Fig. 3. Scope of NHC catalyzed HDE with enals (20 examples) and aliphatic aldehydes (23 examples).
a, Scope of NHC catalysed HDE reactions of enals. The reaction details are given in section 4 in SI. b, Scope of NHC catalysed HDE with aliphatic aldehydes. c, Amine catalyzed selective α-deuteration of bis-deuterated aldehydes. Some sites in 10a, 10b, 10d, 10e, 10f and 12f (shown in their structures and the deuteration percentage indicated in bracket) are slightly deuterated observed by 2H NMR.