Search results for "Pauson–Khand reaction"
showing 10 items of 11 documents
Vinyl Fluorides: Competent Olefinic Counterparts in the Intramolecular Pauson–Khand Reaction
2019
Despite the great advances achieved in the Pauson-Khand reaction and the ever-increasing demand for fluorinated compounds, the use of vinyl fluorides as olefinic counterparts in the above-mentioned transformation had been completely overlooked. Herein, we describe, for the first time, the intramolecular Pauson-Khand reaction of enynes containing a vinyl fluoride moiety.
The Fluoro-Pauson-Khand Reaction in the Synthesis of Enantioenriched Nitrogenated Bicycles Bearing a Quaternary C-F Stereogenic Center
2019
The authors are grateful to the Spanish MICINN and the AEI (CTQ2017-84249-P) for financial support, the SCSIE (Universitat de Valencia) for access to instrumental facilities, and M. ̀ R. Pedrosa (Universidad de Burgos) for providing us with MoO2Cl2. The technical and human support provided by SGIker (UPV/EHU, MINECO, GV/DJ, ERDF, and ESF) is also gratefully acknowledged. P.B. thanks the Spanish Ministry of Economy for a Ramon y Cajal contract (RyC-2016-20951). ́ The authors are also grateful to Jose Cabeza for assistance in the synthesis of certain starting materials.
ChemInform Abstract: Asymmetric Allylation/Pauson-Khand Reaction: A Simple Entry to Polycyclic Amines. Application to the Synthesis of Aminosteroid A…
2014
Asymmetric allylation of o-iodoarylsulfinylimines has been achieved in high diastereoselectivities. The thus-obtained o-iodoarylhomoallylic sulfinamides participate in a subsequent Sonogashira coupling followed by a diastereoselective intramolecular Pauson–Khand reaction. In this way, tricyclic amines showing a unique benzo-fused indenyl backbone were obtained. The methodology has been applied to the synthesis of amino steroid analogues.
Pauson-Khand reaction of internal dissymmetric trifluoromethyl alkynes. Influence of the alkene on the regioselectivity.
2014
Abstract: The scope of the Pauson-Khand reaction (PKR) of internal trifluoromethyl alkynes, previously described with norbornadiene, is expanded to norbornene and ethylene. A thorough structural analysis of the resulting PK adducts has been carried out to unveil that α-trifluoromethylcyclopentenones are preferred in all cases, independently of the electronic properties of the alkyne. The regioselectivity observed with norbornadiene and ethylene is higher than in the case of norbornene.
Synthesis and application of β-substituted Pauson-Khand adducts: trifluoromethyl as a removable steering group.
2013
The reaction between alkynes (I) and norbornadiene (II) affords the β-substituted Pauson—Khand adducts (III) as single regioisomers and the trifluoromethyl steering group can be easily removed in the presence of DBU and water.
Asymmetric Allylation/Pauson-Khand Reaction: A Simple Entry to Polycyclic Amines. Application to the Synthesis of Aminosteroid Analogues
2014
Asymmetric allylation of o-iodoarylsulfinylimines has been achieved in high diastereoselectivities. The thus-obtained o-iodoarylhomoallylic sulfinamides participate in a subsequent Sonogashira coupling followed by a diastereoselective intramolecular Pauson-Khand reaction. In this way, tricyclic amines showing a unique benzo-fused indenyl backbone were obtained. The methodology has been applied to the synthesis of amino steroid analogues.
Chiral diphosphine derivatives of alkylidyne tricobalt carbonyl clusters – A comparative study of different cobalt carbonyl (pre)catalysts for (asymm…
2016
Reaction of the tricobalt carbyne cluster [Co-3(mu(3)-CH)(CO)(9)] with chiral diphosphines of the Josiphos and Walphos families affords the new clusters [Co-3(mu(3)-CH)(CO)(7)(P-P*)] in good yield (P-P* = J004 (1), J005 (2), J007 (3), W001 (4), W003 (5)). The new alkylidyne tricobalt clusters, and the previously known [Co-3(mu(3)-CH)(CO)(7)(mu-J003)], have been tested as catalysts/catalyst precursors for intermolecular Pauson-Khand cyclization, using norbornene and phenylacetylene as substrate. The diphosphine-substituted tricobalt carbonyl clusters proved to be viable catalysts/catalyst precursors that gave products in moderate to good yields, but the enantiomeric excesses were low. When t…
Asymmetric Synthesis of Fluorinated Monoterpenic Alkaloid Derivatives from Chiral Fluoroalkyl Aldimines via the Pauson‐Khand Reaction
2020
Pauson–Khand reaction of fluorinated compounds
2020
The Pauson–Khand reaction (PKR) is one of the key methods for the construction of cyclopentenone derivatives, which can in turn undergo diverse chemical transformations to yield more complex biologically active molecules. Despite the increasing availability of fluorinated building blocks and methodologies to incorporate fluorine in compounds with biological interest, there have been few significant advances focused on the fluoro-Pauson–Khand reaction, both in the inter- and intramolecular versions. Furthermore, the use of vinyl fluorides as olefinic counterparts had been completely overlooked. In this review, we collect the advances both on the stoichiometric and catalytic intermolecular an…