Article
Chemistry, Organic
Kohei Nakamura, Eiji Kobayashi, Katsuhiko Moriyama, Hideo Togo
Summary: Treatment of anti alkyl o-biaryl ketoximes and anti aryl o-biaryl ketoximes with Tf2O at 120 degrees C, followed by quenching with Et3N, resulted in good yields of 6-alkylphenanthridines and 6-arylphenanthridines, respectively. These reactions involve O-triflation of ketoximes, Beckmann rearrangement, and electrophilic cyclization onto the aromatic ring of the formed nitrilium group.
Article
Chemistry, Organic
Tomohiro Maegawa, Ryohei Oishi, Ayumi Maekawa, Kazutoshi Segi, Hiromi Hamamoto, Akira Nakamura, Yasuyoshi Miki
Summary: We investigated the reaction of ketoximes with hypervalent iodine reagents and found that a combination of PhI(OAc)(2) and BF3 center dot Et2O promoted the Beckmann rearrangement of ketoximes, forming the corresponding amides. Additionally, we determined that the Beckmann rearrangement is preceded by the in situ acetylation of the hydroxy group of the ketoxime, and confirmed that the acetylated ketoxime undergoes the Beckmann rearrangement with BF3 center dot Et2O. We also discovered that the reaction of ketoximes with Koser's reagent [PhI(OH)OTs] in the presence of tetrahydrofuran resulted in hydrolysis, yielding the corresponding ketones in high yields at room temperature.
SYNTHESIS-STUTTGART
(2022)
Article
Chemistry, Multidisciplinary
Yangxu Du, Jiao Hou, Qing Lu, Wei Hao, Wenquan Yu, Junbiao Chang
Summary: A new synthetic method has been developed for the transformation of primary benzhydrylamines into aromatic secondary amine derivatives using an iodine-mediated 1,2-aryl migration reaction. The process is operationally simple and can be conducted successfully on a gram scale.
NEW JOURNAL OF CHEMISTRY
(2021)
Article
Chemistry, Organic
Xiangtai Meng, Dengfeng Chen, Rui Liu, Ping Jiang, Shenlin Huang
Summary: A novel synthesis method has been established for the production of 2-(cyanomethyl)benzoic esters from indanone derivatives, involving deprotonation of alcohols with a chemical base, nucleophilic addition to indanones, and Beckmann fragmentation. Interestingly, this reaction can also take place under electrochemical conditions without the need for external chemical bases. This mild method provides a new strategy for the late-stage functionalization of various natural alcohols.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
James A. Vogel, Kirya F. Miller, Eunjeong Shin, Jenna M. Krussman, Patrick R. Melvin
Summary: In this study, a modified Beckmann rearrangement using SIF reagents was employed to rapidly synthesize imidoyl fluoride intermediates. Amidine and imidate products were then formed by introducing amine and alcohol nucleophiles, respectively, under mild conditions. Approximately 50 amidine and imidate products have been isolated in high yields utilizing this method.
Article
Chemistry, Organic
Weiqiang Tan, Jifang Zheng, Le Chen, Huining Chai, Jing Guan
Summary: The efficient condensation and intramolecular cyclization of 1-hydroxyanthraquinone with various active methylene acetates mediated by Propylphosphonic anhydride (T3P) in the presence of Et3N leads to oxaperylenone derivatives. The reactive intermediate propylphosphate derivatives generated in situ from acylation of 1-hydroxyanthraquinone with T3P were confirmed. The study also proposed a plausible reaction mechanism based on density functional theory calculations. This method provides a useful approach for the synthesis of core structures of oxaperylenone derivatives.
Article
Chemistry, Applied
Dharm Dev, Tapasi Kalita, Tanmay Mondal, Bhubaneswar Mandal
Summary: This study reports a halogen-free organocatalytic Beckmann rearrangement method, which converts ketoximes to the corresponding amides/lactams. Detailed mechanistic investigation using NMR and mass spectrometry reveals that the rearrangement proceeds through two consecutive rearrangements.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Andrew Davidson, David A. Foley, Heather Frericks-Schmidt, Sally Gut Ruggeri, Madeline Herman, Shawn LaCasse, Yizhou Liu, Emma L. McInturff, Ronald Morris, Naila Mugheirbi, Brian Samas, Aritra Sarkar, Robert A. Singer, Faith Witkos, Shu Yu
Summary: Propylphosphonic anhydride, or T3P, is a commonly used reagent for amidation reactions with easy workup. This paper discusses the isolation and characterization of a T3P degradation byproduct and its removal by washing or further degradation at low pH. Another example shows the degradation of a T3P-related phosphonic ester at low pH.
ORGANIC PROCESS RESEARCH & DEVELOPMENT
(2021)
Article
Chemistry, Organic
Balint Toth, Timea Szabo, Balazs Volk, Matyas Milen
Summary: This study presents a novel synthesis method for N-(acyloxy)phthalimides and analogues using propylphosphonic anhydride as a reagent and 2-methyltetrahydrofuran as a green solvent under mild conditions. The technique offers a chromatography-free access to these synthetic intermediates with a wide substrate scope, allowing for the preparation of various alkyl, aryl, arylalkyl, and heteroaryl derivatives.
TETRAHEDRON LETTERS
(2022)
Article
Chemistry, Organic
Kosaku Tanaka Iii, Yoshimitsu Hashimoto, Nobuyoshi Morita, Osamu Tamura
Summary: Alkyl aldoximes without a directing group can react with aryl bromides to form alkyl aryl ketoximes. This reaction exhibits high yields, broad scope, and excellent functional group tolerance.
Article
Chemistry, Organic
Mike Ong, Marlene Arnold, Alexander W. Walz, Johannes M. Wahl
Summary: Amino diphenylphosphinates can undergo ring expansion of cyclobutanones to gamma-lactams under mild conditions, achieving a reaction pathway different from the common Beckmann reaction due to the ambivalent character of the aminating agent. The method exhibits high regioselectivity, stereospecificity, and chemoselectivity, making it suitable for late-stage skeletal editing.
Article
Chemistry, Medicinal
Antonella Ilenia Alfano, Sveva Pelliccia, Giacomo Rossino, Orazio Chianese, Vincenzo Summa, Simona Collina, Margherita Brindisi
Summary: In recent years, photochemistry has become increasingly important in academia and the pharmaceutical industry. Continuous-flow chemistry has helped overcome the issues of long photolysis times and light penetration reduction, making photochemical rearrangements more controlled and efficient. This article highlights the benefits of flow chemistry in photochemical rearrangements and showcases recent advances in the synthesis of pharmaceutically relevant substructures using photo-rearrangements in continuous flow.
ACS MEDICINAL CHEMISTRY LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Chieh-Hung Tien, Alan J. Lough, Andrei K. Yudin
Summary: The discovery and understanding of new reactions and high-energy states are crucial for advancing the field of chemistry and pushing the boundaries of organic synthesis.
Article
Chemistry, Multidisciplinary
Yongjiao Wei, Yinghui Liu, Lan-Gui Xie
Summary: The Beckmann rearrangement and following cascade reactions have been developed by using Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent. This method allows the conversion of various ketoximes into different compounds.
CHINESE CHEMICAL LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Qiang Zhang, Junyan Li, Xingxing Wang, Guangyuan He, Lin Li, Jun Xu, Donghai Mei, Osamu Terasaki, Jihong Yu
Summary: Zeolite nonclassical growth of MFI-type zeolite has been achieved using amorphous protozeolite nanoparticles as precursor. Silanol chemistry plays a critical role in determining precursor attachment behavior and crystal growth orientation. The attachment of platelet-like IPZ precursor on high-curvature surfaces with high-density silanols leads to the anisotropic rates of nonclassical growth and the formation of high-aspect-ratio zeolite nanosheets.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Geeta Devi Yadav, Pooja Chaudhary, Balaram Pani, Surendra Singh
Summary: Chiral transition metal complexes with privileged ligands are efficient catalysts for various asymmetric organic transformations. Transition metal complexes of C1-symmetric pyrrolidine-based ligands have been widely used in asymmetric organic reactions. However, a comprehensive review article on the transition metal complexes of chiral C1-symmetric pyrrolidine-based ligands derived from (L)-proline has not been published.
TETRAHEDRON LETTERS
(2024)
