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
-
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.
Rapid and efficient copper-catalyzed finkelstein reaction of (hetero)aromatics under continuous-flow conditions
Chen, Mao,Ichikawa, Saki,Buchwald, Stephen L.
supporting information, p. 263 - 266 (2015/02/05)
A general, rapid, and efficient method for the copper-catalyzed Finkelstein reaction of (hetero)aromatics has been developed using continuous flow to generate a variety of aryl iodides. The described method can tolerate a broad spectrum of functional groups, including N-H and O-H groups. Additionally, in lieu of isolation, the aryl iodide solutions were used in two distinct multistep continuous-flow processes (amidation and Mg-I exchange/nucleophilic addition) to demonstrate the flexibility of this method.
