Bicyclic molecule

About: Bicyclic molecule is a research topic. Over the lifetime, 29587 publications have been published within this topic receiving 451252 citations. The topic is also known as: bicyclic molecule.

New strategy for the synthesis of substituted morpholines.

Abstract: A four-step synthesis of cis-3,5-disubstituted morpholines from enantiomerically pure amino alcohols is described. The key step in the synthesis is a Pd-catalyzed carboamination reaction between a substituted ethanolamine derivative and an aryl or alkenyl bromide. The morpholine products are generated as single stereoisomers in moderate to good yield. This strategy also provides access to fused bicyclic morpholines as well as 2,3- and 2,5-disubstituted products.

Design and synthesis of [2-(8,9-dioxo-2,6-diazabicyclo[5.2.0]non-1(7)-en-2-yl)-ethyl]phosphonic acid (EAA-090), a potent N-methyl-D-aspartate antagonist, via the use of 3-cyclobutene-1,2-dione as an achiral α-amino acid bioisostere

Abstract: The diazabicyclic amino acid phosphonate 15, [2-(8,9-dioxo-2,6-diazabicyclo[520]non-1(7)-en-2-yl)ethyl]phosphonic acid, was identified as a potent NMDA antagonist It contains the α-amino acid bioisostere 3,4-diamino-3-cyclobutene-1,2-dione and an additional ring for conformational rigidity Compound 15 was as potent as CGS-19755 (5) in the [3H]CPP binding assay, the stimulated [3H]TCP binding assay, and the NMDA-induced lethality model in mice A single bolus dose of compound 15, administered intravenously following permanent occlusion of middle cerebral artery (MCA) in the rat, reduced the size of infarcted tissue by 57% Structure−activity relationship (SAR) studies have indicated that the six- and eight-membered ring derivatives had diminished activity and that the two-carbon side chain length was optimum for NMDA receptor affinity Substitution on the ring was found to be counterproductive in the case of sterically demanding dimethyl groups and of no consequence in the case of an H-bonding hydroxyl

Stereoselective Preparation of Polyfunctional Cyclopentane Derivatives by Radical Nickel- or Palladium-Catalyzed Carbozincations

Abstract: The reaction of 5-hexenyl iodides with diethylzinc (2 equiv) and catalytic amounts of a PdII or NiII complex like PdCl2(dppf), PdCl2(MeCN)2, or Ni(acac)2 results in an efficient ring closure (THF, RT, 2–12 h) affording cyclopentylmethylzinc iodides, which, after transmetalation with CuCN·2LiCl, can be further functionalized by treatment with a range of electrophiles like allylic halides, acyl chlorides, enones, nitroolefins, ethyl propynoate, and alkynyl halides to yield polyfunctional cyclopentane derivatives. The ring closures occur via radical intermediates, and the stereochemistry of the products can be explained according to the rules for radical cyclizations developed by Beckwith. The preparation of several di- and trisubstituted cyclopentanes has been achieved with high stereoselectivity. Tandem ring closures can be performed to construct bicyclic or tricyclic ring systems. Cyclizations of iodo-ethylenic and acetylenic esters and ketones can be accomplished, although the high reactivity of acetylenic ketones leads to unexpected cyclization products. The synthetic utility of this method has been demonstrated by an enantioselective synthesis of (+)-methyl epijasmonate and (-)-methyl cucurbate.