86988-50-3Relevant academic research and scientific papers
Organocatalytic Aerobic Oxidation of α-Fluoroalkyl Alcohols to Fluoroalkyl Ketones at Room Temperature
Kadoh, Yoichi,Tashiro, Masayuki,Oisaki, Kounosuke,Kanai, Motomu
, p. 2193 - 2198 (2015/07/27)
The organocatalytic aerobic oxidation of electron-deficient α-fluoroalkyl alcohols at room temperature is described. The resulting fluoroalkyl ketones are versatile synthetic intermediates for a variety of fluorine-containing molecules. This otherwise difficult transformation has now been accomplished by the reaction of α-fluoroalkyl alcohols with N-oxyl radicals, catalytically generated from 9-azabicyclo[3.3.1]nonan-3-one N-oxyl/nitrogen oxide (keto-ABNO/NOx) and oxygen in acetic acid (AcOH), affording the corresponding fluoroalkyl ketones in high yield. This operationally simple reaction can be performed under mild conditions, and was applied to a wide range of alcohols (20 examples), thus demonstrating a high functional group tolerance. Moreover, a modified one-pot protocol based on this method was able to convert an aldehyde to a trifluoromethyl ketone on a gram scale.
Oxidation of α-trifluoromethyl alcohols using a recyclable oxoammonium salt
Kelly, Christopher B.,Mercadante, Michael A.,Hamlin, Trevor A.,Fletcher, Madison H.,Leadbeater, Nicholas E.
, p. 8131 - 8141 (2013/01/15)
A simple, mild method for the oxidation of α-trifluoromethyl alcohols to trifluoromethyl ketones (TFMKs) using the oxoammonium salt 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1) is described. Under basic conditions, oxidation proceeds rapidly and affords good to excellent yields of TFMKs, without concomitant formation of the hydrate. The byproduct of the oxidation, 4-acetylamino-2,2,6,6-tetramethyl-1- piperidinyloxy (1c), is easily recovered and can be conveniently reoxidized to regenerate the oxoammonium salt.
4-(1-Azi-2,2,2-trifluoroethyl)benzoic Acid, a Highly Photolabile Carbene Generating Label Readily Fixable to Biochemical Agents
Nassal, Michael
, p. 1510 - 1523 (2007/10/02)
The title compound is synthesized starting from either 4-bromobenzyl tert butyldimethylsilyl ether (5b) or 4-bromobenzyl tert-butyl ether (5c) or - most simply - from 4-bromotoluene (5a).In the first step Br was replaced by Li using n-butyllithium, then the organometallic compounds were converted into the respective trifluoroacetophenones 6a - c with N-trifluoroacetylpiperidine.The azi moiety (diazirine) was prepared from the oximes 7a - c via O-tosyloximes 8a - c plus ammonia yielding the diaziridines 9a - c and oxidation of the latter with Ag2O.Oxidation by permanganate - of the ethers after acidic cleavage - yields the title compound 12.On irradation (λ > 300 nm) 12 by elimination of N2 with a half-life period of 22 s generates the corresponding carbene.At the same time from 12 with ca. 20percent the yellow isomeric 4-(1-diazo-2,2,2-trifluoroethyl)benzoic acid (20) is formed which is photolyzed generating the same carbene as 12.The synthesis of 20 is described starting from 4-bromobenzaldehyde. - The diazirine 12 as its N-hydroxysuccinimide ester 13, or using other methods of amide synthesis, can readily be coupled to amino functions of biochemically interesting agents thus forming photoaffinity labels.
REGIOSPECIFIC SYNTHESIS OF AROMATIC COMPOUNDS VIA ORGANOMETALLIC INTERMEDIATES. I. para-SUBSTITUTED BENZENES
Chen, Loomis S.,Chen, Grace J.,Tamborski, Christ
, p. 139 - 148 (2007/10/02)
Para-substituted benzene compounds, p-XC6H4X' (X = CF3C(O) and X' = CH3, CO2H, C(O)CF3, C(O)CH3, C(O)H and SH) have been prepared via sequential metal-halogen exchange reactions between p-BrC6H4Br and n-C4H9Li and the appropriate electrophiles.Low reaction temperature is critical to stabilization of the various intermediates.The CF3 group has a pronounced effect on providing stability to the lithium hemiketal intermediates.
