- Catalytic formal cycloadditions between anhydrides and ketones: Excellent enantio and diastereocontrol, controllable decarboxylation and the formation of adjacent quaternary stereocentres
-
It has been shown for the first time that enolisable anhydrides can participate in highly efficient and diastereo/enantioselective additions to activated ketones. In these reactions the anhydride component formally acts (initially) as the nucleophilic component. These processes are promoted by novel, readily prepared urea-substituted cinchona alkaloid-derived catalysts at low loadings under mild conditions. Three classes of enolisable anhydride and three different types of activated ketone were shown to be compatible with the process-generating a diverse range of structurally distinct and densely functionalised lactone products with the formation of two new stereocentres, one of which is quaternary. In one example, a product incorporating two contiguous quaternary stereocentres (one all carbon) was formed with outstanding enantiocontrol. It has been shown in the case of glutaconic anhydride derivatives that the cycloaddtion process is reversible, and can be accompanied by decarboxylation and olefin isomerisation. Reaction conditions can be modified to give access to three types of product with good-excellent ee.
- Cornaggia, Claudio,Gundala, Sivaji,Manoni, Francesco,Gopalasetty, Nagaraju,Connon, Stephen J.
-
supporting information
p. 3040 - 3046
(2016/03/19)
-
- Cationic Ir/Me-BIPAM-catalyzed asymmetric intramolecular direct hydroarylation of α-ketoamides
-
Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various types of optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities (84-98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod) 2](BArF4) and the chiral O-linked bidentate phosphoramidite (R,R)-Me-BIPAM. Carbon's got a brand new bond: Asymmetric intramolecular direct hydroarylation of α-ketoamides gives various optically active 3-substituted 3-hydroxy-2-oxindoles in high yields with complete regioselectivity and high enantioselectivities. This is realized by the use of an asymmetric cationic iridium complex formed in situ (see Scheme).
- Shirai, Tomohiko,Ito, Hajime,Yamamoto, Yasunori
-
supporting information
p. 2658 - 2661
(2014/03/21)
-
- Synthesis and pharmacological characterization of constrained analogues of Vestipitant as in vitro potent and orally active NK1 receptor antagonists
-
A focused exploration targeting conformationally restricted analogues of Vestipitant, resulted in the discovery of novel, in vitro potent NK1 antagonists. In particular, two of the compounds reported exhibited a good pharmacokinetic (PK) profile and produced anxiolytic-like effects in the gerbil foot tapping (GFT) in vivo model.
- Sabbatini, Fabio M.,Fabio, Romano Di,Griffante, Cristiana,Pentassuglia, Giorgio,Zonzini, Laura,Melotto, Sergio,Alvaro, Giuseppe,Capelli, Anna M.,Pippo, Lara,Perdona', Elisabetta,Denis, Yves St.,Costa, Silvano,Corsi, Mauro
-
scheme or table
p. 623 - 627
(2010/06/12)
-
- The synthesis and structure-activity relationships of 1,3-diaryl 1,2,4-(4H)-triazol-5-ones: A new class of calcium-dependent, large conductance, potassium (maxi-K) channel openers targeted for urge urinary incontinence
-
A series of 1,3-diaryl 1,2,4-(4H)-triazol-5-ones was prepared and shown by electrophysiological analysis to activate a cloned maxi-K channel mSlo (or hSlo) expressed in Xenopus laevis oocytes. The effects of these structurally novel maxi-K channel openers on bladder contractile function were studied in vitro using isolated rat bladder strips pre-contracted with carbachol. Several 1,3-diaryl 1,2,4-(4H)-triazol-5-one derivatives were found to be potent smooth muscle relaxants but this activity did not completely correlate with maxi-K channel opening.
- Hewawasam, Piyasena,Erway, Matthew,Thalody, George,Weiner, Harvey,Boissard, Christopher G.,Gribkoff, Valentin K.,Meanwell, Nicholas A.,Lodge, Nicholas,Starrett, Jr, John E.
-
p. 1117 - 1120
(2007/10/03)
-