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. A highly enantioselective tandem O−H insertion–[1,3]‐alkyl shift reaction of benzylic alcohols and rhodium azavinyl carbenoids was developed by using relay catalysis of dirhodium(II) carboxylates and a chiral N,N′‐dioxide‐indium(III) complex. This strategy provides an efficient and succinct access to structurally diverse chiral α‐aminoketones with good yields and excellent enantioselectivities.