On the Reaction of Cyanamides with N-Alkylnitrilium and N,N-Dialkylcyanamidium Salts
Rajab Abu-El-Halawa
Department of Chemistry, Al al-Bayt University, Mafraq 25113, Jordan Reprint requests to Prof. R. Abu-El-Halawa. E-mail: halawarajab@yahoo.com Z. Naturforsch.2009,64b,297 – 306; received October 27, 2008
Dedicated to Professor Johannes C. Jochims on the occasion of his 75thbirthday
N-Alkylnitrilium and N,N-dialkylcyanamidium salts 1 and 2 undergo ene reactions with cyanamides4to afford 2-azoniaallene salts7and9in which theN-alkylnitrilium salts1react as the ene, and the cyanamides4react as the enophile components. Competing with the ene reaction, N-alkylnitrilium salts1undergo [2++2+2] cycloaddition to furnish triazinium salts8. 2-Azoniaallene salts react with alcohols to afford alkoxy amino derivatives10and12, which yield iminium salts11 and ketals/acetals upon further reaction with alcohols. The constitution of the 2-azoniaallene7and9 and triazinium salts8was secured by elemental analyses and spectral properties (IR and NMR).
Key words:Ene Reaction, [2++2+2]-Cycloaddition, Nitrilium, Cyanamidium, 2-Azoniallene, Triazinium