Introduction of N-sulfonic acid poly(4-vinylpyridinum) chloride as an efficient and reusable catalyst for the chemoselective 1,1-diacetate protection and deprotection of aldehydes

Fe3O4@SiO2-imid-PMAn as a Novel, Efficient and Reusable Magnetic Nanocatalyst for the Chemoselective Preparation and Deprotection of 1,1-Diacetates

“…This result may be due to the strong electron donation of dimethylamino and NH groups. Also, a degree of tautomerization may occur with formation of a quininoid structure, which decreases the reactivity of the aldehydic carbonyl group (Shirini and Jolodar 2012).…”

N-Sulfonic acid poly(4-vinylpyridinium) hydrogen sulfate as an efficient and reusable solid acid catalyst for one-pot synthesis of xanthene derivatives in dry media under ultrasound irradiation

“…Poly(4-vinylpyridinium) hydrogen sulfate was prepared and used in the variety of organic transformations [36 and 38]. Very recently, The synthesis of N-sulfonic acid poly(4-vinylpyridinium) chloride [NSPVPC] and its applications in the chemoselective 1,1-diacetate protection and deprotection of aldehydes [34] and N-Boc protection of amines [35] was described. Herein, and in continuation of these studies, we wish to report the application of another analogue of Solid Acid Functionalized Poly(4-vinylpyridine) [SAFPVP], namely, N-sulfonic acid poly(4-vinylpyridinium) hydrogen sulfate (NSPVPHS) [40] as a reusable heterogeneous catalyst in the promotion of the synthesis of xanthene derivatives in dry media at significantly milder reaction conditions than those known in literature (Scheme 1).…”

Poly(4-vinylpyridinium) perchlorate as an efficient and recyclable catalyst for the synthesis of biscoumarins and bisindoles

“…As part of our ongoing research into the application of solid acid catalysts in organic reactions [38][39][40], and in light of the growing interest in the use of indole and coumarin derivatives in medicinal chemistry, we recently became interested in investigating the use of the newly reported polymer-based solid acid catalyst [P(4-VPH)ClO4] (Scheme 1) [41] for the synthesis of 3,3'-(arylmethylene)bis(4-hydroxycoumarins) and bis (indolyl) methanes.…”