The effect of heteroatoms at the α-position of aldimines on the 1JC—H coupling constant at the sp2-carbon

The effect of α-functionalization of a great variety of aldimines on the 1Jc—H coupling constant at the sp2 aldimine carbon has been determined. This comparative study includes α-tert-butyl, α-alkoxy-, α-phenyl-, α-hydroxy-, α-sulfenyl-, α,α-disulfenyl-, α-alkylamino-, α-chloro-, α,α-dichloro-, α-bromo-, α,α-dibromo-, and α,α,α-trichloroaldimines. Depending upon the α-heterofunctionalization the 1Jc—H value for (E)-aldimines varied over a great range of about 150–178 Hz.