365-00-4Relevant articles and documents
Enolization rates control mono-: Versus di-fluorination of 1,3-dicarbonyl derivatives
Rozatian, Neshat,Beeby, Andrew,Ashworth, Ian W.,Sandford, Graham,Hodgson, David R.W.
, p. 10318 - 10330 (2019/11/20)
Fluorine-containing 1,3-dicarbonyl derivatives are essential building blocks for drug discovery and manufacture. To understand the factors that determine selectivity between mono- and di-fluorination of 1,3-dicarbonyl systems, we have performed kinetic studies of keto-enol tautomerism and fluorination processes. Photoketonization of 1,3-diaryl-1,3-dicarbonyl derivatives and their 2-fluoro analogues is coupled with relaxation kinetics to determine enolization rates. Reaction additives such as water accelerate enolization processes, especially of 2-fluoro-1,3-dicarbonyl systems. Kinetic studies of enol fluorination with Selectfluor and NFSI reveal the quantitative effects of 2-fluorination upon enol nucleophilicity towards reagents of markedly different electrophilicity. Our findings have important implications for the synthesis of α,α-difluoroketonic compounds, providing valuable quantitative information to aid in the design of fluorination and difluorination reactions.
Translating solid state organic synthesis from a mixer mill to a continuous twin screw extruder
Cao, Qun,Howard, Joseph L.,Crawford, Deborah E.,James, Stuart L.,Browne, Duncan L.
supporting information, p. 4443 - 4447 (2018/10/17)
A study on the translation of a solid-state synthetic reaction from a mechanochemical mixer-mill to a continuous twin-screw extruder is discussed herein. The study highlights some considerations to be made and parameters to be tested in the context of a model fluorination reaction, which is the first organic fluorination to be attempted using extrusion. Upon optimization, which features the first use of grinding auxiliary solids to enable effective synthetic extrusion, the difluorination reaction was successfully translated to the extruder, leading to a 100-fold improvement in Space Time Yield (STY); 29 kg m-3 day-1 in a mixer mill to 3395 kg m-3 day-1 in a twin screw extruder.
SelectfluorTMon a PolyHIPE Material as Regenerative and Reusable Polymer-Supported Electrophilic Fluorinating Agent
Kawada, Kosuke,Okano, Koji,Iskra, Jernej,Krajnc, Peter,Cahard, Dominique
supporting information, p. 584 - 589 (2017/02/23)
The first recyclable polymer-supported electrophilic fluorinating agent was prepared by reaction of molecular fluorine with the triethylenediamine motif that is grafted onto a poly(4-vinylbenzyl chloride-co-divinylbenzene) polyHIPE material. The resulting
