%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