Formyl fluoride, formamides

Nitrogen trifluoride Difluoramine Nitrous acid Nitric acid Cyano fluoride Formyl fluoride Carbonyl fluoride Acetyl fluoride Acetyl cyanide Isocyanic acid Methyl isocyanate Formamide Nitromethane Nitrobenzene... 

Many carbonyl addition and substitution reactions are carried out under acidic conditions or in the presence of Lewis acids. Qualitatively, protonation or complexation increases the electrophilicity of the carbonyl group. The structural effects of protonation have been examined for formaldehyde, acetaldehyde, acetone, formamide, and formyl fluoride. These effects should correspond to those in more complex carbonyl compounds. Protonation results in a substantial lengthening of the C=0 bond. The calculated [B3LYP/ 6-31-H-G(phase proton affinities reflect the trend of increasing basicity with donor groups (CH3, NH2) and decreased basicity for fluorine. 

ALDEHYDE SYNTHESIS CO + HCI (Gattermann- Koch) Formyl fluoride Acetic-formic anhydride CO HCN (Gattermann) BrCN (Karrer) Formamides (Vilsmeier) Formic acid Ortho- formates... 

The reaction of tertiary formamides with sulfur tetrafluoride in the presence of potassium fluoride leads to replacement of both the carbonyl oxygen and formyl hydrogen atoms by fluorine. The formyl group is directly converted into the trifluoromethyl group to give N-(trifluoromethyl)amines which are isolated in almost quantitative yield (see Section 8.2.10.). Thus, dimethylformamide, diethylformamide, piperidinc-l-carbaldehyde, morpholine-1-carbaldehyde and ethyl(phenyl)formamide were converted into the corresponding A -(tri-fluoromethyl)amines 11.175... 

The aminoolefin (82) obtained from the acetanilide 80 in a three-step sequence of reactions was converted to the formamide 83 in 88% yield by sequential formylation and methylation. Treatment of 83 with methyl trifluoromethanesulfonate followed by trimethylsilylmethylamine gave the formamidine 84 in 77% yield. Methylation of 84 with methyl trifluo-romethanesulfonate, followed by exposure of the resulting salt (24) to tetra-zi-butylammonium fluoride brought about a facile generation of the... 

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