpensive catalyst (In(ClO)·8HO or Bi(OTf)) allowed the smooth output of the desired products under mild conditions (25 °C, 0.5-24 h) with a broad substrate scope (35 examples) in up to >99% yield.
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