1361583-28-9Relevant academic research and scientific papers
Mechanistic Insight into Palladium-Catalyzed Cycloisomerization: A Combined Experimental and Theoretical Study
Mekareeya, Aroonroj,Walker, P. Ross,Couce-Rios, Almudena,Campbell, Craig D.,Steven, Alan,Paton, Robert S.,Anderson, Edward A.
supporting information, p. 10104 - 10114 (2017/08/03)
The cycloisomerization of enynes catalyzed by Pd(OAc)2 and bis-benzylidene ethylenediamine (bbeda) is a landmark methodology in transition-metal-catalyzed cycloisomerization. However, the mechanistic pathway by which this reaction proceeds has remained unclear for several decades. Here we describe mechanistic investigations into this reaction using enynamides, which deliver azacycles with high regio- and stereocontrol. Extensive 1H NMR spectroscopic studies and isotope effects support a palladium(II) hydride-mediated pathway and reveal crucial roles of bbeda, water, and the precise nature of the Pd(OAc)2 pre-catalyst. Computational studies support these mechanistic findings and lead to a clear picture of the origins of the high stereocontrol that can be achieved in this transformation, as well as suggesting a novel mechanism by which hydrometalation proceeds.
Palladium- and ruthenium-catalyzed cycloisomerization of enynamides and enynhydrazides: A rapid approach to diverse azacyclic frameworks
Walker, P. Ross,Campbell, Craig D.,Suleman, Abid,Carr, Greg,Anderson, Edward A.
, p. 9139 - 9143 (2013/09/12)
I want to ride my azacycle: The title reaction of enynamides affords a wide diversity of azacycles. The reactions are high-yielding, highly stereoselective, and proceed rapidly under mild reaction conditions. Equivalent transformations using enynhydrazides offer new routes to pyrazole and indazole scaffolds. Boc=tert-butoxycarbonyl, EWG=electron-withdrawing group, Ns=4-nitrobenzenesulfonyl, Ts=4-toluenesulfonyl. Copyright
Reductive cyclization of bromoenynamides with alcohols as hydride source: Synthesis and reactions of 2-amidodienes
Greenaway, Rebecca L.,Campbell, Craig D.,Chapman, Helen A.,Anderson, Edward A.
supporting information, p. 3187 - 3194 (2013/01/15)
Under basic conditions in alcoholic solvents, bromoenynamides undergo palladium-catalyzed cyclization to cyclic 2-amidodienes in good to excellent yields. This process represents the first use of an alcohol as a hydride source in an alkyne carbopalladation/termination sequence, with the site selectivity of the reduction showing a strong dependence on the tethering ring size (5-8), and the nature of the alcohol and base. Reaction of the dienes with a range of dienophiles (including alkenes, alkynes and arynes) under various conditions gives bi- and tricyclic azacycles, which can be further oxidized to the aromatic azacycles. Copyright
Palladium-catalyzed cascade cyclization of ynamides to azabicycles
Greenaway, Rebecca L.,Campbell, Craig D.,Holton, Oliver T.,Russell, C. Adam,Anderson, Edward A.
, p. 14366 - 14370 (2012/02/04)
Cascade reactions: A modular assembly of azabicycles by using a cascade cyclization/Suzuki coupling/6π-electrocyclization of bromoenynamides is reported (see scheme). The reaction offers a wide substituent scope on the bicyclic aminodiene products, which can be selectively oxidized as a general approach to aromatic azabicycles.
