Effect of temperature modulations on TEMPO-mediated regioselective oxidation of unprotected carbohydrates and nucleosides

Synthesis of Acids and Amino Acids by Selective Oxidation of Primary Hydroxyl Groups to Carboxylic acids in Sugars

“…Other reported methods for these transformations involve, either the use of expensive oxidizing agents (Kochkar et al, 2000) and/or temperature control or procedures that were again not compatible with base-and acid-sensitive functionalities in the molecule (Arian et al, 1995). These limitations were nicely addressed in a recent report, offering an alternative route to these sugar acids (Mahipal et al, 2018). Surprisingly, this report does not include the preparation of SAAs and in some cases failed to yield the required carbohydrate acids.…”

Hypervalent Iodine Compounds in Carbohydrate Chemistry: Glycosylation, Functionalization and Oxidation

“…Later on, Vankar and coworkers published another method of direct oxidation of 3‐ O protected glycals to the corresponding enones addressing the previous limitations [64] . It is worth mentioning here that the combination of PhI(OAc) 2 (PIDA) and TEMPO have routinely been used to oxidize primary C6‐OH of sugars to carboxylic acids, enabling late‐stage construction of uronic acids [65] . Similar to this Vankar and coworkers used the combination of TEMPO and PIFA for the oxidation of the enone and they also used water that afforded high yields of the corresponding enones (Scheme 13) with optimum conditions achieved when 2eq of PIFA, 0.2 eq of TEMPO and 1 eq of water were used.…”