Formal Nucleophilic Substitution Research Articles

Cesium Carbonate Mediated Borylation of Aryl Iodides with Diboron in Methanol

AbstractHerein we describe the unexpected borylation of aryl iodides promoted by a Cs2CO3 and MeOH system. This formal nucleophilic boryl substitution could be applied to a wide range of functionalized aryl iodide compounds. The preliminary results indicate that this process is neither copper catalyzed nor radical mediated.

Anomalous Reactivity of Silylborane: Transition-Metal-Free Boryl Substitution of Aryl, Alkenyl, and Alkyl Halides with Silylborane/Alkoxy Base Systems

An unexpected borylation of organic halides with a silyborane in the presence of an alkoxy base has been observed. This formal nucleophilic boryl substitution can be applied to a broad range of substrates with high functional group compatibility. Even sterically hindered aryl bromides afforded the corresponding boryl compounds in high yields. Preliminary mechanistic studies indicated that this boryl substitution is promoted by neither transition-metal contamination nor a radical-mediated process.

ChemInform Abstract: Formal Nucleophilic Substitution of Bromocyclopropanes with Azoles.

AbstractThe highly diastereoselective method affords various N‐cyclopropylated heterocyles.

Formal Nucleophilic Substitution of Bromocyclopropanes with Azoles

A highly diastereoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides with azoles is described. A wide range of azoles, including pyrroles, indoles, benzimidazoles, pyrazoles, and benzotriazoles, can be efficiently employed as pronucleophiles in this transformation, providing expeditious access to N-cyclopropyl heterocycles.

Diastereoselectivity Control in Formal Nucleophilic Substitution of Bromocyclopropanes with Oxygen- and Sulfur-Based Nucleophiles

A diastereoconvergent formal nucleophilic substitution of bromocyclopropanes with oxygen- and sulfur-based nucleophiles is described. The reaction proceeds via in situ formation of a highly reactive cyclopropene intermediate and subsequent diastereoselective addition of a nucleophile across the strained C═C bond. Three alternative means of controlling the diastereoselectivity of addition have been demonstrated: (1) thermodynamically driven epimerization of enolizable carboxamides, (2) steric control by bulky substituents, and (3) directing effect of carboxamide or carboxylate functions.

Formal Nucleophilic Substitution of Bromocyclopropanes with Amides en route to Conformationally Constrained β-Amino Acid Derivatives

A chemo- and diastereoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides with secondary amides is described. This method allows for convergent and highly selective synthesis of trans-β-aminocyclopropane carboxylic acid derivatives.

Thermodynamic Control of Diastereoselectivity in the Formal Nucleophilic Substitution of Bromocyclopropanes

A new, general, and chemoselective protocol for the formal nucleophilic substitution of 2-bromocyclopropylcarboxamides is described. A wide range of alcohols and phenols can be employed as pronucleophiles in this transformation, providing expeditious access to trans-cyclopropanol ethers. A new mode of the selectivity control through a thermodynamic equilibrium is realized, alternative to the previously described steric and directing modes.

Highly Diastereoselective Formal Nucleophilic Substitution of Bromocyclopropanes

A highly diastereoselective formal nucleophilic substitution of bromocyclopropanes with oxygen- and nitrogen-based nucleophiles was demonstrated. The reaction proceeds via a base-assisted dehydrohalogenation producing a cyclopropene intermediate, which subsequently undergoes addition of a pronucleophile across the strained double bond. Very high chemoselectivity toward addition of primary and secondary alkoxides, as well as N-nucleophiles, in the presence of tert-butoxide base was observed, whereas phenoxides did not undergo addition under these reaction conditions. Facial selectivity of the addition can be efficiently controlled either by sterics or through a directing effect of an amide, carboxylate, and an o-aminomethylphenol function. Employment of tethered optically active amino alcohols as pronucleophiles allowed for efficient assembly of homochiral bicyclic compounds.

Reactions of 1,3‐Diaryl‐2‐chloropropane‐1,3‐diones with Nucleophiles − Cyanide‐Induced Retro‐Claisen−Claisen Condensation

AbstractTreatment of some 1,3‐diaryl‐2‐chloropropane‐1,3‐diones, acyclic chloro‐substituted enaminones and β‐oxo esters with nucleophiles was shown to proceed easily with the formation, at least in the first stage, of formal nucleophilic substitution products. Treatment of enaminones and β‐oxo esters with azide and cyanide ions proceeds with the preservation of the skeleton, whereas chloro‐substituted diaroylmethanes undergo retro‐Claisen−Claisen condensation reactions in the course of the reaction with cyanide. Dibenzoylchloromethane reacts with azide and cyanide ions with fragmentation of the molecule and subsequent reassembly, resulting in benzoylated benzaldehyde cyanohydrin and a 1,3‐oxathiol derivative, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Nucleophilic Substitution of Chloro‐Substituted Enaminones that are Derivatives of Imidazolidine Nitroxides − The Catalytic Effect of the Cyanide Ion

AbstractThe cyanide ion is a catalyst for reactions of nucleophiles with chloro‐substituted enaminones derived from imidazolidine nitroxides, which result in the formation of formal nucleophilic substitution products. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

Synthesis, properties, and reactions of new perfluorinated diketones

(Trifluoromethyl)trimethylsilane reacts with diacyl fluorides F(O)C(CF 2 ) n C(O)F (n=2,3) in the presence of excess KF in benzonitrile to give the cyclic alkoxides CF 3 (F)C(CF 2 ) n CO(CF 3 )O-K + . The alkoxides are formed by the formal nucleophilic substitution of CF 3 - on F(O)C-followed by a rapid cyclization of the diketone by fluoride ion to give the observed alkoxides. The free diketones CF 3 (O)C(CF 2 ) n C(O)CF 3 are isolated by a 1,4- loss of KF from the alkoxide by heating the latter under dynamic vacuum

Unusual reactivity of [6]paracyclophane toward alkyllithiums

[6]Paracyclophane underwent nucleophilic addition with n-BuLi and s-BuLi and formal nucleophilic substitution with t-BuLi

Stereoselective Connection of a C2- and a Linear Cn-Unit to a Cyclopropane by a Formal Twofold Nucleophilic Substitution

Stereoselective Connection of a C₂- and a Linear C_n-Unit to a Cyclopropane by a Formal Twofold Nucleophilic Substitution

An O .fwdarw. N acyl transfer. An important activation step for a formal nucleophilic substitution in a cyclopropane derivative

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn O .fwdarw. N acyl transfer. An important activation step for a formal nucleophilic substitution in a cyclopropane derivativeElmar Vilsmaier, Sabine Weber, and Juergen WeidnerCite this: J. Org. Chem. 1987, 52, 22, 4921–4924Publication Date (Print):October 1, 1987Publication History Published online1 May 2002Published inissue 1 October 1987https://doi.org/10.1021/jo00231a016RIGHTS & PERMISSIONSArticle Views87Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (536 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: Geometry of Formal Nucleophilic Substitution at First‐Row Heteroatoms: The Transfer of Oxygen from Nitrogen to Phosphorus.

AbstractThe conversion of (I) to (II), in which an oxygen is transferred from nitrogen to phosphorus, proceeds in toluene at 100°C in 1 h in 95% yield.

Geometry of formal nucleophilic substitution at first-row heteroatoms: the transfer of oxygen from nitrogen to phosphorus

Etude de la conversion de la N-(diphenylphosphino-2 benzyl) hydroxylamine en diphenylphosphoryl-2 benzylamine

STUDIES ON PLANT BILE PIGMENTS–6. PHOTOCHEMICALLY ASSISTED REACTION OF A‐DIHYDROBILINDIONE WITH NUCLEOPHILES AS A MODEL FOR PHYTOCHROME INTERCONVERSION

Abstract— –From the A‐dihydrobilindione 3. the pyridinium derivatives 6a, b and analogues therwf have been obtained by a formal nucleophilic substitution. The reaction is rationalized as a photochemically assisted oxidation of 3 with a subsequent regioselective addition of pyridine at C‐5. By thermolysis. 6a.b yields back the parent bilin 3, together with an oxidation product. The significance of the reaction with respect to the phytochrome interconversion is discussed.

ChemInform Abstract: A FORMAL NUCLEOPHILIC SUBSTITUTION ON BILATRIENES‐ABC

Chemischer InformationsdienstVolume 9, Issue 47 Heterocyclic Compounds ChemInform Abstract: A FORMAL NUCLEOPHILIC SUBSTITUTION ON BILATRIENES-ABC H. FALK, H. FALKSearch for more papers by this authorT. SCHLEDERER, T. SCHLEDERERSearch for more papers by this author H. FALK, H. FALKSearch for more papers by this authorT. SCHLEDERER, T. SCHLEDERERSearch for more papers by this author First published: November 21, 1978 https://doi.org/10.1002/chin.197847173Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume9, Issue47November 21, 1978 RelatedInformation

Evidence for caged intermediate species in a formal nucleophilic aromation substitution

Evidence for caged intermediate species in a formal nucleophilic aromation substitution