Direct and Highly Diastereoselective Synthesis of Azaspirocycles by a Dysprosium(III) Triflate Catalyzed Aza‐Piancatelli Rearrangement

Ring the changes: The first example of an intramolecular aza-Piancatelli rearrangement is reported. Dysprosium(III) trifluoromethanesulfonate efficiently catalyzes the synthesis of functionalized azaspirocycles in a trans-selective manner by a 4π electrocyclization of elaborated furylcarbinols (see scheme; Tf=trifluoromethanesulfonyl). Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.