Alkyltriphenylphosphonium Salts Research Articles

The Simultaneous In-Situ Generation of Aldehydes and Phosphorus Ylides: A Convenient Multi-Step One-Pot Olefination Protocol

Li a-(dimethylamino)alkoxides resulting from the nucleophilic addn. of an organolithium reagent to DMF are basic enough to deprotonate alkyltriphenylphosphonium salts suspended in THF. The aldehydes, liberated by the spontaneous decompn. of the resulting a-amino alcs. (hemi-aminals), undergo a Wittig reaction with the simultaneously generated P ylides to afford olefins in excellent overall yields. This in situ method offers the unique advantage in its applicability to labile aldehydes which otherwise would become prey to (Z/E)-isomerization or self-condensation processes. [on SciFinder (R)]

A new generation of “instant ylids”: Powder mixtures of phosphonium salts and potassium hydride as storable precursors to wittig reagents

Mixing a finely pulverized alkyltriphenylphosphonium salt and potassium hydride in 1 : 1 molar ratio gives a ready-to-use powder the components of which react rapidly when tert-butyl methyl ether is added under stirring. When, in general after a few minutes, the generation of the (triphenyl-phosphonio)alkanide is complete, it can be immediately used for the Wittig olefination of a carbonyl compound. Compared to sodium amide based “instant ylids”, the new blends offer little advantage as long as simple phosphonium salts are ingredients but they extend considerably the shelf life of mixtures containing heterosubstituted derivatives such as methylthiomethyl- or picolyltriphenylphosphonium salts.

Comparisons between electron impact and fast atom bombardment mass spectra of some triphenylphosphonium and triphenylarsonium salts

The electron impact (EI) mass spectra of alkyltriphenylphosphonium and alkyltriphenylarsonium salts were compared with fast atom bombardment (FAB) mass spectra in a 3-nitrobenzyl alcohol matrix. It is clearly demonstrated that FAB is an effective ionization method compared with EI for analysis of these non-volatile and thermally labile compounds, particularly triphenylarsonium salts. In FABMS, the spectra generally show the intact cations (C+) as the base peaks, in addition to the singly charged cluster ions (C2A)+. High-resolution mass spectrometry was used to determine the elemental composition of the ions at m/z 277 for some phosphonium salts in the EI mode and the results show that the formation of (O(double bond)PPh3 − 1)+ (m/z 277) involves an oxygen rearrangement as a possible reaction pathway. B/E linked scans of the intact cations of triphenylarsonium salts generated by FABMS were studied in detail both to illustrate the dissociation pathways and to compare the reaction mechanism with that occurring for triphenylphosphonium salts.

Synthesis of 5,8‐dimethoxy‐2(1H)‐quinolinones by intramolecular Wittig reaction

AbstractThe title compounds 12, which are key intermediates for antitumoral diazaquinomycin A analogues, are obtained by intramolecular Wittig reaction of 1‐[3′,6′‐dimethoxy‐2′‐(α‐oxoacylamino)phenyl]alkyltriphenylphosphonium salts 11, which are prepared via lithiation of 2′,5′‐dimethoxy‐N‐pivaloylaniline 6. The applicability of this route to polysubstituted 2(1H)‐quinolinones 12 and 17 is examined.

Synthesis of sphingosines, 11. Convenient synthesis of phytosphingosine and sphinganine from D‐galactal and D‐arabitol

Abstract3,4,6‐Tri‐O‐benzyl‐D‐galactal (3) was directly converted into 3,4,6‐tri‐O‐benzyl‐2‐deoxy‐D‐galactose (5). Wittig reaction of 5 with alkyltriphenylphosphonium salts in the presence of n‐butyllithium as the base afforded olefins 6a, b which could be readily transformed into phytosphingosines 1a, b via different routes: (i) at first azido group introduction and then double bond and protective group removal, and azido group generation via hydrogenation; (ii) 2‐O‐mesylation, then double bond and benzyl group removal via hydrogenation, and finally nitrogen introduction; (iii) selective double bond hydrogenation, then nitrogen introduction, and finally benzyl group removal and amino group generation via hydrogenation. Wittig reaction of 5 with alkyltriphenylphosphonium salt in the presence of potassium tert‐butoxide as the base afforded diene 7a which proved to be a convenient precursor for sphinganine syntheses; thus, 2‐O‐mesylation, then double bond and benzyl group removal via hydrogenation and 1,3‐O‐acetylation, and finally nitrogen introduction and de‐O‐acetylation afforded 23a. Based on the convenient transformation of D‐arabitol into the 1,3‐O‐benzylidene derivative 25 a further phytosphingosine synthesis is outlined.

ChemInform Abstract: A Convenient Synthesis of Alkylphosphonium Salts.

Abstract The reaction of methanol and its homologs with Ph3 P in 48% aqueous hydrobromic acid provides alkyltriphenylphosphonium salts in quantitative yields.

A CONVENIENT SYNTHESIS OF ALKYLPHOSPHONIUM SALTS

Abstract The reaction of methanol and its homologs with Ph3 P in 48% aqueous hydrobromic acid provides alkyltriphenylphosphonium salts in quantitative yields.

Synthesis of alkenes by Wittig reaction using lithium 1,3-diaminopropane as a base

It has been found that the lithium 1,3-diaminopropane (X) can be used for generation of non-stabilized ylides from alkyltriphenylphosphonium salts. These ylides with aldehydes afford olefins in moderate yield with high Z-stereoselectivity. The reaction conditions were studied.

GC and HPLC analysis of alkyl triphenylphosphonium salts used in the wittig reaction

Journal of High Resolution ChromatographyVolume 11, Issue 8 p. 587-588 Short Communication GC and HPLC analysis of alkyl triphenylphosphonium salts used in the wittig reaction R. C. Harden, R. C. Harden Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this authorG. A. Harvey, G. A. Harvey Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this authorD. M. Rackham, Corresponding Author D. M. Rackham Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKLilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this author R. C. Harden, R. C. Harden Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this authorG. A. Harvey, G. A. Harvey Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this authorD. M. Rackham, Corresponding Author D. M. Rackham Lilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKLilly Research Centre Ltd, Erl Wood Manor, Windlesham, Surrey, GU20 6PH, UKSearch for more papers by this author First published: August 1988 https://doi.org/10.1002/jhrc.1240110807Citations: 1AboutPDF 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.Citing Literature Volume11, Issue8August 1988Pages 587-588 RelatedInformation

ChemInform Abstract: A Facile and Alternative Synthesis of the Quinoline Nucleus Using Thermal Cyclization of 2‐Azahexatriene System Generated from 2‐(Alkenyl)acylaniline with POCl3.

AbstractWittig reaction of the o‐nitrobenzaldehydes (I) with the alkyltriphenylphosphonium salts (II) gives the nitrostyrenes (III) which are reduced to form the o‐vinylanilines (IV).

ChemInform Abstract: Use of Triphenylphosphine Hydrobromide for the Synthesis of Alkyltriphenylphosphonium Salts.

ChemInformVolume 18, Issue 40 Organoelement Compounds ChemInform Abstract: Use of Triphenylphosphine Hydrobromide for the Synthesis of Alkyltriphenylphosphonium Salts. A. HERCOUET, A. HERCOUET Lab. Synth. Org., CNRS, 35042 Rennes, FranceSearch for more papers by this authorM. LE CORRE, M. LE CORRE Lab. Synth. Org., CNRS, 35042 Rennes, FranceSearch for more papers by this author A. HERCOUET, A. HERCOUET Lab. Synth. Org., CNRS, 35042 Rennes, FranceSearch for more papers by this authorM. LE CORRE, M. LE CORRE Lab. Synth. Org., CNRS, 35042 Rennes, FranceSearch for more papers by this author First published: October 6, 1987 https://doi.org/10.1002/chin.198740235Read 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 onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume18, Issue40October 6, 1987 RelatedInformation

UTILISATION DU BROMHYDRATE DE TRIPHÉNYLPHOSPHINE POUR LA SYNTHÈSE DE SELS D'ALKYLTRIPHÉNYLPHOSPHONIUM

Abstract Alkyltriphenylphosphonium salts can be obtained with good yields from the condensation between alkyl chlorides and triphenylphosphonium bromide.

Fast atom bombardment and laser desorption mass spectrometry for determination of alkyltriphenylphosphonium salts

Comparaison des spectres de masse et des spectres de desactivation de collision obtenus par desorption de laser et bombardement par atome rapide. Informations sur les distributions de structure et d'energie interne

Synthesis of cis and trans methyl 8- and 13-octadecenoate-d2 and d4 isomers

The synthesis of deuterium labelled, unsaturated, isomeric fatty acids was required for a series of triple-labelled feeding experiments. The preparation of the cis and trans isomers of methyl 8-octadecenoate-17, 18-d2, methyl 8-octadecenoate-13, 13, 14, 14-d4, methyl 13-octadecenoate-17, 18-d2 and methyl 13-octadecenoate-17, 17, 18, 18-d4 is described. The syntheses utilize tris (triphenylphosphine) - chlororhodium(I) catalyst for the incorporation of deuterium. The double bond is introduced by coupling a deuterated alkyl triphenylphosphonium salt with the appropriate aldehydic ester using the Wittig reaction. Optimization of conditions has increased the overall yields for these syntheses to ∼50% and the isotopic purity to >95%.