1429428-05-6Relevant articles and documents
C(sp3)?C(sp3) Cross-Coupling of Alkyl Bromides and Ethers Mediated by Metal and Visible Light Photoredox Catalysis
Santos, Marilia S.,Corrêa, Arlene G.,Paix?o, Márcio W.,K?nig, Burkhard
, p. 2367 - 2372 (2020)
We report a C(sp3)?C(sp3) cross-coupling of alkyl bromides and alkyl chlorides with ethers by dual photoredox-nickel catalysis. The catalytic system comprises of the organic photocatalyst 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4-CzIPN) and bench stable nickel (II) acetylacetonate in the presence of visible-light, providing the coupling products in up to 92% yield. Preliminary mechanistic studies suggest two catalytic cycles, as well as the photogeneration of bromine or chlorine radicals from halide atoms that are present in the structures of the coupling partners. The halide radical mediates the hydrogen atom transfer event, avoiding the need of an additional HAT catalyst. (Figure presented.).
Gold(I)/Gold(III) Catalysis that Merges Oxidative Addition and π-Alkene Activation
Amgoune, Abderrahmane,Bourissou, Didier,Rigoulet, Mathilde,Thillaye du Boullay, Olivier
supporting information, p. 16625 - 16630 (2020/07/24)
Heteroarylation of alkenes with aryl iodides was efficiently achieved with a (MeDalphos)AuCl complex through AuI/AuIII catalysis. The possibility to combine oxidative addition of aryl iodides and π-activation of alkenes at gold is demonstrated for the first time. The reaction is robust and general (>30 examples including internal alkenes, 5-, 6-, and 7-membered rings). It is regioselective and leads exclusively to trans addition products. The (P,N) gold complex is most efficient with electron-rich aryl substrates, which are troublesome with alternative photoredox/oxidative approaches. In addition, it provides a very unusual switch in regioselectivity from 5-exo to 6-endo cyclization between the Z and E isomers of internal alkenols.
Gold Redox Catalysis through Base-Initiated Diazonium Decomposition toward Alkene, Alkyne, and Allene Activation
Dong, Boliang,Peng, Haihui,Motika, Stephen E.,Shi, Xiaodong
supporting information, p. 11093 - 11099 (2017/08/22)
The discovery of photoassisted diazonium activation toward gold(I) oxidation greatly extended the scope of gold redox catalysis by avoiding the use of a strong oxidant. Some practical issues that limit the application of this new type of chemistry are the relative low efficiency (long reaction time and low conversion) and the strict reaction condition control that is necessary (degassing and inert reaction environment). Herein, an alternative photofree condition has been developed through Lewis base induced diazonium activation. With this method, an unreactive AuI catalyst was used in combination with Na2CO3 and diazonium salts to produce a AuIII intermediate. The efficient activation of various substrates, including alkyne, alkene and allene was achieved, followed by rapid AuIII reductive elimination, which yielded the C?C coupling products with good to excellent yields. Relative to the previously reported photoactivation method, our approach offered greater efficiency and versatility through faster reaction rates and broader reaction scope. Challenging substrates such as electron rich/neutral allenes, which could not be activated under the photoinitiation conditions (5 % yield), could be activated to subsequently yield the desired coupling products in good to excellent yield.
Combining gold and photoredox catalysis: Visible light-mediated oxy-and aminoarylation of alkenes
Sahoo, Basudev,Hopkinson, Matthew N.,Glorius, Frank
supporting information, p. 5505 - 5508 (2013/05/23)
A room-temperature intramolecular oxy-and aminoarylation of alkenes with aryldiazonium salts has been developed using a novel gold and photoredox dual-catalytic system. The compatibility of these two catalytic modes has been established for the first time and demonstrates the potential of this system as a method to expand the scope of nucleophilic addition reactions to carbon-carbon multiple bonds.
