Synthesis and characterisation of unusual tetraaminoalkenes (enetetramines)

Abstract

Two general routes are described for the synthesis of the title compounds from the reaction of either (A) the dimethyl acetal of N,N-dimethylformamide and an appropriate N,N′-bis(secondary amine), or (B) sodium hydride and a 4,5-dihydroimidazolium or tetrahydropyrimidinium salt. The following new compounds have been made: trans-R[graphic omitted][graphic omitted]R [R = Et and R′= Me (1a) or CH₂Ph (1b)] and R[graphic omitted][graphic omitted]R [n=m= 2 and R= Me (2a) or CH₂Ph (2b); n= 3, m= 2, and R= CH₂Ph (3); or n= 2, m= 3, and R= CH₂Ph (4)].

X-Ray data on crystalline [graphic omitted]R]₂(R = CH₂Ph) and (2b)[data in parentheses] show a short CC bond, 1.319(8)Å[1.329(5)Å], long C_sp²–N bonds, av. 1.437(11)Å[1.424(4)Å], with each of the four nitrogen atoms in a pyramidal sp³ environment.