1294481-26-7Relevant academic research and scientific papers
Deuteration of Formyl Groups via a Catalytic Radical H/D Exchange Approach
Zhang, Yueteng,Ji, Peng,Dong, Yue,Wei, Yongyi,Wang, Wei
, p. 2226 - 2230 (2020)
H/D exchange at formyl groups represents the straightforward approach to C-1 deuterated aldehydes. This transformation has been recently realized by transition metal and NHC carbene catalysis. Mechanistically, all of these processes involve an ionic pathway. Herein, we report a distinct photoredox catalytic, visible light mediated neutral radical approach. Selective control of highly reactive acyl radical in the energy barrier surmountable, reversible reaction enables driving the formation of deuterated products when an excess of D2O is employed. The power of the H/D exchange process has been demonstrated for not only aromatic aldehydes but also aliphatic substrates, which have been difficult in transitional metal catalyzed H/D exchange reactions, and for selective late-stage deuterium incorporation into complex structures with uniformly high deuteration level (>90%).
VISIBLE-LIGHT MEDIATED ORGANOPHOTOREDOX CATALYTIC DEUTERATION OF AROMATIC AND ALIPHATIC ALDEHYDES
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Paragraph 0052; 0056; 00103; 00115-00116, (2021/06/22)
Described are methods for preparing a deuterated aldehyde using with a photocatalyst and a hydrogen atom transfer agent in a H2O free solvent comprising D2O and an organic solvent under an inert gas. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions.
Understanding the fate of the oxyallyl cation following Nazarov electrocyclization: Sequential Wagner-Meerwein migrations and the synthesis of spirocyclic cyclopentenones
Huang, Jie,Lebaeuf, David,Frontier, Alison J.
supporting information; experimental part, p. 6307 - 6317 (2011/06/22)
A general reaction sequence is described that involves Nazarov cyclization followed by two sequential Wagner-Meerwein migrations, to afford spirocyclic compounds from divinyl ketones in the presence of 1 equiv of copper(II) complexes. A detailed investigation of this sequence is described including a study of substrate scope and limitations. It was found that after 4π electrocyclization, two different pathways are available to the oxyallyl cation intermediate: elimination of a proton can give the usual Nazarov cycloadduct, or ring contraction can give an alternative tertiary carbocation. After ring contraction, either [1,2]-hydride or carbon migration can occur, depending upon the substitution pattern of the substrate, to furnish spirocyclic products. The rearrangement pathway is favored over the elimination pathway when catalyst loading is high and the copper(II) counterion is noncoordinating. Several ligands were found to be effective for the reaction. Thus, the reaction sequence can be controlled by judicious choice of reaction conditions to allow selective generation of richly functionalized spirocycles. The three steps of the sequence are stereospecific: electrocyclization followed by two [1,2]-suprafacial Wagner-Meerwein shifts, the ring contraction and then a hydride, alkenyl, or aryl shift. The method allows stereospecific installation of adjacent stereocenters or adjacent quaternary centers arrayed around a cyclopentenone ring.
