Results 151 to 160 of about 105,486 (290)

Oxalates as Activating Groups for Alcohols in Visible Light Photoredox Catalysis: Formation of Quaternary Centers by Redox-Neutral Fragment Coupling. [PDF]

, 2015
Alkyl oxalates are new bench-stable alcohol-activating groups for radical generation under visible light photoredox conditions. Using these precursors, the first net redox-neutral coupling of tertiary and secondary alcohols with electron-deficient ...
Jamison, Christopher R, MacMillan, David WC, Nawrat, Christopher C, Overman, Larry E, Slutskyy, Yuriy   +4 more
core  

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

Cp2TiCl/D2O/Mn, a formidable reagent for the deuteration of organic compounds [PDF]

, 2016
Cp2TiCl/D2O/Mn is an efficient combination, sustainable and cheap reagent that mediates the D-atom transfer from D2O to different functional groups and can contribute to the synthesis of new deuterated organic compounds under friendly experimental ...
Rodríguez-García, Ignacio, Rosales Martínez, Antonio   +1 more
core   +1 more source

Convergent Total Synthesis of 16β‐Hydroxylpseudobufarenogin

Angewandte Chemie, EarlyView.
We present a novel convergent strategy that integrates Pd/Ag‐promoted Suzuki–Miyaura coupling with Ir‐catalyzed radical‐relay cyclization, enabling the first total synthesis of 16β‐hydroxylpseudobufarenogin. This approach is broadly applicable to the total synthesis of various oxygenated bufadienolides by simply modifying the fragment structures ...
Wataru Shigematsu, Yo Matsumoto, Koichi Hagiwara, Masayuki Inoue   +3 more
wiley   +2 more sources

Hydrobromination of alkenes with PBr3/SiO2: a simple and efficient regiospecific preparation of alkyl bromides

Journal of the Brazilian Chemical Society, 2001
The reaction of several alkenes with 0.4 mol equiv. PBr3/SiO2 in dichloromethane at room temperature gave the alkyl bromides with Markovnikov regiospecificity in 50 - 100% yield and short reaction time. Isoprene at - 8 °C in these conditions gave 1-bromo-
Sanseverino Antonio M., Mattos Marcio C.S. de   +1 more
doaj  

Cobalt‐Catalyzed Intramolecular C─H Silylation of Arenes

Angewandte Chemie, EarlyView.
Direct C─Si bond formation via C─H silylation is an atom‐economical route to organosilanes but is largely limited to noble metals. We report the first cobalt‐catalyzed intramolecular arene C–H silylation enabled by HCo(PMe3)4, which activates Si–H and C–H bonds to form diverse silacycles and silafluorenes in high yields with broad functional‐group ...
Yongqiang Xu, Valentin Poirier, Gilles Lemière, Julie Oble, Marc Petit   +4 more
wiley   +2 more sources

Kinetics of the reactions of laser-flash photolytically generated carbenium ions with alkyl and silyl enol ethers. Comparison with the reactivity toward alkenes, allylsilanes and alcohols [PDF]

, 1991
Bartl, Joerg, Mayr, Herbert, Steenken, Steen   +2 more
core   +1 more source

Bent N‐Heterocyclic Allenes From a Well‐Defined Titanium Vinylidene Complex

Angewandte Chemie, EarlyView.
The syntheses and the structures of N‐heterocyclic allenes are reported. Allenes bearing fluorenylidene capping groups show markedly bent C═C═C units, a carbene‐like reactivity, and they can act as potent C‐donor ligands for metal complexes. ABSTRACT Allenes typically display a linear geometry. A notable exception occurs in allenes bearing two electron‐
Bastiaan Kooij, Damien W. Chen, Rosario Scopelliti, Farzaneh Fadaei‐Tirani, Kay Severin   +4 more
wiley   +2 more sources

Visible‐Light Sensitized Isomerization in the Lipid Bilayer Enables Activation of a Transmembrane Transporter

Angewandte Chemie, EarlyView.
A stiff‐stilbene‐based transmembrane anion transporter is isomerized by energy transfer from a ruthenium tris(bipyridyl) photosensitizer in the lipid bilayer. This sensitized isomerization allows activation of chloride transport using visible instead of UV light, without the need to chemically modify the stiff‐stilbene photoswitch.
Julia Villalva, Abhishek Mondal, Willem Marulanda, Jasper E. Bos, Sylvestre Bonnet, Anjali Pandit, Sander J. Wezenberg   +6 more
wiley   +2 more sources

Strategies Toward Accessing Enantioenriched (Hetero)Benzo‐Fused 5‐ and 6‐ Membered Rings via Intermolecular Carbometalation

Angewandte Chemie, EarlyView.
The use of transition‐metal catalysts and design of chiral ligands have allowed chemists to access highly functionalized benzofused 5‐ and 6‐ membered rings in high yield and enantioselectivity. A common strategy used relies on an intermolecular carbometalation across alkynes and olefins, usually followed by a subsequent intramolecular carbometalation.
Clara Jans, Armaan Grewal, Xavier Abel‐Snape, Mark Lautens   +3 more
wiley   +2 more sources