Regio‐ and Stereoselective Dirhodium( II )‐Catalysed Intramolecular C−H Insertion Reactions of α‐Diazo‐α‐(dialkoxyphosphoryl)acetamides and ‐acetates

Abstract α‐Diazo‐α‐(dialkoxyphosphoryl)acetates and ‐acetamides afforded α‐(dialkoxyphosphoryl)lactones and lactams, respectively, in moderate to high yields through dirhodium(II)‐catalysed intramolecular carbon−hydrogen insertion reactions. In the case of α‐diazo‐α‐(dialkoxyphosphoryl)acetamides a remarkable preference for the formation of γ‐lactam was observed, with stereocontrol in favour of the trans diastereomer. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)