31329-97-2Relevant academic research and scientific papers
Zirconocene-catalyzed cationic Diels-Alder reactions
Wipf, Peter,Xu, Wenjing
, p. 4551 - 4562 (1995)
In situ prepared Cp2ZrCl+ catalyzes the formation of dioxolenium ions from α,β-unsaturated epoxy esters. As a consequence of this activation process, acrylate, methacrylate and crotonate derivatives undergo a rapid and stereoselective cationic [4+2] cycloaddition with a wide range of dienes. Ring-extended carboxylic acid derivatives are formed in 1-7 h at 0-21°C and in 50-90% yield after saponification of the intermediate diol esters. Simple Lewis acid catalysis by Cp2ZrCl+ can be excluded on the basis of the experimental results.
BORON-BASED CYCLOADDITION CATALYSTS AND METHODS FOR THE PRODUCTION OF BIO-BASED TEREPHTHALIC ACID, ISOPHTHALIC ACID AND POLY (ETHYLENE TEREPHTHALATE)
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Paragraph 00171; 00187, (2017/04/11)
Methods for producing cycloaddition products comprising: reacting a diene with a dienophile in the presence of one or more boron-based catalysts of Formula I or Formula II are provided. In particular, the methods can be used to prepare 4-methyl-3-cyclohexene- 1-carboxylic acid and 3-methyl-3-cyclohexene-l-carboxylic acid, including bio-based versions thereof. The cycloaddition products can be advantageously used in the production of terephthalic acid and isophthalic acid, and ultimately, poly(ethylene terephthalate), and bio-based versions thereof. Formula I Formula II
Anti-MRSA agent discovery using diversity-oriented synthesis
Thomas, Gemma L.,Spandl, Richard J.,Glansdorp, Freija G.,Welch, Martin,Bender, Andreas,Cockfield, Joshua,Lindsay, Jodi A.,Bryant, Clare,Brown, Derek F. J.,Loiseleur, Olivier,Rudyk, Helene,Ladlow, Mark,Spring, David R.
supporting information; experimental part, p. 2808 - 2812 (2009/02/06)
Beating the superbugs: Diversity-oriented synthesis using a solid-supported phosphonate unit to synthesize 242 drug-like compounds based on 18 natural-productlike scaffolds led to the discovery of gemmacin (see scheme). This new structural class of antibiotic is active towards methicillin-resistant Staphylococcus aureus (MRSA). (Chemical Equation Presented).
SuperQuat 5,5-dimethyl-4-iso-propyloxazolidin-2-one as a mimic of Evans 4-tert-butyloxazolidin-2-one
Bull, Steven D.,Davies, Stephen G.,Garner, A. Christopher,Kruchinin, Dennis,Key, Min-Suk,Roberts, Paul M.,Savory, Edward D.,Smith, Andrew D.,Thomson, James E.
, p. 2945 - 2964 (2008/02/09)
The incorporation of a gem-dimethyl group at the 5-position of a chiral oxazolidinone biases the conformation of the adjacent C(4)-stereodirecting group such that the gem-dimethyl-4-iso-propyl combination mimics a C(4)-tert-butyl group, providing higher levels of stereocontrol than a simple 4-iso-propyloxazolidinone. The generality of this principle is demonstrated with applications in stereoselective enolate alkylations, kinetic resolutions, Diels-Alder cycloadditions and Pd-catalysed asymmetric acetalisation reactions. The Royal Society of Chemistry 2006.
Hydrophobic effects are dominant over secondary orbital interactions for a simple Diets-Alder reaction in salt solutions
Sarma, Diganta,Kumar, Anil
, p. 2199 - 2202 (2007/10/03)
The stereoselectivity ratios for a Diels-Alder reaction between cyclopentadiene with methyl trans-crotonate carried out in salt solutions demonstrate the dominance of hydrophobic effects over secondary orbital interactions.
DMAP-promoted racemization-free deacylation of carboxthioimide adducts: Carboxthioimide as a versatile carboxy protecting group
Su, Dah-Wei,Wang, Ying-Chuan,Yan, Tu-Hsin
, p. 545 - 546 (2007/10/03)
The DMAP-promoted deacylation of carboxthioimide adducts can be directed to form either acid or various ester protecting groups with no detectable levels of epimerization.
A stereoselective biocatalytic Diels-Alder reaction
Rao,Srinivasan,Bhanumathi
, p. 5959 - 5960 (2007/10/02)
Baker's yeast catalyzes the stereoselective Diels-Alder reaction of cyclopentadiene 1 with dienophiles 2, 4 and 6. A predominant formation of exo isomer is observed in some cases.
Asymmetric Diels-Alder Reaction Using (S)-Pyroglutamic Acid Derivatives as Chiral Dienophiles
Ikota, Nobuo
, p. 2219 - 2221 (2007/10/02)
Asymmetric Diels-Alder reaction of cyclopentadiene with chiral dienophiles (3) derived from (S)-pyroglutamic acid derivatives was performed in the presence of a Lewis acid such as diethylaluminium chloride in toluene to afford the cycloadducts with high diastereoselectivity.Keywords asymmetric reaction; Diels-Alder reaction; (S)-pyroglutamic acid; chiral dienophile; diethylaluminium chloride; (2+4)cycloaddition
Addition of Methyl But-2-enedithioate to Cyclopentadiene. Cyclopentadiene as a Dienophile
Lawson, Kevin R.,Singleton, Alison,Whitham, Gordon H.
, p. 865 - 868 (2007/10/02)
Methyl but-2-enedithioate (1) acts as a heterodiene in undergoing cycloaddition to cyclopentadiene as dienophile, giving the bicyclic thiopyran (4).A possible alternative mode of cycloaddition to give the norbornenedithioester (6) followed by rearrangement to (4) is ruled out by a control experiment using (6) prepared by a different route.
REACTIONS RETRODIENIQUES-IX. SYNTHESE PAR THERMOLYSE ECLAIR ET ETUDE D'ENAMINES PRIMAIRES INSTABLES
Ripoll, J. L.,Lebrun, H.,Thuillier, A.
, p. 2497 - 2504 (2007/10/02)
Etheneamine 1 and its methyl derivatives 2-7 have been synthesized from the adducts 8-14 by a retro-Diels-Alder reaction under flash thermolytic conditions.The primary enamines 1-4 have been identified (IR, (1)H and (13)C NMR in a pure state at -80 deg C; at the same temperature, the enamines 5-7, less stable, are already accompanied by their tautomeric imines 33 or 34.When warmed up to room temperature, the enamines 1-7 lead, following to their substitution, either to nitrogen heterocycles (30, 42) or to acyclic azadienes (35-37, 39, 40).
