Alkanes Bearing a Primary CF2H Group

Typical 19F chemical shifts for n-C H2 +1CF2H compounds are between -116 and -117 ppm, with the usual branching effects being observed. Thus, a CF2H group attached to a secondary carbon is more shielded (7-10 ppm), and the one attached to a tertiary carbon is still further upheld. 

Coupling for CF2H Groups Within Chiral Compounds. 

In this case, the two fluorines each appear as doublets (2/FF) of doublets (2/Fh) of triplets (3/FH) at -116.3 and -118.9, each with coupling constants of 289, 57, and 16 Hz. 

FIGURE 4.4. 19F NMR spectrum of 2-cyano-4,4-dill iioro- l-(17/-i ndol-l-yl)butan- 

FIGURE 4.5. 19F NMR spectrum of 2-chloro-4,4-difluoro-l-(l//-indol-l-yl)butan-1-one 

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