%0 Generic
%A Neal, Taylor
A.
%A Eippert, Allyson B.
%A Chivington, Austin
%A Jamison, Andrew
%A Chukwuma, P. Chukwunalu
%A Moore, Curtis E.
%A Neal, Jennifer F.
%A Allen, Heather C.
%A Wysocki, Laura M.
%A Paul, Noel M.
%A Badjić, Jovica D.
%D 2020
%T One-Pot Aldol Cascade
for the Preparation of Isospiropyrans,
Flavylium Salts, and bis-Spiropyrans
%U https://acs.figshare.com/articles/dataset/One-Pot_Aldol_Cascade_for_the_Preparation_of_Isospiropyrans_Flavylium_Salts_and_bis-Spiropyrans/12465149
%R 10.1021/acs.joc.0c00825.s003
%2 https://acs.figshare.com/ndownloader/files/23086418
%K electron-withdrawing groups
%K SiCl 4
%K switchable photochromic
%K electron-donating groups
%K positions 4
%K Flavylium Salts
%K thermochromic characteristics
%K EWG
%K tandem aldol condensations
%K EDG
%K One-Pot Aldol Cascade
%K molar equivalents
%X We probed tandem aldol condensations
of sixteen o-hydroxyacetophenones, carrying electron-withdrawing
and -donating
groups at positions 4 and 5, using five molar equivalents of SiCl4 in anhydrous ethanol. Substrates carrying electron-withdrawing
groups (EWGs) (0 < ∑σ > 0.63) populated the equilibria
with isospiropyrans (12–74% yield), while those carrying electron-donating
groups (EDGs) (∑σ < −0.31) gave flavylium salts
(50–80%) or thermochromic bis-spiropyrans (73%). The results
are of interest for developing novel organic materials possessing
switchable photochromic and thermochromic characteristics.
%I ACS Publications