Additions of Aldehyde-Derived Radicals and Nucleophilic <i>N</i>-Alkylindoles to Styrenes by Photoredox Catalysis
作者:Marcel Lux、Martin Klussmann
DOI:10.1021/acs.orglett.0c01182
日期:2020.5.1
addition of acyl radicals and N-alkylindole nucleophiles to styrenes was established, as well as some additional radical-nucleophile combinations. Both aryl and aliphatic aldehydes give reasonable yields. The reaction proceeds best for α-substituted styrenes, effectively creating a quaternary all-carbon center. Some iridium-based photoredox systems are catalytically active; furthermore, a base is needed
Photocatalytic Reductive Radical‐Polar Crossover for a Base‐Free Corey–Seebach Reaction
作者:Karsten Donabauer、Kathiravan Murugesan、Urša Rozman、Stefano Crespi、Burkhard König
DOI:10.1002/chem.202003000
日期:2020.10.9
abstraction of a hydrogen atom followed by radical reduction. The generated nucleophilic intermediate is then capable of adding to carbonyl electrophiles. The obtained dithiane can be easily converted to the valuable α‐hydroxy carbonyl in a subsequent step. The proposed reaction mechanism is supported by emission quenching, radical–radical homocoupling and deuterium labeling studies as well as by calculated
Photocatalytic Hydroaminoalkylation of Styrenes with Unprotected Primary Alkylamines
作者:Hannah E. Askey、James D. Grayson、Joshua D. Tibbetts、Jacob C. Turner-Dore、Jake M. Holmes、Gabriele Kociok-Kohn、Gail L. Wrigley、Alexander J. Cresswell
DOI:10.1021/jacs.1c07401
日期:2021.10.6
moderately electron-rich aryl groups. A broad range of functionalities are tolerated, and the reactions can be run on multigram scale in continuous flow. The method is applied to a concise, protecting-group-free synthesis of the blockbuster drug Fingolimod, as well as a phosphonate mimic of its in vivo active form (by iterative α-C–H functionalization of ethanolamine). The reaction can also be sequenced
Reactivity of Superbasic Carbanions Generated via Reductive Radical‐Polar Crossover in the Context of Photoredox Catalysis
作者:Sascha Grotjahn、Christina Graf、Jan Zelenka、Aryaman Pattanaik、Lea Müller、Roger Jan Kutta、Julia Rehbein、Jana Roithová、Ruth M. Gschwind、Patrick Nuernberger、Burkhard König
DOI:10.1002/anie.202400815
日期:2024.4.24
Photocatalytic reactions with a reductive radical-polar crossover (RRPCO) involve intermediates with carbanionic reactivity. These are best described as free carbanions. Reactions with such carbanions depend on the balance between their nucleophilicity and basicity. Deprotonation of reaction partners and common organic solvents such as acetonitrile, dimethylformamide, and dimethylsulfoxide is the main
Development and Proof of Concept for a Large-Scale Photoredox Additive-Free Minisci Reaction
作者:Mark A. Graham、Gary Noonan、Janette H. Cherryman、James J. Douglas、Miguel Gonzalez、Lucinda V. Jackson、Kevin Leslie、Zhi-qing Liu、David McKinney、Rachel H. Munday、Chris D. Parsons、David T. E. Whittaker、En-xuan Zhang、Jun-wang Zhang