Structure and wavelength modification in retinylidene iminium salts

Chemistry of Iminium Salts and Related Compounds

Chemistry of Iminium Salts and Related Compounds

Chemistry of Iminium Salts, Imines, and Related Compounds

Iminium Salts by Meerwein Alkylation of Ehrlich’s Aldehyde

4-(Dimethylamino)benzaldehyde is alkylated at the N atom by dialkyl sulfates, MeI, or Me3O BF4. In contrast, ethylation by Et3O BF4 occurs selectively at the O atom yielding a quinoid iminium ion. 4-(Diethylamino)benzaldehyde is alkylated only at O by either Et or Me oxonium reagent. The iminium salts are prone to hydrolysis giving the corresponding hydrotetrafluoroborates. Five crystal structu...

Enaminosulfones from 3-Trifloxypropene Iminium Salts: A 1,5(O5C) Trifluoromethylsulfonyl Shift*

Triflic anhydride (Tf2O) is the reagent of choice for the introduction of the trifluoromethylsulfonyl (CF3SO2) group into a variety of organic substrates, and the resulting compounds often have a unique chemical reactivity [1]. A case in point is given by 3-trifloxypropene iminium triflates which are obtained by O-sulfonylation of enaminones with Tf2O [2, 3] and which are suited for transformat...