Photoalkylation/-arylation of ortho-Diketones with Unactivated Organic Halides.

A new method for conducting a reductive alkylation/arylation of 1,2-diketones using visible light and unactivated organic halides is presented in this article. This technique does not require a photocatalyst and employs Et3N, a tertiary amine, as a promoter. This amine aids in generating a ketyl radical and an α-aminoalkyl radical, which engages in a C-X bond activation via a halogen atom transfer process (XAT). This approach's success hinges on utilizing Et3N as the promoter. This article's mild and straightforward protocol allows for significantly expanding organic halide substrates, including primary, secondary, and aromatic organic halides and various functional groups.

[1]  Jiabin Shen,et al.  α-Amino Radical-Mediated Difunctionalization of Alkenes with Polyhaloalkanes and N-Heteroarenes. , 2023, Organic letters.

[2]  Yubing Huang,et al.  Cathodic Carbonyl Alkylation of Aryl Ketones or Aldehydes with Unactivated Alkyl Halides. , 2022, Organic letters.

[3]  J. Kaur,et al.  α‐Amino Radical Halogen Atom Transfer Agents for Metallaphotoredox‐Catalyzed Cross‐Electrophile Couplings of Distinct Organic Halides , 2022, ChemSusChem.

[4]  D. Leonori,et al.  Applications of Halogen-Atom Transfer (XAT) for the Generation of Carbon Radicals in Synthetic Photochemistry and Photocatalysis. , 2021, Chemical reviews.

[5]  D. MacMillan,et al.  Metallaphotoredox: The Merger of Photoredox and Transition Metal Catalysis. , 2021, Chemical reviews.

[6]  David A. Nicewicz,et al.  Photoredox-Catalyzed C-H Functionalization Reactions. , 2021, Chemical reviews.

[7]  Yuxiu Liu,et al.  Visible-Light-Mediated C-I Difluoroallylation with an α-Aminoalkyl Radical as a Mediator. , 2021, Organic letters.

[8]  D. Leonori,et al.  Merging Halogen-Atom Transfer (XAT) and Cobalt Catalysis to Override E2-Selectivity in the Elimination of Alkyl Halides: A Mild Route toward contra-Thermodynamic Olefins. , 2021, Journal of the American Chemical Society.

[9]  L. Overman,et al.  Strategic Use of Visible-Light Photoredox Catalysis in Natural Product Synthesis. , 2021, Chemical reviews.

[10]  James J. Douglas,et al.  Copper-catalysed amination of alkyl iodides enabled by halogen-atom transfer , 2021, Nature Catalysis.

[11]  M. Giedyk,et al.  Photocatalytic strategies for the activation of organic chlorides , 2020, Nature Catalysis.

[12]  M. Zanini,et al.  Aminoalkyl radicals as halogen-atom transfer agents for activation of alkyl and aryl halides , 2020, Science.

[13]  Graham C. Haug,et al.  Visible Light-Induced Borylation of C-O, C-N, and C-X Bonds. , 2020, Journal of the American Chemical Society.

[14]  Xinhao Zhang,et al.  Generation of Halomethyl Radicals by Halogen Atom Abstraction and Their Addition Reactions with Alkenes. , 2019, Journal of the American Chemical Society.

[15]  J. Yu,et al.  Visible-Light-Induced Atom Transfer Radical Addition and Cyclization of Perfluoroalkyl Halides with 1,n-Enynes , 2019, ACS Sustainable Chemistry & Engineering.

[16]  Hongjian Song,et al.  Visible-Light Photocatalysis of the Ketyl Radical Coupling Reaction. , 2018, Chemistry.

[17]  H. Rao,et al.  Studies towards iodine-catalyzed dehydrative-cycloisomerization of pent-4-yne-1,2-diols to di- and tri-substituted furans , 2018, Tetrahedron.

[18]  Y. Landais,et al.  Thirty Years of (TMS)3SiH: A Milestone in Radical-Based Synthetic Chemistry. , 2018, Chemical reviews.

[19]  Ming‐Yu Ngai,et al.  β-Selective Reductive Coupling of Alkenylpyridines with Aldehydes and Imines via Synergistic Lewis Acid/Photoredox Catalysis. , 2017, Journal of the American Chemical Society.

[20]  Yiyun Chen,et al.  Polarity-Reversed Allylations of Aldehydes, Ketones, and Imines Enabled by Hantzsch Ester in Photoredox Catalysis. , 2016, Angewandte Chemie.

[21]  H. Rao,et al.  The Voight reaction on tertiary α-hydroxy ketones , 2015 .

[22]  Jeongae Choi,et al.  Synthesis of Tribenzotropone by Ring Expansion of Phenanthrene-9,10-dione , 2015, Synthesis.

[23]  M. Rueping,et al.  Photoredox-Catalyzed Reductive Coupling of Aldehydes, Ketones, and Imines with Visible Light. , 2015, Angewandte Chemie.

[24]  A. Takuwa,et al.  Photo-allylation and photo-benzylation of carbonyl compounds using organotrifluoroborate reagents , 2009 .

[25]  W. Hagmann,et al.  The many roles for fluorine in medicinal chemistry. , 2008, Journal of medicinal chemistry.

[26]  Dae Won Cho,et al.  Photoaddition reactions of 1,2-diketones with silyl ketene acetals. formation of beta-hydroxy-gamma-ketoesters. , 2008, The Journal of organic chemistry.

[27]  V. Kouznetsov,et al.  Recent Developments in Three-Component Grignard-Barbier-Type Reactions , 2008 .

[28]  F. Diederich,et al.  Fluorine in Pharmaceuticals: Looking Beyond Intuition , 2007, Science.

[29]  A. Suzuki,et al.  Remarkable enhancement of photo-allylation of aromatic carbonyl compounds with a hypervalent allylsilicon reagent by donor molecules , 2007 .

[30]  Zhiyong Wang,et al.  High regio- and stereoselective Barbier reaction of carbonyl compounds mediated by NaBF4/Zn (Sn) in water , 2003 .

[31]  M. Matsuura,et al.  Contrasting Regiochemistry in Thermal and Photochemical Allylstannations of 1,2-Naphthoquinone , 1999 .

[32]  C. Chatgilialoglu Organosilanes as radical-based reducing agents in synthesis , 1992 .

[33]  W. Neumann Tri-n-butyltin Hydride as Reagent in Organic Synthesis , 1988 .

[34]  Y. Naruta,et al.  Photochemical Reaction of 9,10-Phenanthrenequinone with Hydrogen Donors. Behavior of Radicals in Solution as Studied by CIDNP , 1976 .

[35]  K. Takagi,et al.  Photochemical reductions of unsymmetrical benzils , 1972 .

[36]  K. Park,et al.  Photochemical Reductions of Benzil and Benzoin in the Presence of Triethylamine and TiO2 Photocatalyst , 2002 .

[37]  T. L. Brown,et al.  Rates of halogen atom transfer to manganese carbonyl radicals , 1985 .