38876-67-4Relevant articles and documents
Zn-Catalyzed Enantio- and Diastereoselective Formal [4 + 2] Cycloaddition Involving Two Electron-Deficient Partners: Asymmetric Synthesis of Piperidines from 1-Azadienes and Nitro-Alkenes
Chu, John C. K.,Dalton, Derek M.,Rovis, Tomislav
, p. 4445 - 4452 (2015/04/14)
We report a catalytic asymmetric synthesis of piperidines through [4 + 2] cycloaddition of 1-azadienes and nitro-alkenes. The reaction uses earth abundant Zn as catalyst and is highly diastereo- and regioselective. A novel BOPA ligand (F-BOPA) confers high reactivity and enantioselectivity in the process. The presence of ortho substitution on the arenes adjacent to the bis(oxazolines) was found to be particularly impactful, due to limiting the undesired coordination of 1-azadiene to the Lewis acid and thus allowing the reaction to be carried out at lower temperature. A series of secondary kinetic isotope effect studies using a range of ligands implicates a stepwise mechanism for the transformation, involving an initial Michael-type addition of the imine to the nitro-alkene followed by a cyclization event. The stepwise mechanism obviates the electronic requirement inherent to a concerted mechanism, explaining the successful cycloaddition between two electron-deficient partners. (Chemical Equation Presented).
NITROGENOUS FUSED-RING DERIVATIVES, MEDICINAL COMPOSITIONS CONTAINING THE DERIVATIVES, AND USE THEREOF AS DRUGS
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Page/Page column 34, (2010/11/24)
The present invention provides nitrogen-containing fused-ring derivatives represented by the following general formula, or pharmaceutically acceptable salts thereof, or prodrugs thereof, which exhibit an excellent inhibitory activity in human SGLT and are useful as agents for the prevention or treatment of a disease associated with hyperglycemia such as diabetes, postprandial hyperglycemia, impaired glucose tolerance, diabetic complications or obesity, in the formula R 1 represent H, an optionally substituted alkyl group, an alkenyl group, etc.; R 2 represent H, a halogen atom or an alkyl group; R 3 and R 4 represent H, OH, a halogen atom, an optionally substituted alkyl group, etc. ; Y represents CH or N; Q represents alkylene, alkenylene, etc.; ring A represents an aryl group or a heteroaryl group; G represents a group represented by the following general formula (G-1)or(G-2) (in which E 1 represents H, F or OH; and E 2 represents H, F, a methyl group, etc.), and pharmaceutical compositions comprising the same, and pharmaceutical uses thereof.
