17777-31-0Relevant articles and documents
A General Organocatalytic System for Electron Donor-Acceptor Complex Photoactivation and Its Use in Radical Processes
De Pedro Beato, Eduardo,Melchiorre, Paolo,Spinnato, Davide,Zhou, Wei
supporting information, p. 12304 - 12314 (2021/08/20)
We report herein a modular class of organic catalysts that, acting as donors, can readily form photoactive electron donor-acceptor (EDA) complexes with a variety of radical precursors. Excitation with visible light generates open-shell intermediates under mild conditions, including nonstabilized carbon radicals and nitrogen-centered radicals. The modular nature of the commercially available xanthogenate and dithiocarbamate anion organocatalysts offers a versatile EDA complex catalytic platform for developing mechanistically distinct radical reactions, encompassing redox-neutral and net-reductive processes. Mechanistic investigations, by means of quantum yield determination, established that a closed catalytic cycle is operational for all of the developed radical processes, highlighting the ability of the organic catalysts to turn over and iteratively drive every catalytic cycle. We also demonstrate how the catalysts' stability and the method's high functional group tolerance could be advantageous for the direct radical functionalization of abundant functional groups, including aliphatic carboxylic acids and amines, and for applications in the late-stage elaboration of biorelevant compounds and enantioselective radical catalysis.
Nickel-Catalyzed Migratory Hydrocyanation of Internal Alkenes: Unexpected Diastereomeric-Ligand-Controlled Regiodivergence
Gao, Jihui,Jiao, Mingdong,Ni, Jie,Yu, Rongrong,Cheng, Gui-Juan,Fang, Xianjie
supporting information, p. 1883 - 1890 (2020/12/01)
A regiodivergent nickel-catalyzed hydrocyanation of a broad range of internal alkenes involving a chain-walking process is reported. When appropriate diastereomeric biaryl diphosphite ligands are applied, the same starting materials can be converted to either linear or branched nitriles with good yields and high regioselectivities. DFT calculations suggested that the catalyst architecture determines the regioselectivity by modulating electronic and steric interactions. In addition, moderate enantioselectivities were observed when branched nitriles were produced.
Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation of Alkenes and Alkynes Using 1-Methylcyclohexa-2,5-diene-1-carbonitrile
Bhunia, Anup,Bergander, Klaus,Studer, Armido
supporting information, p. 16353 - 16359 (2018/11/25)
Catalytic transfer hydrocyanation represents a clean and safe alternative to hydrocyanation processes using toxic HCN gas. Such reactions provide access to pharmaceutically important nitrile derivatives starting with alkenes and alkynes. Herein, an efficient and practical cooperative palladium/Lewis acid-catalyzed transfer hydrocyanation of alkenes and alkynes is presented using 1-methylcyclohexa-2,5-diene-1-carbonitrile as a benign and readily available HCN source. A large set of nitrile derivatives (>50 examples) are prepared from both aliphatic and aromatic alkenes with good to excellent anti-Markovnikov selectivity. A range of aliphatic alkenes engage in selective hydrocyanation to provide the corresponding nitriles. The introduced method is useful for chain walking hydrocyanation of internal alkenes to afford terminal nitriles in good regioselectivities. This protocol is also applicable to late-stage modification of bioactive molecules.
