Results 141 to 150 of about 42,305 (289)

Biocatalytic Synthesis of Isoxazolines Enabled by Cryptic Nitrile Oxide Formation by a Vanadium‐Dependent Chloroperoxidase

Angewandte Chemie, EarlyView.
The vanadium‐dependent haloperoxidase (VHPO) class of enzymes has been shown to catalyze cryptic nitrile oxide generation in an oxidative [3+2] cycloaddition reaction between aldoximes and alkenes to generate isoxazolines. This biotechnology has been applied to a chemoenzymatic sequence starting from aldehydes through in situ condensation with ...
Manik Sharma, Kyle F. Biegasiewicz
wiley   +2 more sources

Continuous N-alkylation reactions of amino alcohols using γ-Al2O3 and supercritical CO2: unexpected formation of cyclic ureas and urethanes by reaction with CO2

Beilstein Journal of Organic Chemistry, 2017
The use of γ-Al2O3 as a heterogeneous catalyst in scCO2 has been successfully applied to the amination of alcohols for the synthesis of N-alkylated heterocycles.
Emilia S. Streng, Darren S. Lee, Michael W. George, Martyn Poliakoff   +3 more
doaj   +1 more source

Navigating Nitration Chemistry: A Practical Guide to Reagents, Mechanisms, and Selectivity

Angewandte Chemie, EarlyView.
This review highlights key contributions of modern nitration chemistry, emphasizing sustainable mechanistic platforms and comparing the performance of both organic and inorganic reagents across aromatic, ipso‐, olefin, alkyne, and heteroatom nitration. It provides the community with a clearer, unified perspective on current advances and facilitates the
Harry Lecomte, Anthony J. Fernandes, Dmitry Katayev   +2 more
wiley   +2 more sources

Nickel‐Catalyzed Enantioconvergent Arylation of Unactivated Cyclic Electrophiles: Asymmetric Synthesis of 3‐Substituted Pyrrolidines

Angewandte Chemie, EarlyView.
Metal‐catalyzed enantioconvergent substitutions of unactivated cyclic electrophiles by organometallic nucleophiles have not previously been reported. Herein, a chiral nickel catalyst is described that achieves this objective, coupling 3‐iodopyrrolidine derivatives with arylzinc nucleophiles.
Ting Hei Matthew Wong, Xiaoyu Tong, Gregory C. Fu   +2 more
wiley   +2 more sources

Crystal Structure of 4′-Phenyl-1′,4′-Dihydro-2,2′:6′,2″-Terpyridine: An Intermediate from the Synthesis of Phenylterpyridine

Crystals
The intermediate compound 4′-phenyl-1′,4′-dihydro-2,2′:6′,2″-terpyridine (pdhtpy) was isolated for the first time during the synthesis of 4′-phenyl-2,2′:6′,2″-terpyridine (ptpy) and characterised by single-crystal X-ray diffraction.
Alexander Sedykh, Maksim Zhernakov, Mariia Becker, Dirk G. Kurth, Klaus Müller-Buschbaum   +4 more
doaj   +1 more source

Diazo Transfer From Nitrous Oxide Employing Phosphorus Ylides

Angewandte Chemie, EarlyView.
A phosphorus ylide‐mediated strategy achieves the direct fixation of nitrous oxide (N2O) to access diazo compounds, which after intra‐ or intermolecular trapping, afford N2‐containing organic building blocks. This approach provides an alternative to hazardous diazo‐transfer reagents and establishes N2O fixation as a sustainable methodology.
Jhen‐Kuei Yu, Jan Niclas Ludwig, Patrick Wolf Antoni, David Tymann, Max Martin Hansmann   +4 more
wiley   +2 more sources

Azide‐to‐Diazo Transformation Facilitated by Michael Addition via Phosphazide Formation

Angewandte Chemie, EarlyView.
A new type of Michael addition based on azide‐to‐diazo conversion is disclosed. This unusual transformation proceeds via 1,4‐addition accompanied by N─N bond cleavage of phosphazide intermediates under practical conditions. The high versatility of the resulting Michael adducts enables the synthesis of a wide variety of organonitrogen compounds ...
Tomoki Mano, Takahiro Yasuda, Gaku Orimoto, Suguru Yoshida   +3 more
wiley   +2 more sources

Sulfur‐Directed Construction of Vinyl Cyclopropanes from 1,3‐Dienes

Angewandte Chemie, EarlyView.
Sulfur takes control. A pending thioether acts as a molecular compass, directing carbene addition to the 1,3‐diene scaffold with exceptional regio‑ and diastereocontrol to forge sulfur‐substituted vinyl cyclopropanes (S‐VCPs) — molecular architectures inaccessible via conventional cyclopropanation strategies.
Anna Keimer, Jonas Rettig, Tim‐Niclas Streit, Bob Barthel, Mélissa Calmels, Moritz Malischewski, Franz‐Lucas Haut   +6 more
wiley   +2 more sources

Hydrogen Isotope Exchange in Pyridine Catalyzed by an Iron(II) Imido Complex: Counterion‐Directed Regioselectivity

Angewandte Chemie, EarlyView.
Anionic high‐spin iron(II) imido complexes are catalysts for the hydrogen isotope exchange (HIE) reaction with pyridine as the substrate. The alkali metal counter‐cation plays critical roles in activating the substrate and facilitating deuteration. These complexes catalyze site‐selective α‐, α,β,γ‐, and β,γ‐deuteration of pyridine, where the counter ...
Bin Feng, Guorong Li, Yafei Gao, Nobuyuki Yamamoto, Maren Pink, Qian Peng, Jeremy M. Smith   +6 more
wiley   +2 more sources

Radical-Mediated Anti-Markovnikov Hydrophosphonation of Olefins [PDF]

, 2011
The radical-mediated addition of triphenylphosphonium tetrafluoroborate to olefins (hydrophosphonation) is reported. Both standard radical initiators and photochemical conditions are effective, up to the gram scale.
Daeffler, Christopher S., Grubbs, Robert H.   +1 more
core   +1 more source