A novel and efficient cerium-catalyzed tandem oxidation and intermolecular ring cyclization of vicinal diols with hydrazones has been achieved for the regioselective synthesis of pyrazole derivatives. The corresponding 1,3-di- and 1,3,5-trisubstituted pyrazoles were obtained in moderate to excellent yields. The reaction has the advantages of mild conditions, easily available starting materials, broad substrate scope and good functional group tolerance.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d2ob01996e | DOI Listing |
Angew Chem Int Ed Engl
January 2025
University of Bari: Universita degli Studi di Bari Aldo Moro, Dept. of Pharmacy - Drug Sciences, via E. Orabona 4, 70125, Bari, ITALY.
Strained spiro-heterocycles (SSH) have gained significant attention within the medicinal chemistry community as promising (sp3)-rich bioisosteres for their aromatic and non-spirocyclic counterparts. We herein report access to an unprecedented spiro-heterocycle - 1,5-dioxaspiro[2.3]hexane.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Korea.
1,4-Dihydronicotinamide adenine dinucleotide (NADH) and its phosphate ester (NADPH) are essential cofactors required for all living cells, playing pivotal roles in multiple biological processes such as energy metabolism and biosynthesis. NADPH is produced during photosynthesis by the combination of photosystem II, where water is oxidised, and photosystem I, where NADP is reduced. This review focuses on catalytic NAD(P) (and its analogues) reduction to generate 1,4-NAD(P)H without formation of other regioisomers and the dimer.
View Article and Find Full Text PDFCarbohydr Res
January 2025
Glycochemistry Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi, 110067, India. Electronic address:
Glycohybrids are biologically significant molecules with variety of biological functions and are found as structural motifs in numerous natural products. Here, we report the synthesis of various new coumarin-based O-glycoconjugates as glycohybrids that are chirally enriched and bridged by 1,2,3-triazoles ring system. The1,2,3-triazoles bridging was done via CuAAC click-chemistry.
View Article and Find Full Text PDFOrg Lett
January 2025
Engineering Research Center of Ministry of Education for Fine Chemicals, Shanxi University, Taiyuan 030006, P. R. of China.
Herein a novel and robust methodology to spiroimidazolidinones has been developed under a mild reaction. The reaction of (Z)-2-azido-3-phenylacrylic acids , aldehydes , amines , isocyanides , and isocyanides produced regioselectively spiroimidazolidinones in 71-88% yields via a sequential Ugi 4CR/Pd(0) catalyzed azide-isocyanide coupling/cyclization/rearrangement/hydroxylation reaction. Furthermore, the easily accessible starting materials, high bond-forming efficiency, and broad substituent tolerance make this strategy useful in synthetic and medicinal chemistry.
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.
Herein, we report the first example that P(O)-H species including -phosphonates and -phosphine oxides could participate in a highly regioselective 1,4-addition to in situ generated 1-benzopyrylium ion from C3-substituted 2-chromene hemiketals, which provides a brand-new and effective approach for the synthesis of C4-phosphorylated 4-chromenes with diverse C3-functionality (ketone, ester, sulfonyl, aryl, and alkyl groups). In total, the reaction features the use of inexpensive Zn(ClO)·6HO as a catalyst, low catalyst loading (only 5 mol %), mild reaction conditions (60 °C, 10 min to 24 h), and broad substrate scope (46 examples) as well as good to high yields (>90% yield on average). More importantly, mechanistic experiments demonstrated the essential role of the C3-substituent on 2-chromene hemiketals in stabilizing the in situ generated 1-benzopyrylium ion and the regioselective 1,4-addition control.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!