Highlydiastereo- and enantioselective 1,6-addition of 1,3-ketoamides to p-quinone methides (p-QMs) using chiral NHCs as Brønsted base catalysts is developed. The reaction is based on the utilization of a 1,3-ketoamide having acidic N–H that forms a chiral ion-pair consisting of the enolate and the azolium ion. Different β-ketoamides and functionalized p-QMs are applicable to the reaction. Synthetic
Knorr Cyclizations and Distonic Superelectrophiles
作者:Kiran Kumar Solingapuram Sai、Thomas M. Gilbert、Douglas A. Klumpp
DOI:10.1021/jo7013092
日期:2007.12.1
theoretical methods. The results of these studies indicate that β-ketoamides such as acetoacetanilide undergo diprotonation at the two carbonyl oxygen atoms to form distonic superelectrophiles. Direct observation of a dicationic superelectrophile was achieved by low-temperature 1H, 15N, and 13C NMR from FSO3H−SbF5−SO2ClF solutions. In synthetic studies, the Brønsted superacid CF3SO3H is found to be an effective
通过实验和理论方法研究了酸催化的克诺尔环化反应。这些研究的结果表明,β-酮酰胺(如乙酰乙酰苯胺)在两个羰基氧原子处经历了双质子化反应,形成了扭曲的超亲电子体。通过FSO 3 H-SbF 5 -SO 2 ClF溶液的低温1 H,15 N和13 C NMR可以直接观察到阳离子型超亲电子试剂。在合成研究中,发现布朗斯台德超强酸CF 3 SO 3 H是克诺尔环化的有效酸催化剂。
The Preparation and Cyclization of Substituted Acetoacetanilides
作者:A. Langley Searles、Richard J. Kelly
DOI:10.1021/ja01627a095
日期:1955.11
Unexpected formation of new bicyclic γ-lactams by dimerization of α-chloroacetoacetanilides
Novel and unusual dimerization reaction of alpha-chloroacetoacetanilide under basic reaction condition to give structurally unique 6-oxa-3-azabicyclo[3.1.0]hexane was described. (c) 2008 Published by Elsevier Ltd.
Ritchie, Journal and Proceedings - Royal Society of New South Wales, 1944, vol. 78, p. 164,167