700-76-5Relevant articles and documents
Direct Access to Chiral β-Fluoroamines with Quaternary Stereogenic Center through Cooperative Cation-Binding Catalysis
Vaithiyanathan, Venkataramasubramanian,Kim, Mun Jong,Liu, Yidong,Yan, Hailong,Song, Choong Eui
, p. 1268 - 1272 (2017)
A direct route to chiral β-fluoroamines with tetrasubstituted C?F centers through the organocatalytic Mannich reaction of α-fluoro cyclic ketones and α-amidosulfones by using a chiral oligoethylene glycol as a cation-binding catalyst and KF as a base is reported. For most substrates, nearly perfect enantioselectivities were achieved even at very high temperatures (>80 °C). The salient features of this process include a) a transition-metal-free and operationally simple procedure, b) direct use of α-amidosulfones as bench-stable precursors of sensitive imines, c) direct enolization of racemic α-fluoro cyclic ketones, and d) excellent stereoselectivity up to 99 % enantiomeric excess and >20:1 diastereoselectivity (anti/syn). Thus, this protocol is easily scalable and provides a new approach for the synthesis of biologically relevant products with tetrasubstituted C?F centers. Furthermore, this protocol was also successfully extended to generate C?Cl and C?Br quaternary stereogenic centers.
Method for synthesizing alpha-fluorinated ketone through hydrazone aliphatic chain monoketone
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Paragraph 0086-0088, (2021/02/06)
The invention belongs to the technical field of organic synthesis, and provides a method for synthesizing alpha-ketone fluoride through hydrazone aliphatic chain monoketone, which comprises the following steps of: reacting aliphatic chain monoketone with hydrazine hydrate to obtain hydrazone, and reacting hydrazone with a compound represented by formula 2 under a heating condition to complete hydrazone defluorination. The fluorinated product is widely applied to medicines, the reaction conditions are mild, and the process is simple.
Flow electrochemistry: a safe tool for fluorine chemistry
Rennigholtz, Tim,Winterson, Bethan,Wirth, Thomas
, p. 9053 - 9059 (2021/07/12)
The heightened activity of compounds containing fluorine, especially in the field of pharmaceuticals, provides major impetus for the development of new fluorination procedures. A scalable, versatile, and safe electrochemical fluorination protocol is conferred. The strategy proceeds through a transient (difluoroiodo)arene, generated by anodic oxidation of an iodoarene mediator. Even the isolation of iodine(iii) difluorides was facile since electrolysis was performed in the absence of other reagents. A broad range of hypervalent iodine mediated reactions were achieved in high yields by coupling the electrolysis step with downstream reactions in flow, surpassing limitations of batch chemistry. (Difluoroiodo)arenes are toxic and suffer from chemical instability, so the uninterrupted generation and immediate use in flow is highly advantageous. High flow rates facilitated productivities of up to 834?mg h?1with vastly reduced reaction times. Integration into a fully automated machine and in-line quenching was key in reducing the hazards surrounding the use of hydrofluoric acid.