InCl3 as a powerful catalyst for the acetylation of carbohydrate alcohols under microwave irradiation

Indium triflate catalyzed peracetylation of carbohydrates

“…31 An InCl 3 -catalyzed peracetylation reaction using microwave irradiation in acetonitrile was reported by Das and co-workers. 32 We found that reactions that were performed according to our protocol described above (5mol% In(OTf) 3 , one hour, 0 °C, neat acetic anhydride) could also be performed under microwave irradiation. We irradiated mannose and N-acetyl glucosamine for 5 minutes at room temperature in a sealed tube with 150 watts to afford peracetylated products (Scheme 3).…”

Conversion of Carbohydrates Under Microwave Heating

“…Microwave heating affords also convenient results for the complete acetylation of totally Ounprotected mono-and disaccharides in 90 sec at 720 Watt under closed vessel conditions using indium(III) chloride catalyst. Reactions performed in acetonitrile with stoichiometric amounts of anhydride acetic are quantitative and affords predominantly the peracetylated form (Das, 2005). Partial acetylation of carbohydrates is usually achieved with acetyl chloride and pyridine.…”

A Journey into Recent Microwave‐Assisted Carbohydrate Chemistry

“…Among already known methods for peracetylation, a very common and inexpensive protection strategy in carbohydrate synthesis, Cloninger and co-workers [10] used Das et al's method [3] employing catalytic In(OTf) 3 in neat Ac 2 O, which works well for mannose and N-acetylglucosamine, being high yielding and efficient. The use of In(OTf) 3 eliminated the need for unpleasant solvents, such as pyridine, with the advantage of being affordable, nontoxic, water tolerant, and noncorrosive.…”