123098-25-9

Upstream product

• 26631-69-6 ethyl (E)-2,3-dibromopropenoate 
• 93296-09-4 4-methoxyphenylzinc chloride 
• 123-11-5 4-methoxy-benzaldehyde 
• 16139-79-0 ethyl diphenylphosphonoacetate 
• 1187-08-2 2-bromomalonic acid monoethyl ester 
• 803-14-5 ethyl 2-bromo-2-(triphenylphosphoranylidene)acetate 
• 28845-75-2 triethyl 2,2-dibromophosphonoacetate 
• 623-47-2 propynoic acid ethyl ester 

Relevant academic research and scientific papers

Highly Regioselective Palladium-Mediated Synthesis of Stereoisomerically Pure (Z)- and (E)-Alkyl 2-Bromo-3-(hetero)arylpropenoates

Stereoisomerically pure (Z)- and (E)-alkyl 2-bromo-3-(hetero)arylpropenoates, (Z)- and (E)-2, have been efficiently and selectively prepared by Pd(0)-mediated cross-coupling reaction between (hetero)arylzinc halides, 5, and easily available (Z)- and (E)-a

Synthesis of α,β-Disubstituted Acrylates via Galat Reaction

Galat reactions between aldehydes and substituted malonic acids half oxyester were found to be efficiently catalyzed by morpholine in refluxing toluene. This transformation allows the stereoselective synthesis of diverse α,β-disubstituted acrylates in moderate to good yields. This method constitutes an attractive alternative to existing methods in terms of scope and eco-compatibility.

Titanocene(III) chloride mediated radical induced addition-elimination route to the synthesis of racemic and optically active trisubstituted tetrahydrofurans: Formal synthesis of magnofargesin and 7’-epimagnofargesin

Titanocene(III) Chloride mediated radical induced synthesis of 4-benzylidene substituted tetrahydrofuran, a typical lignan skeleton, has been accomplished in good yield through addition-elimination route in racemic as well as in optically active forms. The method has been applied to the synthesis of furano lignans, magnofargesin (1) and 7’-epimagnofargesin (2) in optically active forms.

Simple and efficient copper-catalyzed approach to 2,4-disubstituted imidazolones

(Figure Presented) Some imidazolone derivatives are biological and pharmaceutical active molecules and the chromophores of the fluorescent proteins. In this communication, a simple and efficient approach to 4-arylidene-2-alkyl-4,5-dihydro-1H-imidazol-5-ones (2,4-disubstituted imidazolones) has been developed, and the protocol uses readily available 2-bromo-3-alkylacrylic acids and amidines as the starting materials without addition of any ligand or additive. The reactions were performed under mild conditions. Therefore, the present method will be of wide application in organic chemistry and medicinal chemistry.

One-pot process in phosphonium-iodonium ylides: Nucleophilic substitution and the Wittig reaction

The nucleophilic substitution in mixed phosphonium-iodonium ylides was investigated. The iodonium group is replaced by such S-containing nucleophiles as the thiocyanate anion or thiourea, as well as by halide ions. The structure of the reaction product with the thiocyanate ion was established by X-ray diffraction. A one-pot process involving the nucleophilic substitution and the Wittig reaction was developed.

Stereoselective preparation of (E)-α-bromoacrylates from mixtures of brominated ando phosphonates

We prepared 69:31-11:89 mixtures of phosphonates 6b and 7b containing two phenoxy substituents, a CO2Et group, and 1 or 2 bromine atoms, respectively, at the interspersed methylene group. Deprotonating 64:36 mixtures of these reagents with NaH

Versatile Transformations of α,β-Dibromoesters and Ketones in Basic Media under Microwave Irradiation

Depending on the reaction medium, α,β-dibromoesters under microwave irradiation may selectively lead to α-bromoalk-enes, to alkenes or to (E)-β-bromostyrenes. The corresponding ketones give selectively the α-bromoketones.

α-hypervalent iodine functionalized phosphonium and arsonium ylides and their tandem reaction as umpolung reagents

α-Hypervalent iodine functionalized phosphonium and arsonium ylides 2 can be used as umpolung ylides to react with nucleophiles to give α-heteroatom substituted ylides 4 in good yields. The nucleophilic substitution - Wittig tandem reaction of 2 can occur smoothly to provide an efficient method for the synthesis of (Z)-α-halo-α,β-unsaturated enoates or enones 6, stereoselectively.

ALKYL (E)- AND (Z)-2,3-DIBROMOPROPENOATES AS PRECURSORS TO 3-SUBSTITUTED ALKYL (E)- AND (Z)-2-BROMOPROPENOATES, 2,3-DISUBSTITUTED ALKYL (Z)- AND (E)-PROPENOATES AND SOME HETEROCYCLIC COMPOUNDS

3-(1-alkynyl)- and 3-aryl-substituted alkyl (Z)- and (E)-2-bromopropenoates have been stereospecifically and regioselectively synthesized by Pd-catalyzed cross-coupling reactions between 1-alkynylzinc chlorides, arylzinc chlorides or aryltributylstannanes and alkyl (Z)- and (E)-2,3-dibromopropenoates, (Z)- and (E)-2, respectively.The catalyst precursor consisting of a mixture of Pd on carbon and 3.9 equivalents of AsPh3 as well as that obtained by treatment of Pd(OAc)2 with 4 equivalents of AsPh3 in THF at 60 deg C can conveniently replace Pd(PPh3)4 in the reactions between (Z)- or (E)-2 and aryl or 1-alkynylzinc halides.On the other hand, a representative alkyl (Z)-3-alkyl-2-bromopropenoate has been prepared by reaction of a 9-alkyl-9-BBN derivative with (Z)-2a in DMF solution, in the presence of K2CO3 and a catalytic quantity of PdCl2(dppf).Some applications demonstrate the synthetic utility of 3-aryl-substituted alkyl (Z)- and (E)-propenoates, (Z)- and (E)-4.Thus, ethyl (E)-2-bromo-3-propenoate, (E)-4e, represents a direct precursor to 3-bromocoumarin, 7, and compound (Z)-8, which is obtained by acidic hydrolysis of (Z)-4e, undergoes a Pd-catalyzed intramolecular carbonylation reaction, which affords 3-ethoxycarbonylcoumarin, 9, in high yield.Moreover, treatment of compounds (Z)- and (E)-4 with organozinc or organotin derivatives, in the presence of catalytic amounts of a suitable Pd catalyst, affords, stereospecifically and in satisfactory to excellent yields, trisubstituted α,β-unsaturated esters, (E)- and (Z)-10, respectively, which cannot be easily prepared in stereoisomerically pure form by classical procedures.One of these esters, i.e. compound (E)-10c, represents a direct precursor to an isoaurone, i.e. (E)-3- benzylidenebenzofuran-2-one, (E)-11.Finally, a representative stereodefined unsymmetrically 2,3-diaryl-disubstituted alkyl propenoate has been synthesized by a one-pot procedure involving two sequential palladium-catalyzed arylations of (Z)-2a.

Carbanions phosphonate prepares par voie electrochimique: formation et reactivite vis-a-vis d'un aldehyde

Reactivity towards p-methoxybenzaldehyde (ArCHO) of electrochemically generated phosphonate carbanions has been investigated.Electrolyses were carried out at a mercury cathode in DMF and two routes to the desired carbanion have been compared: (i) Deprotonation of phosphonates of general formula (EtO)2P(O)CHYW (Y = W = Cl; Y = H, W = Cl; Y = Cl, W = CO2Et; Y = H, W = CO2Et; Y = CH3, W = CO2Et; Y = Cl, W = CH3), by the bases resulting from the electroreduction of azobenzene; addition of the carbanion formed onto the carbonyl group takes place and leads to the adduct (EtO)2P(O)CYW(Ar)O-. (ii) Two-electron reduction of halophosphonates (EtO)2P(O)CXYW (X = Cl, Y and W as above; X = Br, W = CO2Et, Y = Cl, Br, or CH3); when no H atom is present on the carbon bearing the phosphonate group (Y and W no = H), the same evolution leading to the above adduct is observed, on the contrary, when Y = H, the electrogenerated carbanion deprotonates the substrate and the resulting carbanion (EtO)2P(O)CXW reacts with the aldehyde; giving the adduct (EtO)2P(O)CXW(Ar)O-.Evolution of the intermediate adduct depends on the substituents Y (or X) and W: when W = CO2Et, whatever the nature of Y (or X), diethyl phosphate is eliminated with formation of the ethylenic ArCH=CWY (or X) (Wittig-Horner reaction); the same evolution is observed when Y = W = Cl.When W = Cl and Y = H or CH3, the final product is the phosphonate epoxyde resulting from chloride elimination (Darzens reaction).Chemo- and stereoselectivity depend only on the nature of Y and W but are independent of the mode of generation of the carbanion.Yields are limited by side-protonation reactions, which are related to the basicity of the phosphonate carbanions.Analysis of the results permits selection of the optimal electrolysis conditions for purposes of synthesis.Key words: electrosynthesis, electrogenerated bases, phosphonates, Wittig-Horner.