Sulfonated polyanthracene-catalyzed highly efficient and chemoselective thioacetalization of carbonyl compounds and transthioacetalization of acetals and acylals
摘要:
A straightforward and highly efficient procedure for the thioacetalization of a variety of aldehydes and transthioacetalization of acylals and acetals in good to excellent yields using catalytic amounts of sulfonated polyanthracene (S-PAT) is reported. The reactions were carried out in the presence of 1,2-ethanedithiol and 1,3-propanedithiole at room temperature under solvent-free conditions. Thioacetals were also prepared by the reaction of aromatic ketone and dithiole using S-PAT under reflux conditions in H2O as green solvent.
3,3,9,9-Tetramethyl-1,5,7,11-tetraoxaspiro[5.5]undecane is introduced as a new, stable and chemoselective reagent for the protection of aldehydes and ketones under mild reaction condition in high yield.