15677-00-6Relevant articles and documents
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
supporting information, p. 242 - 246 (2021/01/13)
Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.
Iron-catalyzed asymmetric epoxidation of β,β-disubstituted enones
Nishikawa, Yasuhiro,Yamamoto, Hisashi
supporting information; experimental part, p. 8432 - 8435 (2011/07/29)
The combination of Fe(OTf)2 and novel phenanthroline ligands enables the catalytic asymmetric epoxidation of acyclic β,β- disubstituted enones, which have been a heretofore inaccessible substrate class. The reaction provides highly enantioenriched α,β-epoxyketones (up to 92% ee) that can be further converted to functionalized β-ketoaldehydes with an all-carbon quaternary center.
Discovery of a series of pyrrolidine-based endothelin receptor antagonists with enhanced ET(A) receptor selectivity
Boyd, Steven A.,Mantei, Robert A.,Tasker, Andrew S.,Liu, Gang,Sorensen, Bryan K.,Henry Jr., Kenneth J.,Von Geldern, Thomas W.,Winn, Martin,Wu-Wong, Jinshyun R.,Chiou, William J.,Dixon, Douglas B.,Hutchins, Charles W.,Marsh, Kennan C.,Nguyen, Bach,Opgenorth, Terry J.
, p. 991 - 1002 (2007/10/03)
Endothelins, ET-1, ET-2, and ET-3 are potent vasoconstricting and mitogenic 21-amino acid bicyclic peptides, which exert their effects upon binding to the ET(A) and ET(B) receptors. The ET(A) receptor mediates vasoconstriction and smooth muscle cell proliferation, and the ET(B) receptor mediates different effects in different tissues, including nitric oxide release from endothelial cells, and vasoconstriction in certain vascular cell types. Selective antagonists of endothelin receptor subtypes may prove useful in determining the role of endothelin in various tissue types and disease states, and hence as therapeutic agents for such diseases. The pyrrolidine carboxylic acid A-127722 has been disclosed as a potent and ET(A)-selective antagonist, and is currently undergoing clinical trials. In our efforts to find antagonists with altered selectivity (ET(A)-selective, ET(B)-selective, or nonselective), we investigated the SAR of the 2-substituent on the pyrrolidine. Compounds with alkyl groups at the 2-position possessed ET(A) selectivity improved over A-127722 (1400-fold selective), with the best of these compounds showing nearly 19,000-fold selectivity. Copyright (C) 1999 Elsevier Science Ltd.