mediated the carbonylation of ethyl 2-diazo-2-phenylacetate and produced ketene as a key intermediate. The transformation of ketene to amide was achieved by the nucleophilic addition of amine. We also made an effort to detect the formation of a ketene intermediate from the reaction between ethyl 2-diazo-2-phenylacetate and [Co2(CO)8] in the absence of a nucleophile. The IR spectroscopy revealed the formation
Cascade Wolff Rearrangement and Double <i>N</i>‐Acylation: A Cyclization of <i>α</i>‐Diazoketones with 2‐aminopyridines or 3‐aminopyrazoles to Synthesize Fused Pyrimidinediones
A cascade Wolffrearrangement and double N-acylation reaction has been developed for the synthesis of fused pyrimidinediones in one-pot under air. These reactions were performed with α-diazoketones and 2-aminopyridines or 3-aminopyrazoles under catalyst- and additive-free conditions. The protocol avoided traditional purification procedures, such as organic solvent extraction and column chromatography
作者:Ashok K. Basak、Naoyuki Shimada、William F. Bow、David A. Vicic、Marcus A. Tius
DOI:10.1021/ja103028r
日期:2010.6.23
An organocatalytic asymmetric Nazarov cyclization of diketoesters that proceeds by means of a dual activation mechanism has been developed. Screening of a number of catalysts led to a new thiourea that incorporates a primary amino group. The method gives rise to cyclic products with two adjacent quaternaryasymmetriccarbon atoms, one of which is an all-carbon stereocenter, with complete or nearly