57455-06-8Relevant articles and documents
Enantioselective Intermolecular C-H Amination Directed by a Chiral Cation
Fanourakis, Alexander,Paterson, Kieran J.,Phipps, Robert J.,Williams, Benjamin D.
supporting information, p. 10070 - 10076 (2021/07/21)
The enantioselective amination of C(sp3)-H bonds is a powerful synthetic transformation yet highly challenging to achieve in an intermolecular sense. We have developed a family of anionic variants of the best-in-class catalyst for Rh-catalyzed C-H amination, Rh2(esp)2, with which we have associated chiral cations derived from quaternized cinchona alkaloids. These ion-paired catalysts enable high levels of enantioselectivity to be achieved in the benzylic C-H amination of substrates bearing pendant hydroxyl groups. Additionally, the quinoline of the chiral cation appears to engage in axial ligation to the rhodium complex, providing improved yields of product versus Rh2(esp)2 and highlighting the dual role that the cation is playing. These results underline the potential of using chiral cations to control enantioselectivity in challenging transition-metal-catalyzed transformations.
Novel bi-halogenated acetylated heterocyclic pyrethroid and preparation and application methods thereof
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Paragraph 0027; 0028, (2019/05/02)
The invention relates to the technical field of medicines, particularly to a novel bi-halogenated acetylated heterocyclic pyrethroid and preparation and application methods thereof. The novel bi-halogenated acetylated heterocyclic pyrethroid has a chemical structural formula shown as the formula I. The preparation method of the novel bi-halogenated acetylated heterocyclic pyrethroid comprises thefollowing steps of, firstly, reducing methyl m-iodobenzoate with LiBH4 to obtain m-iodobenzyl alcohol; secondly, mixing dimethylcyclopropane carboxylic acid, oxalyl chloride, N, N-dimethyl formamide and the m-iodobenzyl alcohol for mixed reaction to obtain DCA-O (dimethylcyclopropane carboxylate) compounds; thirdly, through Suzuki coupling, subjecting the DCA-O prepared in the second step, PdCl2(dppf), K3PO4 and boric acid to reaction to obtain the novel bi-halogenated acetylated heterocyclic pyrethroid. The novel bi-halogenated acetylated heterocyclic pyrethroid is applied as a mosquito growth inhibiting pesticide. The novel bi-halogenated acetylated heterocyclic pyrethroid and the preparation and application methods thereof solve the technical problem that pyrethroid pesticides in the prior art cannot integrate mosquito killing activity and pesticide resistance.
Ortho-stabilized 18F-azido click agents and their application in PET imaging with single-stranded DNA aptamers
Wang, Lu,Jacobson, Orit,Avdic, Din,Rotstein, Benjamin H.,Weiss, Ido D.,Collier, Lee,Chen, Xiaoyuan,Vasdev, Neil,Liang, Steven H.
supporting information, p. 12777 - 12781 (2015/10/28)
Azido 18F-arenes are important and versatile building blocks for the radiolabeling of biomolecules via Huisgen cycloaddition ("click chemistry") for positron emission tomography (PET). However, routine access to such clickable agents is challenged by inefficient and/or poorly defined multistep radiochemical approaches. A high-yielding direct radiofluorination for azido 18F-arenes was achieved through the development of an ortho-oxygen-stabilized iodonium derivative (OID). This OID strategy addresses an unmet need for a reliable azido 18F-arene clickable agent for bioconjugation reactions. A ssDNA aptamer was radiolabeled with this agent and visualized in a xenograft mouse model of human colon cancer by PET, which demonstrates that this OID approach is a convenient and highly efficient way of labeling and tracking biomolecules. Markedly apt: A high-yielding direct radiofluorination strategy via ortho-oxygen-substituted iodonium derivatives is described. A ssDNA aptamer (sgc8), labelled with the resulting 18F azido agent through click chemistry, was used for PET imaging and provides the first example for the noninvasive in vivo PET imaging of protein tyrosine kinase 7 (PTK-7).
