Res. Chem. Intermed.
, Vol. 33, No. 6, pp. 481–486 (2007)
Also available online - www.brill.nl/rci
Conﬁgurational and conformational preferences in
stereoselective acylations of N -methyl-1,3-diaminopropane
with acyl chlorides
Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Pozna´n, Poland
Received 26 March 2006; accepted 20 October 2006
Abstract—Evidence for a stereoinduction proﬁle of the reaction of N -methyl-1,3-diaminopropane
with acyl chlorides has been provided. A possibility to engage in intramolecular CH
H−N interactions and the proton migration process to the methylamino group leads to the
E secondary amides carrying the N
N bridges, that show unusual spectroscopic
images. Empirical relations between the δ
chemical shift differences, the polarizability of the
CO(S) groups and hydrogen bonding strength have been found. Both
N-GHSQC and GHMBC
experiments provide insight into the nature of hydrogen bonding and conﬁrm the cyclic array of atoms.
Keywords: Ionic hydrogen bonding;
N spin–spin interactions; acetamides; benzamides.
Intramolecular hydrogen bonding interaction has the extraordinary capacity of
the acceleration of a variety of chemical reactions, may inﬂuence the stereos-
electivity and can greatly increase the synthetic signiﬁcance of the reactions
[1–7]. Previously, the unusual stabilization of N -[3-(methylamino)propyl](1-
thyminyl)acetamide hydrochloride by intramolecular N
N hydrogen bonding
and double dihydrogen bonding was observed . Little is known about the direct
reaction of acyl halides with diaminoalkanes. On the basis of the results of this pre-
vious work it can be expected that monoacylated diaminoalkanes can be stabilized
in the form of a hydrogen-bonded intramolecular ring.
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