The asymmetric synthesis of functionalized nitrocyclopropanes has been achieved by a one-pot, four-step method catalyzed by (S)-diphenylprolinol TMS ether, which joins two sequential domino reactions, namely a domino sulfa-Michael/aldol condensation of α,β-unsaturated aldehydes with 1,4-dithiane-2,5-diol, and a domino Michael/α-alkylation reaction of the derived chiral dihydrothiophenes with bromonitromethane. The title compounds were obtained in 27-45% yields, with high levels of diastereoselectivity (93:7 to 100:0 dr) and generally good enantioselectivities (up to 95:5 er).
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http://dx.doi.org/10.1021/acs.joc.5b01607 | DOI Listing |
J Am Chem Soc
December 2024
Department of Chemistry, University of Wyoming, Laramie, Wyoming 82071, United States.
Functionalizing graphene with exact pore size, specific functional groups, and precision doping poses many significant challenges. Current methods lack precision and produce random pore sizes, sites of attachment, and amounts of dopant, leading to compromised structural integrity and affecting graphene's applications. In this work, we report a strategy for the synthesis of functionalized graphitic materials with modifiable nanometer-sized pores via a Pictet-Spengler polymerization reaction.
View Article and Find Full Text PDFMolecules
October 2024
Technological Institute of Materials & Energy Science (TIMES), Xijing University, Xi'an 710123, China.
A novel ()-1-(4-methylbenzylidene)-4-(3-isopropylphenyl) thiosemicarbazone was synthesized in a one-pot four-step synthetic route. Fourier transform infrared spectroscopy (FTIR), H and C nuclear magnetic resonances (NMR), single-crystal X-ray diffraction, and UV-visible absorption spectroscopy were utilized to confirm the successful preparation of the title compound. Single-crystal data indicated that the intramolecular hydrogen bond N(3)-H(3)···N(1) and intermolecular hydrogen bond N(2)-H(2)···S(1) (1 - x, 1 - y, 1 - z) existed in the crystal structure and packing of the title compound.
View Article and Find Full Text PDFEJNMMI Radiopharm Chem
June 2024
Cyclotron Radiochemistry Facility, The University of Texas MD Anderson Cancer Center, Houston, TX, 77054, USA.
Background: 4-[F]fluorobenzyl-triphenylphosphonium ([F]FBnTP) is a lipophilic cation PET tracer. The cellular uptake of [F]FBnTP is correlated with oxidative phosphorylation by mitochondria, which has been associated with multiple critical diseases. To date, [F]FBnTP has been successfully applied for imaging myocardial perfusion, assessment of severity of coronary artery stenosis, delineation of the ischemic area after transient coronary occlusion, and detection/quantification of apoptosis in various animal models.
View Article and Find Full Text PDFOrg Biomol Chem
May 2024
Department of Optoelectronics and Nanostructure Science, Graduate School of Science and Technology, Shizuoka University, 3-5-1 Johoku, Hamamatsu 432-8561, Shizuoka, Japan.
Fairy chemicals (FCs), such as 2-azahypoxanthine (AHX), are a potential new class of plant hormones that are naturally present in plants and produced a novel purine metabolic pathway. FCs support plant resilience against various stresses and regulate plant growth. In this study, we developed a four-step method for synthesising AHX from 2-cyanoacetamide, achieving a good yield.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2024
Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan.
A reductive (3+2) annulation of lactams through iridium-catalyzed hydrosilylation and photoredox coupling with α-bromoacetic acid was developed. The iridium-catalyzed hydrosilylation of the lactam carbonyl group and subsequent elimination provide a transient cyclic enamine, which undergoes iridium-catalyzed photoredox coupling with α-bromoacetic acid in a one-pot process. The developed conditions show high functional-group tolerance and provide cyclic N,O-acetals containing a quaternary carbon center.
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