26429-98-1

Upstream product

• 110-82-7 cyclohexane 
• 922-67-8 propynoic acid methyl ester 
• 5927-18-4 trimethyl phosphonoacetate 
• 2043-61-0 cyclohexanecarbaldehyde 
• 88738-78-7 bis-(2,2,2-trifluoroethyl)(methoxycarbonylmethyl)phosphonate 
• 21204-67-1 methyl (triphenylphosphoranylidene)acetate 
• 100-49-2 cyclohexylmethyl alcohol 
• 24371-94-6 cyclohexylmercury chloride 
• 1067-74-9 Methyl diethylphosphonoacetate 
• 319488-96-5 C₁₇H₁₈NO₄P 
• 6213-88-3 (E)-methyl 3-iodoacrylate 
• 6214-23-9 methyl (2Z)-3-iodoprop-2-enoate 
• 3510-44-9 methyl cis-2-chloroacrylate 

Relevant academic research and scientific papers

P[N(i-Bu)CH2CH2]3N: Nonionic Lewis base for promoting the room-temperature synthesis of α,β-unsaturated esters, fluorides, ketones, and nitriles using Wadsworth - Emmons phosphonates

The bicyclic triaminophosphine P(RNCH2CH2) 3N (R = i-Bu, 1c) serves as an effective promoter for the room-temperature stereoselective synthesis of α,β-unsaturated esters, fluorides, and nitriles from a wide array of aromatic, aliphatic, heterocyclic, and cyclic aldehydes and ketones, using a range of Wadsworth-Emmons (WE) phosphonates. Among the analogues of 1c [R = Me (1a), i-Pr (1b), Bn (1d)], 1a and 1b performed well, although longer reaction times were involved, and 1d led to poorer yields than 1c. Functionalities such as cyano, chloro, bromo, methoxy, amino, ester, and nitro were well tolerated. We were able to isolate and characterize (by X-ray means; see above) the reactive WE intermediate species formed from 2b and 1c.

Highly (E)-selective wadsworth-emmons reactions promoted by methylmagnesium bromide

(Chemical Equation Presented) An experimentally simple protocol for the very highly (E)-selective Wadsworth-Emmons reaction [(E):(Z) selectivities in excess of 180:1 in some cases] of a range of straight-chain and branched aliphatic, substituted aromatic, and base-sensitive aldehydes via reaction with an alkyl diethylphosphonoacetate and MeMgBr is reported.

The photomediated reaction of alkynes with cycloalkanes

In the presence of a photomediator such as benzophenone, alkynes with electron-withdrawing groups react with cycloalkanes to give vinyl cycloalkanes. The reaction involves the regiospecific addition of a photochemically generated cycloalkyl radical to the β-carbon of the alkyne. The stereochemical outcome of the reaction depends on the nature of the photomediator and alkyne used. The Royal Society of Chemistry 2006.

Diastereoselective method of preparing olefins by means of the horner-wadsworthemmons reaction, comprising the addition of a tris-(polyoxaalkyl)-amine sequestering agent

The invention relates to a process for the diastereoselective preparation of olefins via the Homer-Wadsworth-Emmons reaction, which consists in reacting at low temperature a phosphonate with a carbonyl derivative in the presence of a base in a suitable solvent, characterized in that a tris(polyoxaalkyl)amine sequestering reagent of formula (I): N—[CHR1—CHR2—O—(CHR3—CHR4—O)n—R5]3 (I), wherein: n is an integer between 0 and 10; R1, R2, R3 and R4 may be identical or different, and represent a hydrogen atom or an alkyl radical containing from 1 to 4 carbon atoms; R5 represents a hydrogen atom, an alkyl or cycloalkyl radical containing up to 12 carbon atoms, a phenyl radical or a radical of formula —CμH2μ-Φ, or CmH2m+1-Φ-, with m being an integer between 1 and 12 and Φ being a phenyl radical; is added in an amount that is sufficient to increase the diastereoselectivity of the olefin.

A convenient one-pot PCC oxidation-Wittig reaction of alcohols

A simple one-pot process for the PCC oxidation of alcohols followed by in situ trapping of the aldehyde with a Wittig reagent is described.

Excess sodium ions improve Z selectivity in Horner-Wadsworth-Emmons olefinations with the Ando phosphonate

New, improved conditions for Z selective Horner-Wadsworth-Emmons olefinations with Ando's bis(o-methylphenyl)phosphonates are reported. A combination of NaH and NaI affords Z olefins in up to >99:1 selectivity and good yields.

Catalytic asymmetric cyclopropanation of allylic alcohols with titanium-TADDOLate: Scope of the cyclopropanation reaction

A substoichiometric amount of titanium-TADDOLate complex was effective at catalyzing the cyclopropanation reaction of allylic alcohols in the presence 1 equiv of bis(iodomethyl) zinc. After initial optimization of the catalyst structure, excellent yields and enantiomeric ratios were obtained for 3-aryl- or 3-heteroaryl-substituted allylic alcohols (up to 97:3). Alkyl-substituted allylic alcohols gave modest yields and enantiomeric ratios (up to 87:13) but these compare favorably with those observed with other substoichiometric chiral ligands. The full synthetic scope of the reaction is presented in this paper.

Stereocontrol of the Horner-Wadsworth-Emmons Reaction: Application to the Synthesis of HIV-1 Protease Inhibitors

A systematic study on the Horner-Wadsworth-Emmons (HWE) reaction has shown that ethyl diphenylphosphonoacetate and methyl diphenylphosphonoacetate give a high excess of (Z)-alkenes. These reaction conditions were then used to prepare (Z)-ethyl-5-phenylpent-2-enoate, the corresponding (E)-isomer being prepared by standard Wittig chemistry. Reduction of each allylic ester, with diisobutylaluminium hydride (DIBAL), gave the allylic alcohols (15) and (19), respectively. Epoxidation of (15) and (19), under Sharpless conditions, gave separate samples of all four stereoisomers of 2,3-epoxy-5-phenylpentan-1-ol. Esterification of each isomer with Cbz-valine, under Mitsunobu conditions, provided (9)-(12) which were assayed against HIV protease. The cis series (9)-(10) proved to be significantly more potent than the trans (11)-12) and, within each of these series, the isomers derived from L-diisopropyltartrate [(9) and (11)] were the most active.

Olefination reactions through phosphazenes

The first synthesis of di-, tri- and tetrasubstituted alkenes through reaction of lithium P-diphenyl(alkyl)(N-carboxymethyl)phosphazenes with aldehydes and ketones is reported.

Wittig reactions in the presence of silica gel

Wittig reactions, of stable phosphorous ylids, when carried out in presence of silica gel, in hexane, provide a fast, efficient and simple method to obtain α:β unsaturated compounds in high yields and high purity.