10.1021/jo991011h.s003
Alan C. Spivey
Alan C.
Spivey
Tomasz Fekner
Tomasz
Fekner
Sharon E. Spey
Sharon E.
Spey
Harry Adams
Harry
Adams
Configurationally Stable Biaryl Analogues of
4-(Dimethylamino)pyridine: A Novel Class of Chiral Nucleophilic
Catalysts
American Chemical Society
1999
biaryl axes
methyl
DMAP
rotation
pyridine core 16
configurationally
chiral nucleophilic catalysts
Biaryls 55
Chiral Nucleophilic Catalysts
biaryls 31
Comparative HPLC studies
Compounds 55
Novel Class
biaryl axis
Ar
Configurationally Stable Biaryl Analogues
ambient temperature
atropisomeric analogues
acyl transfer
pyrrolidino substituent ortho
novel class
1999-12-04 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Configurationally_Stable_Biaryl_Analogues_of_4-_Dimethylamino_pyridine_A_Novel_Class_of_Chiral_Nucleophilic_Catalysts/3719196
A short synthetic approach toward a novel class of chiral nucleophilic catalysts, the dissymmetry
of which stems from restricted rotation about an Ar−Ar bond, has been developed. The key steps
of the synthesis include preparation of a nucleophilic 1-methyl-2-pyrrolino[3,2-<i>c</i>]pyridine core <b>16</b>
by <i>ortho</i>-lithiation and creation of the biaryl axes via Suzuki cross-coupling reactions. Comparative
HPLC studies of racemization for configurationally labile biaryls <b>31</b>, <b>38</b>, and <b>43</b> containing 1-methyl-2-pyrrolino[3,2-<i>c</i>]pyridine, 4-(dimethylamino)pyridine, and 4-(1-pyrrolidino)pyridine cores, respectively, have demonstrated that a pyrrolidino substituent <i>ortho</i> to the biaryl axis is optimal for
slowing Ar−Ar rotation. Biaryls containing all three cores have been shown to retain DMAP-like
catalytic activity in the acylation of a hindered alcohol. Biaryls <b>55</b> and <b>56</b>, which are configurationally stable at ambient temperature, have also been prepared via modification of configurationally
labile derivatives. Compounds <b>55</b> and <b>56</b> in optically pure form should provide a useful starting
point for studies on catalytic asymmetric acyl transfer using atropisomeric analogues of DMAP.