4683-24-3Relevant academic research and scientific papers
A simple synthesis and evaluation of the bicyclo[8.3.0] enediyne framework
Semmelhack,Jaskowski, Mark,Sarpong, Richmond,Ho, Douglas M.
, p. 4947 - 4950 (2002)
A synthesis of a simple trans fused [8.3.0]bicyclic enediyne framework was developed from cyclopentanone-trans-3,4-dicarboxylate. The rates of rearrangement of several derivatives of the framework were measured, and correlated with structural features. Preliminary studies to adjust the configuration about the ring fusion, expected to be an activation step, are discussed.
Total synthesis 2-epi-α-cedren-3-one via a cobalt-catalysed Pauson-Khand reaction
Kerr, William J.,McLaughlin, Mark,Paterson, Laura C.,Pearson, Colin M.
, p. 5062 - 5068 (2018)
Herein we target the total synthesis of 2-epi-α-cedren-3-one, a natural compound isolated from the essential oil of Juniperus thurifera. Overall, our synthetic sequence presents an optimised and robust series of chemical transformations, with prominent features including a low temperature and highly (Z)-selective Wittig olefination reaction, which is vital for the establishment of the relative stereochemistry within the final natural product, and a microwave-assisted, catalytic, intramolecular Pauson-Khand cyclisation reaction, which is used to construct the intriguing tricyclic core of the target molecule. Our optimum cyclisation protocol utilises only 20 mol% of transition metal, and delivers the complex tricyclic structure in just 10 min. Further manipulations of the annulation product culminate in the first total synthesis of the described natural target.
Use of a highly effective intramolecular Pauson-Khand cyclisation for the formal total synthesis of (±)-α- and β-cedrene by preparation of cedrone
Crawford, James J.,Kerr, William J.,McLaughlin, Mark,Morrison, Angus J.,Pauson, Peter L.,Thurston, Graeme J.
, p. 11360 - 11370 (2006)
The cedrene carbon skeleton was directly and efficiently assembled from a simple monocyclic precursor by the strategic use of a high yielding intramolecular Pauson-Khand cyclisation reaction. A small number of further synthetic manipulations provided a concise formal total synthesis of α- and β-cedrene. The cyclisation precursor was readily prepared, with a stereoselective ketone alkenylation selectively providing the olefin required for efficient access to the natural target.
Formal total synthesis of (±)-α- and β-cedrene by preparation of cedrone. Construction of the tricyclic carbon skeleton by the use of a highly efficient intramolecular Khand annulation
Kerr, William J.,McLaughlin, Mark,Morrison, Angus J.,Pauson, Peter L.
, p. 2945 - 2947 (2001)
matrix presented The cedrene carbon skeleton was rapidly assembled from a simple monocyclic precursor by the strategic use of a high yielding intramolecular Khand cyclization reaction. Further synthetic manipulations provided a concise formal total synthe
Platinum-Catalyzed α,β-Desaturation of Cyclic Ketones through Direct Metal–Enolate Formation
Chen, Ming,Dong, Guangbin
supporting information, p. 7956 - 7961 (2021/03/01)
The development of a platinum-catalyzed desaturation of cyclic ketones to their conjugated α,β-unsaturated counterparts is reported in this full article. A unique diene-platinum complex was identified to be an efficient catalyst, which enables direct metal-enolate formation. The reaction operates under mild conditions without using strong bases or acids. Good to excellent yields can be achieved for diverse and complex scaffolds. A wide range of functional groups, including those sensitive to acids, bases/nucleophiles, or palladium species, are tolerated, which represents a distinct feature from other known desaturation methods. Mechanistically, this platinum catalysis exhibits a fast and reversible α-deprotonation followed by a rate-determining β-hydrogen elimination process, which is different from the prior Pd-catalyzed desaturation method. Promising preliminary enantioselective desaturation using a chiral-diene-platinum complex has also been obtained.
Electrochemically driven desaturation of carbonyl compounds
Gnaim, Samer,Takahira, Yusuke,Wilke, Henrik R.,Yao, Zhen,Li, Jinjun,Delbrayelle, Dominique,Echeverria, Pierre-Georges,Vantourout, Julien C.,Baran, Phil S.
, p. 367 - 372 (2021/03/31)
Electrochemical techniques have long been heralded for their innate sustainability as efficient methods to achieve redox reactions. Carbonyl desaturation, as a fundamental organic oxidation, is an oft-employed transformation to unlock adjacent reactivity through the formal removal of two hydrogen atoms. To date, the most reliable methods to achieve this seemingly trivial reaction rely on transition metals (Pd or Cu) or stoichiometric reagents based on I, Br, Se or S. Here we report an operationally simple pathway to access such structures from enol silanes and phosphates using electrons as the primary reagent. This electrochemically driven desaturation exhibits a broad scope across an array of carbonyl derivatives, is easily scalable (1–100 g) and can be predictably implemented into synthetic pathways using experimentally or computationally derived NMR shifts. Systematic comparisons to state-of-the-art techniques reveal that this method can uniquely desaturate a wide array of carbonyl groups. Mechanistic interrogation suggests a radical-based reaction pathway. [Figure not available: see fulltext.]
CHEMOKINE RECEPTOR MODULATORS AND USES THEREOF
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Paragraph 1654-1655, (2018/05/03)
Disclosed herein, inter alia, are compounds and methods of use thereof for the modulation of chemokine receptor activity.
Hypervalent-Iodine-Mediated Formation of Epoxides from Carbon(sp2)-Carbon(sp3) Single Bonds
Jiang, Shan,Yan, Tai-Shan,Han, Yong-Chao,Cui, Li-Qian,Xue, Xiao-Song,Zhang, Chi
, p. 11691 - 11702 (2017/11/24)
We have developed an efficient method for direct formation of epoxide groups from carbon(sp2)-carbon(sp3) single bonds of β-keto esters; the reaction is mediated by the water-soluble hypervalent iodine(V) reagent AIBX (5-trimethylammonio-1,3-dioxo-1,3-dihydro-1λ5-benzo[d][1,2]iodoxol-1-ol anion). On the basis of the results of density functional theory calculations and experimental studies, we propose that the reaction proceeds by a two-stage mechanism involving dehydrogenation of the β-keto ester substrates and epoxidation of the resulting enone intermediates. The rate-limiting step is abstraction of the β′-C-H (calculated free energy of activation, 24.5 kcal/mol).
Visible light induced photocatalytic conversion of enamines into amides
Li, Jing,Cai, Shunyou,Chen, Jietao,Zhao, Yaohong,Wang, David Zhigang
supporting information, p. 1626 - 1628 (2014/07/08)
A series of enamines were photocatalytically cleaved to produce amide products under simple visible-light irradiation from a 45 W household light bulb. Mechanistically, the reactions appear to involve photosensitized formation of a singlet oxygen intermediate and a subsequent [2+2] cycloaddition event. Georg Thieme Verlag Stuttgart, New York.
TREATING DIABETES WITH DIPEPTIDYL PEPTIDASE-IV INHIBITORS
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, (2014/02/16)
The present invention is directed to novel substituted dihydropyrrolopyrazoles of structural Formula I which are inhibitors of the dipeptidyl peptidase-N enzyme and which are useful in the treatment or prevention of diseases in which the dipeptidyl peptid
