| Abstract
| - A set of C2-chiral diamines 18−21 based on 1,6-diazacyclodecane have been identified whoseconjugate acids are predicted by B3LYP/6-31G* calculations to have pKa values of ∼23−6 on the waterscale (pKa = 30−33 in MeCN); they are also expected to be kinetically active, but essentially nonnucleophilic.Strain relief on protonation largely determines the basicity of these compounds, and the key to the designof stronger bases is limiting conformational freedom, especially by preventing nitrogen inversion, throughthe introduction of additional ring fusions. 15,16-Dimethyl-15,16-diazatricyclo[9.3.1.14,8]hexadecane (20)is examined in detail and shown to exist in 10 diastereomeric forms as a result of in-/out-isomerism. Thepredicted pKa values for these diastereomers range over 14 log units.
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