Preparation of 2-diazo-2-oxopiperidin-3-yl-3-oxopropanoates. Useful reagents for Rh(II)-catalyzed cyclization-cycloaddition chemistry

Abstract

2-Diazo-2-oxopiperidin-3-yl-3-oxopropanoates containing a tethered indolyl group have been identified as useful intermediates for the Rh(II)-catalyzed cyclization-cycloaddition cascade for the synthesis of the core skeleton of various aspidosperma alkaloids. Several synthetic methods were developed to rapidly construct these important diazo imide substrates using cheap and readily available reagents.