Nucleophilic introduction of fluorinated alkyl groups into aldehydes and ketones using the corresponding alkyl halide with samarium(II) iodide
作者:Masato Yoshida、Daiki Suzuki、Masahiko Iyoda
DOI:10.1039/a606048j
日期:——
Fluorinated alkyl groups such as PhCF2,
C6F13, CF3CCl2 and
CF2CO2Et are nucleophilically introduced into an
aldehyde or ketone using fluorinated alkyl halides with SmI2;
the reaction proceeds effectively at room temperature to give the
corresponding alcohol. Furthermore, the synthesis of
PhCF2SiMe3,
C6F13SiMe3 and
C6F13SiMe2Pri is achieved by
reaction of the halide with SmI2 in the presence of the silyl
chloride; the resultant fluoroalkylated silyl compounds are used as
reagents for nucleophilic fluoroalkylation.
2-Chloro-3,3,3-trifluoropropene derivatives are also prepared
selectively by the reaction of CF3CCl3 with an
excess of SmI2 in the presence of an aldehyde and
PriOH.
The Difluoromethyl Group as a Masked Nucleophile: A Lewis Acid/Base Approach
作者:Jacob B. Geri、Michael M. Wade Wolfe、Nathaniel K. Szymczak
DOI:10.1021/jacs.8b06093
日期:2018.8.1
that the combination of a Brønsted superbase with a weak Lewisacid enables deprotonation of Ar-CF2H groups and capture of reactive Ar-CF2- fragments. This route provides access to isolable and reactive Ar-CF2- synthons that react with a broad array of electrophiles at room temperature. The methodology is highly general in both electrophile and difluoromethyl (hetero)arene and can be applied directly
Facile Preparation of Fluorine-containing Alkenes, Amides and Alcohols <i>via</i> the Electrophilic Fluorination of Alkenyl Boronic Acids and Trifluoroborates
Reaction of alkenyl boronic acids, or preferably alkenyl trifluoroborates, with one equivalent of SelectfluorTM gives the corresponding alkenyl fluorides. A similar reaction with two equivalents of SelectfluorTM in water or a nitrile solvent gives difluoromethyl-substituted alcohols and amides respectively.
Convenient Synthesis of α,α-Difluorinated Carbonyl Compounds from Alkynes through a Fluoro-deboronation Process
作者:Elena Fernandez、Jesus Ramírez
DOI:10.1055/s-2005-865354
日期:——
Catalytic diboration of alkynes towards alkenyl diboronates provides suitable intermediates that can be converted into α-fluorinated and α,α-difluorinated carbonyl compounds via electrophilic fluorination with Selectfluor.
Treatment of α-chloro-α,α-difluorotoluene and α-chloro-α,α-difluoroanisole with chlorotrimethylsilane in the presence of magnesium in DMF led to their corresponding trimethylsilyl derivatives. These compounds are able to transfer their fluorinated group to various electrophilic substrates (carbonyl compounds, disulfides, phenyl isocyanate).