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2- phosphorane

Wittig reaction The reaction between an alkyl-idene phosphorane, C = PR3 and an... [Pg.426]

Surprisingly carbonyl-substituted carbanions of phosphonates, in which the negative charge is delocalized over two oxygen atoms, are much more nucleophilic than the corresponding phosphoranes. This effea has first been observed by Homer, and has often been utilized in the synthesis of acylated olefins (R.D. Clark, 1975). [Pg.29]

In a similar way the use of the 2-methyl-3-isothiocyanato-4-thiocyanato-hept-3-ene (252) prepared from thiocyanogen and the oxoal-kylene phosphorane (251) yields the 2-anilino-4-propyl-5-isopropyl-thiazole (253) by condensation with aniline (Scheme 128). [Pg.299]

Synthesis. The first hiUy alkyl/aryl-substituted polymers were reported in 1980 via a condensation—polymeri2ation route. The method involves, first, the synthesis of organophosphine-containing alkyl or aryl substituents, followed by the ready oxidation of the phosphine to a phosphorane with leaving groups suitable for a 1,2-elimination reaction. This phosphorane is then thermally condensed to polymers in which all phosphoms atoms bear alkyl or aryl substituents. This condensation synthesis is depicted in Eigure 2 (5—7,64). [Pg.258]

The racemic form of the unsubstituted nucleus (1, X = CH2) was synthesized by several groups (32—34) prior to the disclosure of the natural material. One reaction path involved an azetidinone (21) where R = CH2OH or CH=CH2 converted to the corresponding phosphorane (22) where R = o-NO.-C,H, when R = CH.OH and R = COCH, when R=CH=CH.. [Pg.6]

Extension of the Phosphorane Route. Ample evidence of the versatihty of the phosphorane synthesis strategy is provided by the proliferation of penems that followed. Nucleophilic displacement of the acetate function of the acetoxy-azetidinone (51, R = OCOCH ) [28562-53-0] (86) provided azetidinones where R = SCOCH, SCSSC2H, and SCSOC2H, which on elaboration gave the penems (52, R = CH ) (87), (52, R = SC2H ) (88), (52, R = 0C2H ) (89). Similar treatment of 3-substituted (or disubstituted) acetoxyazetidinones allowed the synthesis of a number of 2-substituted- 6-alkyl-and 6,6-dialkylpenems (90). [Pg.9]

A variety of 1-azirines are available (40-90%) from the thermally induced extrusion (>100 °C) of triphenylphosphine oxide from oxazaphospholines (388) (or their acyclic betaine equivalents), which are accessible through 1,3-dipolar cycloaddition of nitrile oxides (389) to alkylidenephosphoranes (390) (66AG(E)1039). Frequently, the isomeric ketenimines (391) are isolated as by-products. The presence of electron withdrawing functionality in either or both of the addition components can influence the course of the reaction. For example, addition of benzonitrile oxide to the phosphorane ester (390 = C02Et) at... [Pg.89]

Phosphonium hexafluorophosphate, benzotriazolyl-N-hydroxytris(dimethylamino)-in peptide synthesis, 5, 728 Phosphonium salts chromene synthesis from, 3, 753 reactions, 1, 531 Phosphonium salts, vinyl-in pyrrole synthesis, 4, 343 Phosphonium ylides in heterocyclic synthesis, 5, 165 Phosphoramide, triethylene-as pharmaceutical, 1, 157 Phosphoramide, triethylenethio-as pharmaceutical, 1, 157 Phosphorane, pentaphenyl-synthesis, 1, 532 Phosphoranes, 1, 527-537 Berry pseudorotation, 1, 529 bonding, 1, 528... [Pg.743]

Polythia six-membered ring systems, 3, 1039-1086 Polythiazides as diuretic, 1, 174 Polythiiranes, 7, 182 Polytopal rearrangements phosphoranes, 1, 529-530 rules, 1, 530 Polyurethanes curing agents... [Pg.748]

Olmethyl-3-methoxy-3-phenyl-l-(2,6-dimethyiphenyi)-lH>lmldazo(l,2 b) pyrrazol-2(3H)-one (3) Phosphorane 2 (t 48 g 3 mmol) and 2 6 dimethylphenylisocya-nate 3 (0 59 g 4 mmol) in PhMe (30 mL) was heated under reflux with stimng for 16 h (TLC EtOAc hexane I 6) Evaporation and column chromatography (silica gel EtOAc/hexane 1 6) afforded crude 4 Recrysiallization from EtaO petroleum ether gave 0 930 g (66%) mp 126 5 130"C... [Pg.341]

Olefin synthesis Irom phosphorane ylides (e g 3) with aldehydes or ketones cis olelins predominate in aliphatic systems trans m coniugated olefins... [Pg.421]

Ethyl (triphenylphosphoranylidene)acetate is available from FIuka AG and Trldom Chemical Inc. under the name (ethoxycarbonylmethylene)triphenyl-phosphorane and from Aldrich Chemical Company, Inc. under the name (carbethoxymethylene)triphenylphosphorane. The reagent may be prepared from triphenyl phosphine and ethyl bromoacetate by the following procedure. ... [Pg.203]

The acylation of Wittig reagents provides the most convenient means for the preparation of allenes substituted with various electron-withdrawing substituents. The preparation of o-allenic esters has been accomplished by the reaction of resonance-stabilized phosphoranes with isolable ketenes and ketene itself and with acid chlorides in the presence of a second equivalent of the phosphorane. The disadvantages of the first method are the necessity of preparing the ketene and the fact that the highly reactive mono-substituted ketenes evidently cannot be used. The second method fails when the a-carbon... [Pg.205]

The reaction times varied from 10 min to 18 hr. A=the correspondi ng phosphonii salt was used with the addition of two moles of triethyl amine. B=the corresponding phosphorane was used with the addition of one mole of triethylamine. [Pg.207]


See other pages where 2- phosphorane is mentioned: [Pg.308]    [Pg.308]    [Pg.407]    [Pg.28]    [Pg.29]    [Pg.31]    [Pg.121]    [Pg.730]    [Pg.731]    [Pg.733]    [Pg.36]    [Pg.6]    [Pg.9]    [Pg.10]    [Pg.10]    [Pg.11]    [Pg.11]    [Pg.42]    [Pg.335]    [Pg.41]    [Pg.41]    [Pg.41]    [Pg.41]    [Pg.41]    [Pg.41]    [Pg.41]    [Pg.42]    [Pg.619]    [Pg.744]    [Pg.12]    [Pg.202]    [Pg.204]    [Pg.205]    [Pg.206]   
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Acyclic Phosphoranes

Aldehydes with phosphoranes

Alkene triaryl phosphorane

Alkylidene complexes phosphoranes

Alkylidene transfer from phosphoranes

Aminobis phosphorane

Anhydrides with phosphoranes

Bicyclic and Tricyclic Phosphoranes

Bicyclic phosphoranes

Bicyclic phosphoranes, synthesis

Bicyclic, Tricyclic and Tetracyclic Phosphoranes

Bis phosphoran

Bis phosphorane

Bis phosphoranes

Bis-methylene-phosphorane

Bromine with phosphoranes

Carbenes phosphorane complex

Carbon dioxide with phosphoranes

Chiral phosphoranes

Chiral phosphoranes synthesis

Condensation with phosphoranes

Cyclic phosphorane intermediate

Cyclic phosphoranes conformation

Cyclic phosphoranes examples

Cyclic phosphoranes stability

Diphenyl phosphorane

Ethoxycarbonylmethylene phosphorane

From phosphoranes

Glucose reaction with phosphorane

Halogenotrifluoromethyl-phosphines and -phosphoranes

Imines with phosphoranes

Imino phosphoranes

Interconversion of Mono and Bicyclic Phosphoranes

Isocyanates with phosphoranes

Isomerism phosphonium salt-phosphorane

Isopropylidene phosphorane

Ketenes with phosphoranes

Lactones with phosphoranes

Lower symmetry than expected in some phosphines and phosphoranes

Methylene phosphorane

Methylene phosphoranes

Methylene phosphoranes rearrangements

Mixed Phosphoranes

Monocyclic Phosphoranes

N-Acylalkoxylamines a-Acylalkylidene)phosphoranes

Nucleophile phosphoranes

Nucleophiles phosphoranes

P-Ylides (Phosphoranes)

Pentafluoro phosphorane

Phosphate ester hydrolysis phosphorane intermediates

Phosphines and phosphoranes

Phosphonium salt-phosphorane equilibria

Phosphoran

Phosphoran

Phosphorane activated

Phosphorane cage compounds

Phosphorane chemical shifts

Phosphorane dianion

Phosphorane dihalides, triarylimidoyl halide synthesis

Phosphorane ester

Phosphorane halides, tetraarylimidoyl halide synthesis

Phosphorane intermediate

Phosphorane methylenetriphenyl

Phosphorane preparation

Phosphorane reaction with carbohydrates

Phosphorane reactions, electronic effects

Phosphorane sugar, synthesis

Phosphorane trimethyl[ methylene

Phosphorane with carbohydrates

Phosphorane ylid rearrangement

Phosphorane, N-aryliminovinylidenetriphenyldimerization

Phosphorane, a-trimethylsilylalkylidenea-trimethylsilylphosphonium salt synthesis

Phosphorane, acetylmethylenetriphenylreactions with organolithium compounds

Phosphorane, alkylidenetrialkyllithium salt complexes

Phosphorane, alkylidenetriphenylalkylation alkynyl-substituted

Phosphorane, alkylidenetriphenylalkylation formylation

Phosphorane, alkylidenetriphenylalkylation intramolecular

Phosphorane, alkylidenetriphenylalkylation synthesis

Phosphorane, allylidenetriphenylreactions with chloro compounds

Phosphorane, allylidenetriphenylreactions with chloro compounds synthesis

Phosphorane, bis methylenetriphenylsynthesis

Phosphorane, bis methylenetriphenylsynthesis via carbenoid method

Phosphorane, bisalkylideneexocyclic synthesis

Phosphorane, carbene complex

Phosphorane, dibromotriphenyl

Phosphorane, dibromotriphenylacid halide synthesis

Phosphorane, dibromotriphenylacid halide synthesis alkyl alcohols

Phosphorane, dibromotriphenylacid halide synthesis bromination

Phosphorane, dichloromethylene

Phosphorane, dichlorotriphenyl

Phosphorane, dichlorotriphenylacid halide synthesis

Phosphorane, dichlorotriphenylacid halide synthesis reaction with neopentyl alcohol

Phosphorane, diethoxythiovinylidenetriphenylreactions with heteroallenes

Phosphorane, diethoxytriphenylreactions with 2-amino alcohols

Phosphorane, diethoxyvinylidenetriphenylreactions with alcohols

Phosphorane, dihalotriorganoreaction with activated methylene compounds

Phosphorane, ethoxyvinylidenetriphenylreactions with alcohols

Phosphorane, ethylidenetriphenylWittig reaction

Phosphorane, fluoro aliphatic and diphenyltrifluoro

Phosphorane, fluoro aliphatic and phenyltetrafluoro

Phosphorane, fluoro aliphatic and tri-n-butyldifluoro

Phosphorane, formylMichael addition

Phosphorane, iminovinylidenereactions with acidic compounds

Phosphorane, iminovinylidenereactions with acidic compounds synthesis

Phosphorane, iminovinylidenetriphenylphosphonium ylide synthesis

Phosphorane, iminovinylidenetriphenylphosphonium ylide synthesis cycloaddition

Phosphorane, iminovinylidenetriphenylphosphonium ylide synthesis reactions with alkyl halides

Phosphorane, methylene-, derivatives

Phosphorane, oxovinylidenephosphonium ylide synthesis

Phosphorane, oxovinylidenephosphonium ylide synthesis reactions with acidic compounds

Phosphorane, oxovinylidenetriphenylreactions with alkyl halides

Phosphorane, oxovinylidenetriphenylreactions with alkyl halides cycloaddition

Phosphorane, oxovinylidenetriphenylreactions with alkyl halides synthesis

Phosphorane, pentachloro

Phosphorane, pentachloro chloride

Phosphorane, phenylfluorofluorination alkyl alcohols

Phosphorane, thermolysis

Phosphorane, thioxovinylidenereactions with acidic compounds

Phosphorane, thioxovinylidenereactions with acidic compounds synthesis

Phosphorane, thioxovinylidenetriphenylreaction with heteroallenes

Phosphorane, thioxovinylidenetriphenylreaction with heteroallenes cycloaddition

Phosphorane, thioxovinylidenetriphenylreaction with heteroallenes synthesis

Phosphorane, triarylphotographic stabilizer

Phosphorane, triphenyl

Phosphorane, vinylidenecycloaddition phosphonium ylide synthesis

Phosphorane, vinylidenecycloaddition synthesis

Phosphorane-phosphane

Phosphorane-ylide equilibria

Phosphoranes Carbodiphosphoranes

Phosphoranes Fluorophosphoranes

Phosphoranes Hydroxyphosphoranes

Phosphoranes Phosphorescence

Phosphoranes Stabilised

Phosphoranes Subject

Phosphoranes Thioxophosphoranes

Phosphoranes Triphenylphosphoranes

Phosphoranes Vinylphosphoranes

Phosphoranes alkylidenephosphoranes

Phosphoranes as intermediates

Phosphoranes bond angles

Phosphoranes bond lengths

Phosphoranes bonding

Phosphoranes compounds

Phosphoranes conductivity

Phosphoranes containing a P-H Bond

Phosphoranes cumulated

Phosphoranes electrochemistry

Phosphoranes elongated

Phosphoranes formation

Phosphoranes isomerism

Phosphoranes metal complexes

Phosphoranes of Special Interest

Phosphoranes orthoester

Phosphoranes reaction

Phosphoranes reactions with

Phosphoranes reactions with lactones

Phosphoranes special

Phosphoranes synthesis

Phosphoranes with double bonds

Phosphoranes with miscellaneous

Phosphoranes,

Phosphoranes, acylcharge-directed conjugate addition

Phosphoranes, alkylidene

Phosphoranes, alkylidene transfer

Phosphoranes, cleavage

Phosphoranes, cleavage ethers

Phosphoranes, cyclic

Phosphoranes, hydrazones

Phosphoranes, iminoamidine synthesis

Phosphoranes, oxy

Phosphoranes, reaction with azide

Phosphoranes, reduction

Phosphoranylidene Phosphoranes

Preparation of Phosphoranes by Exchange Methods

Reaction Paths with Phosphoranes

Reactions from phosphoranes

Reactions of Phosphoranes

Ring Containing Phosphoranes

Spirobicyclic phosphoranes

Spirocyclic phosphoranes

Sugar phosphoranes

The chemistry of organophosphorus compounds, Volume 3, Phosphonium salts, ylides and phosphoranes Edited by Frank R. Hartley

The chemistry’ of organophosphorus compounds, Volume 3, Phosphonium salts, ylides and phosphoranes

Three-, Four-, and Five-membered-ring Phosphoranes

Tricyclic phosphoranes

Uses of Phosphoranes in Organic Synthesis

With spirobicyclic phosphoranes

Wittig reaction phosphorane

Ylides Phosphoranes

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