80077-72-1

The electrochemical reduction of some fluorohalocarbons in the presence of trimethylchlorosilane is followed by formation of the corresponding fluoroalkyltrimethylsilanes. CF3SiMe3, CFCl2SiMe3, CF3CCl2SiMe3 and (EtO)2P(O)CF2SiMe3 were obtained with current efficiency 20-50%. Voltammetric data are presented.

The first enantioselective phosphonyldifluoromethylation is enabled by the use of diethyl (difluoro(trimethylsilyl)-methyl)phosphonate reagent as a latent pronucleophile in the Lewis base catalyzed substitution of allylic fluorides. The reaction proceeds

A method for siladifluoromethylation of dialkyl phosphonates and secondary phosphine oxides with TMSCF3 to produce nucleophilic PV-CF2- transfer reagents is disclosed, with multigram scale reactions included. Condition-dependent divergent reactivity under the established conditions is demonstrated by the formation of trifluoromethylphosphines. Both one-pot transformations are operationally simple and employ inexpensive materials. Mechanistic investigations suggest the divergent reactivity originates from a common intermediate, with Li+ concentration directing the chemoselectivity.

Addition of organotrimethylsilane reagents to chiral N-tert-butanesulfinyl imines can be achieved in good yields and with excellent diastereoselectivities by employing TMSO-/Bu4N+ as a Lewis base activator in THF. A variety of aliphatic, aromatic, heteroaromatic and organometallic chiral imines were utilised as electrophiles for the synthesis of enantioenriched N-tert-butanesulfinyl amides. Remarkably, the same sets of reaction conditions could be used with a highly diverse range of bench-stable organotrimethylsilane reagents, which highlights the generality and robustness of this methodology. Addition of organotrimethylsilane reagents to chiral N-tert-butanesulfinyl imines can be achieved in good yields and with excellent diastereoselectivities by employing TMSO-/Bu4N+ as a Lewis base activator in THF. A variety of aliphatic, aromatic, heteroaromatic and organometallic chiral imines were utilised as electrophiles for the synthesis of enantioenriched N-tert-butanesulfinyl amides, highlighting the generality and robustness of this methodology.

Nucleophilic fluoroalkylation reactions of imines and enamines with α-phenylthio, α-phenylsulfonyl, and α-diethylphosphoryl substituted fluorinated silanes have been investigated. The reactions are promoted by hydrofluoric acid generated in situ from pota

A new nucleophilic difluoromethylenation of aldehydes and ketones using diethyl difluoro(trimethylsilyl)methylphosphonate (1) has been achieved. The reactive carbanion species were generated under mild reaction conditions with a catalytic amount of initiator. This methodology was compatible with non-enolizable and in some cases with enolizable aldehydes and ketones and provided a straightforward access to phosphates of syn and anti 2,2-difluoro-1,3-diols.

A new NMR chemical shift standard and pH indicator, difluorotrimethylsilanylphosphonic acid (DFTMP), is described, and the utility of this reagent is demonstrated for in situ determination of pH in complex biofluids. The pH dependence of this reagent allows accurate in situ determination of aqueous solution pH to within an RMSE of 0.02 pH units over a pH range of 5 to 8. Advantages of this reagent over previously described pH-sensitive components include (1) lack of metal binding affinity, (2) minimal disturbance of endogenous spectral regions, and (3) the potential to function as a multinuclear pH indicator and chemical shift reference point for 19F, 1H, and 31P nuclei. This reagent will be generally useful for NMR experiments on biological systems where the pH needs to be accurately measured at the moment of data acquisition. Copyright

When (EtO)2P(O)CF2Br (1) is treated with isopropylmagnesium chloride in THF at low temperature it gives a magnesium species (2) which undergoes reactions with strong electrophiles (HCl, TMSCl, halogens, aldehydes and ketones). The formation of products depends strongly on the reaction conditions. With 1.5 equivalents of 2 between - 78 and 0°C, a conversion of more than 90% of aldehydes and ketones into 2-hydroxyphosphonates (7 and 8) can be achieved. These compounds (7 and 8) in the presence of base (NaH, LDA) are rearranged into 2,2-difluoroethylphosphates without concomitant formation of 1,1-difluoroolefines.

The synthesis of the cyclohexylammonium salts of (1RS, 3S)-3,4-dihydroxy-1-fluorobutylphosphonic acid 3 and (S)-difluoro-3,4-dihydroxybutylphosphonic acid 4 is reported. These compounds are fluorinated phosphonate analogues of sn-glycerol-3-phosphate wher

The synthesis of the cyclohexylammonium salts of 3-(S),4-dihydroxy-1(R,S)-fluorobutylphosphonic acid 3 and 1,1-difluoro-3-(S),4-dihydroxybutylphosphonic acid 4 is reported; 3 is a better substrate for NADH linked sn-glycerol-3-phosphate dehydrogenase than the difluoromethylenephosphonate 4; a comparative study of the CH2-, CHF- and CF2-phosphonate analogues of sn-glycerol-3-phosphate is reported.

[1-14C]-2,2-Difluoroethene was synthesized from [14C]-formaldehyde using a modification of the Wadsworth-Emmons reaction, via formation of the intermediate (EtO)2P(O)CF214CH2OSiMe3. This highly volatile product was collected in a liquid nitrogen trap at a purity of >97% and specific activity of 0.2 mCi/mmol, with yields of 10-15%.

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The action of lithium diisopropylamide on diethyl difluoromethylphosphonate gives the title reagent which reacts with various electrophiles to introduce difluoromethylene or difluoromethyl unit.

Diethyl bromodifluoromethylphosphonate reacts readily with cadmium metal to form a stable cadmium complex.Depending on solvent, this functionalized organocadmium reagent exhibits stability for days to months.It reacts with a variety of electrophiles and serves as a synthetically useful source for the introduction of the difluoromethylene phosphonate group into organic compounds.