Indium(III)-Catalyzed Synthesis of Primary Carbamates and N-Substituted Ureas

An indium triflate-catalyzed synthesis of primary carbamates from alcohols and urea as an ecofriendly carbonyl source has been developed. Various linear, branched, and cyclic alcohols were converted into the corresponding carbamates in good to excellent yields. This method also provided access to N-substituted ureas by carbamoylation of amines. All the products were obtained by simple filtration or crystallization, without the need for chromatographic purification. Mechanistic investigations suggest that the carbamoylation reaction proceeds through activation of urea by O-coordination with indium, followed by nucleophilic attack by the alcohol or amine on the carbonyl center of urea. The inexpensive and easily available starting materials and catalyst, the short reaction times, and the ease of product isolation highlight the inherent practicality of the developed method.

Indium triflate catalysed 3-aza-Cope rearrangement of amino acid derived α,β-unsaturated esters to alkylidene oxindoles

The first examples of amino acid derived α,β-unsaturated esters to Z-alkylidene oxindoles via 3-aza-Cope rearrangement using In(OTf)3 are reported.

An efficient and eco-friendly synthesis of 2-pyridones and functionalized azaxanthone frameworks via indium triflate catalyzed domino reaction

A green and efficient one-pot method has been developed for the synthesis of 2-pyridone and functionalized azaxanthone frameworks using indium triflate as an environmentally friendly, reusable catalyst.