Tandem Insertion-[1,3]-Rearrangement: Highly Enantioselective Construction of α-Aminoketones.

An enantioselective synthesis of α-aminoketone derivatives were readily available through a tandem insertion-[1,3] O-to-C rearrangement reaction. The rhodium salt and chiral N,N'-dioxide-indium(III) complex make up relay catalysis, which enables the O-H insertion of benzylic alcohols to N-sulfonyl-1,2,3-triazoles, and asymmetric [1,3]-rearrangement of amino enol ether intermediates, subsequently. Preliminary mechanistic studies suggested that the [1,3] O-to-C rearrangement step proceeded through an ion pair pathway.