N‐Phosphinyl Phosphoramide—A Chiral Brønsted Acid Motif for the Direct Asymmetric N,O‐Acetalization of Aldehydes

Fine-tuning the sites: The readily accessible N-phosphinyl phosphoramide 1 proved to be highly efficient and enantioselective in catalyzing the title reaction. The synthetic utility of this methodology was demonstrated with the first catalytic asymmetric synthesis of the analgesic pharmaceutical (R)-chlorothenoxazine (see scheme). 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.