Hydroheteroarylation of Unactivated Alkenes Using <i>N</i>-Methoxyheteroarenium Salts
作者:Xiaoshen Ma、Hester Dang、John A. Rose、Paul Rablen、Seth B. Herzon
DOI:10.1021/jacs.7b02388
日期:2017.4.26
reductive coupling of unactivated alkenes with N-methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts under hydrogen atom transfer (HAT) conditions, and an expanded scope for the coupling of alkenes with N-methoxy pyridinium salts. N-Methoxy pyridazinium, imidazolium, quinolinium, and isoquinolinium salts are accessible in 1-2 steps from the commercial arenes or arene N-oxides (25-99%)
α-Heteroarylation of Thioethers via Photoredox and Weak Brønsted Base Catalysis
作者:Edwin Alfonzo、Sudhir M. Hande
DOI:10.1021/acs.orglett.1c02151
日期:2021.8.6
thioethers to α-thio alkyl radicals and their addition to N-methoxyheteroarenium salts for the redox-neutral synthesis of α-heteroaromatic thioethers. Studies are consistent with a two-step activation mechanism, where oxidation of thioethers to sulfide radical cations by a photoredox catalyst is followed by α-C–H deprotonation by a weak Brønsted base catalyst to afford α-thio alkyl radicals. Further,
Intermolecular Hydropyridylation of Unactivated Alkenes
作者:Xiaoshen Ma、Seth B. Herzon
DOI:10.1021/jacs.6b05271
日期:2016.7.20
A general method for the hydropyridylation of unactivatedalkenes is described. The transformation connects metal-mediated hydrogen atom transfer to alkenes and Minisci addition reactions. The reaction proceeds under mild conditions with high site-selectivities and allows for the construction of tertiary and quaternary centers from simple alkene starting materials.
has the potential to facilitate many important organic transformations but proves to have few relevant reported reactions. Herein, we explore the synergistic role of catalytic systems driven by graphene oxide and visible light that form nucleophilic alkoxyl radical intermediates, which enable an anti-Markovnikov addition exclusively to the terminalalkenes, and then the produced benzyl radicals are subsequently
Photochemical C–H Silylation and Hydroxymethylation of Pyridines and Related Structures: Synthetic Scope and Mechanisms
作者:Fatima Rammal、Di Gao、Sondes Boujnah、Aqeel A. Hussein、Jacques Lalevée、Annie-Claude Gaumont、Fabrice Morlet-Savary、Sami Lakhdar
DOI:10.1021/acscatal.0c03726
日期:2020.11.20
Considering the synthetic relevance of heteroarenes in various areas ranging from organic synthesis to medicinal chemistry, developing practically simple methodologies to access functionalized heteroarenes is of a significant value. Described herein is an efficient approach for C–H silylation and hydroxymethylation of pyridines and related heterocycles by the combination of silanes or methanol with readily