16632-09-0Relevant articles and documents
Radical Hydroarylation of Functionalized Olefins and Mechanistic Investigation of Photocatalytic Pyridyl Radical Reactions
Seath, Ciaran P.,Vogt, David B.,Xu, Zihao,Boyington, Allyson J.,Jui, Nathan T.
supporting information, p. 15525 - 15534 (2018/11/23)
We report the photoredox alkylation of halopyridines using functionalized alkene and alkyne building blocks. Selective single-electron reduction of the halogenated pyridines provides the corresponding heteroaryl radicals, which undergo anti-Markovnikov addition to the alkene substrates. The system is shown to be mild and tolerant of a variety of alkene and alkyne subtypes. A combination of computational and experimental studies support a mechanism involving proton-coupled electron transfer followed by medium-dependent alkene addition and rapid hydrogen atom transfer mediated by a polarity-reversal catalyst.
C-H FLUORINATION OF HETEROCYCLES WITH SILVER (II) FLUORIDE
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Paragraph 00165, (2015/02/19)
The present invention provides compositions and methods for the selective C-H fluorination of nitrogen-containing heteroarenes with AgF2, which has previously been considered too reactive for practical, selective C-H fluorination. Fluorinated heteroarenes are prevalent in numerous pharmaceuticals, agrochemicals and materials. However, the reactions used to introduce fluorine into these molecules require pre-functionalized substrates or the use of F2 gas. The present invention provides a mild and general method for the C-H fluorination of nitrogen-containing heteroarene compounds to 2-fluoro-heteroarenes with commercially available AgF2. In various embodiments, these reactions occur at ambient temperature within one hour and occur with exclusive selectivity for fluorination at the 2-position. Exemplary reaction conditions are effective for fluorinating diazine heteroarenes to form a single fluorinated isomer.
Synthesis and late-stage functionalization of complex molecules through C-H fluorination and nucleophilic aromatic substitution
Fier, Patrick S.,Hartwig, John F.
supporting information, p. 10139 - 10147 (2014/08/05)
We report the late-stage functionalization of multisubstituted pyridines and diazines at the position α to nitrogen. By this process, a series of functional groups and substituents bound to the ring through nitrogen, oxygen, sulfur, or carbon are installed. This functionalization is accomplished by a combination of fluorination and nucleophilic aromatic substitution of the installed fluoride. A diverse array of functionalities can be installed because of the mild reaction conditions revealed for nucleophilic aromatic substitutions (SNAr) of the 2-fluoroheteroarenes. An evaluation of the rates for substitution versus the rates for competitive processes provides a framework for planning this functionalization sequence. This process is illustrated by the modification of a series of medicinally important compounds, as well as the increase in efficiency of synthesis of several existing pharmaceuticals.
