A type 2 N-acylnitroso intramolecular Diels-Alder reaction followed by reductive N-O bond cleavage formed the B and C rings of the Stemona alkaloid stenine. Further elaboration provided the functionalized tricyclic core.
A type 2 N-acylnitroso intramolecular Diels-Alder reaction followed by reductive N-O bond cleavage formed the B and C rings of the Stemona alkaloid stenine. Further elaboration provided the functionalized tricyclic core.
Catalytic Enantioselective Conjugate Allylation of Unsaturated Methylidene Ketones
作者:Laura A. Brozek、Joshua D. Sieber、James P. Morken
DOI:10.1021/ol102982b
日期:2011.3.4
The use of unsaturated methylidene ketones in catalytic conjugate allylations allows a significant expansion in substrate scope and, with appropriate chiral ligands, occurs in a highly enantioselective fashion.
Regioselective Iridium-Catalyzed Asymmetric Monohydrogenation of 1,4-Dienes
作者:Jianguo Liu、Suppachai Krajangsri、Thishana Singh、Giulia De Seriis、Napasawan Chumnanvej、Haibo Wu、Pher G. Andersson
DOI:10.1021/jacs.7b06829
日期:2017.10.18
A highly efficient regio- and enantioselective monohydrogenation of 1,4-dienes has been realized using an iridium catalyst with a chiral N,P-ligand under mild conditions. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the meta- or para-position. Substrates having substituents with functionalities such as silyl protected alcohols or ketals
Scalable Total Synthesis and Biological Evaluation of Haouamine A and Its Atropisomer
作者:Noah Z. Burns、Irina N. Krylova、Rami N. Hannoush、Phil S. Baran
DOI:10.1021/ja903745s
日期:2009.7.8
A total synthesis of the complex, bent aromatic ring-containing marine alkaloid haouamine A is achieved through a route in which every step (with the exception of the final deprotection) is performed on a gram-scale. This is accomplished through the development of a method for the dehydrogenation of cyclohexenones that allows for point-to-planar chirality transfer. This strategy makes it possible to program the desired atropisomeric outcome from a simple chiral cyclohexenone. By synthesizing atrop-haouamine A, this work has firmly established that natural haouamine exists as a single, nonequilibrating atropisomer. Finally, biological investigations demonstrate that the bent aromatic ring of this natural product is critical for anticancer activity against PC3 cells.