1556-09-8Relevant articles and documents
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Roberts,D.D.,Traynham,J.G.
, p. 3177 - 3182 (1967)
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Preparation method of alkane brominated material
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Paragraph 0046-0047, (2018/09/08)
The invention relates to a preparation method of an alkane brominated material. The preparation method comprises the following steps: adding alkane, a bromine-containing compound or elemental bromine,a catalyst and acid into a solvent; adding the solvent into a light-transmission reaction container under air or oxygen atmosphere; sealing; performing stirring reaction under constant pressure and light illumination conditions; then analyzing a nuclear magnetic yield, and performing extraction, drying, filtration, distillation under reduced pressure and column separation to obtain the alkane brominated material. Compared with the prior art, the preparation method disclosed by the invention has the advantages that by using low-cost and safe bromic salt as a bromine source, the air as an oxidizing agent and a nitrogen-containing reagent as the catalyst, reaction is carried out under the conditions of constant temperature and constant pressure, so that energy conservation and economy are realized, and the preparation method is convenient and safe to operate and is environmentally friendly.
A General Strategy for Aliphatic C-H Functionalization Enabled by Organic Photoredox Catalysis
Margrey, Kaila A.,Czaplyski, William L.,Nicewicz, David A.,Alexanian, Erik J.
supporting information, p. 4213 - 4217 (2018/04/05)
Synthetic transformations that functionalize unactivated aliphatic C-H bonds in an intermolecular fashion offer unique strategies for the synthesis and late-stage derivatization of complex molecules. Herein we report a general approach to the intermolecular functionalization of aliphatic C-H bonds using an acridinium photoredox catalyst and phosphate salt under blue LED irradiation. This strategy encompasses a range of valuable C-H transformations, including the direct conversions of a C-H bond to C-N, C-F, C-Br, C-Cl, C-S, and C-C bonds, in all cases using the alkane substrate as the limiting reagent. Detailed mechanistic studies are consistent with the intermediacy of a putative oxygen-centered radical as the hydrogen atom-abstracting species in these processes.
Selective C-H halogenation over hydroxylation by non-heme iron(iv)-oxo
Rana, Sujoy,Biswas, Jyoti Prasad,Sen, Asmita,Clémancey, Martin,Blondin, Geneviève,Latour, Jean-Marc,Rajaraman, Gopalan,Maiti, Debabrata
, p. 7843 - 7858 (2018/10/31)
Non-heme iron based halogenase enzymes promote selective halogenation of the sp3-C-H bond through iron(iv)-oxo-halide active species. During halogenation, competitive hydroxylation can be prevented completely in enzymatic systems. However, synthetic iron(iv)-oxo-halide intermediates often result in a mixture of halogenation and hydroxylation products. In this report, we have developed a new synthetic strategy by employing non-heme iron based complexes for selective sp3-C-H halogenation by overriding hydroxylation. A room temperature stable, iron(iv)-oxo complex, [Fe(2PyN2Q)(O)]2+ was directed for hydrogen atom abstraction (HAA) from aliphatic substrates and the iron(ii)-halide [FeII(2PyN2Q)(X)]+ (X, halogen) was exploited in conjunction to deliver the halogen atom to the ensuing carbon centered radical. Despite iron(iv)-oxo being an effective promoter of hydroxylation of aliphatic substrates, the perfect interplay of HAA and halogen atom transfer in this work leads to the halogenation product selectively by diverting the hydroxylation pathway. Experimental studies outline the mechanistic details of the iron(iv)-oxo mediated halogenation reactions. A kinetic isotope study between PhCH3 and C6D5CD3 showed a value of 13.5 that supports the initial HAA step as the RDS during halogenation. Successful implementation of this new strategy led to the establishment of a functional mimic of non-heme halogenase enzymes with an excellent selectivity for halogenation over hydroxylation. Detailed theoretical studies based on density functional methods reveal how the small difference in the ligand design leads to a large difference in the electronic structure of the [Fe(2PyN2Q)(O)]2+ species. Both experimental and computational studies suggest that the halide rebound process of the cage escaped radical with iron(iii)-halide is energetically favorable compared to iron(iii)-hydroxide and it brings in selective formation of halogenation products over hydroxylation.
