Synthesis of vinyl ethers of furfurylideneaminophenols

The reaction of furfural and its homologs with vinyl and ethyl ethers of o-, m-, and p-aminophenols at room temperature without the addition of any catalyst whatever leads to the amine-aldehyde condensation with the formation of the corresponding ethers of furfurylidene-aminophenols. The structure of the latter has been shown by hydrolysis, hydrogenation, and independent synthesis.     

Synthesis of vinyl ethers of furfurylideneaminophenols

The reaction of furfural and its homologs with vinyl and ethyl ethers of o-, m-, and p-aminophenols at room temperature without the addition of any catalyst whatever leads to the amine-aldehyde condensation with the formation of the corresponding ethers of furfurylidene-aminophenols. The structure of the latter has been shown by hydrolysis, hydrogenation, and independent synthesis.     

Synthesis and conformational analysis of furfuryl vinyl ethers

Five furfuryl vinyl ethers were synthesized from the corresponding furfuryl alcohols and acetylene at high and atmospheric pressures in superbasic medium KOH-DMSO. On the example of 2-vinyloxymethylfuran and 2-vinyloxymethyltetrahydrofuran, their conformational structures have been studied by quantum chemistry methods, NMR and IR spectroscopy. In particular, from the results of the quantum-chemical calculations, as well as on the basis of experimental measurement and nonempirical calculations of the high level spin-spin coupling constants ¹³C-¹³C and ¹³C-¹H, a conclusion has been drawn on the s-cis-orientation of the vinyl groups with respect to the C_α-O bond in the predominant conformers of 2-vinyloxymethylfuran and 2-vinyloxymethyltetrahydrofuran.     

Synthesis and polymerization of vinyl esters and vinyl ethers having bulky substituents

In order to clarify the effect of bulky substituents on the stereoregulation of vinyl monomers, vinyl-1-adamantanecarboxylate and vinyl 1-adamantyl ether were synthesized and polymerized by radical and cationic mechanisms, respectively. As open-chain models of the adamantyl group, vinyl trialkylacetate (alkyl = ethyl, n-propyl, and n-butyl) and vinyl tri-n-propylcarbinyl ether were also synthesized and polymerized. The adamantly group in the vinyl ester favored syndiotactic propagation in a manner similar to the trimethylcarbinyl group. Higher homologs of tri-n-alkylcarbinyl group showed higher syndiotacticity but this effect was saturated in higher members of the series. The effect of the adamantyl group in vinyl ether was similar to that of the tert-butyl group, leading to high isotacticity on cationic polymerizations in nonpolar solvents and to atactic polymers in polar solvents, but the tri-n-propylcarbinyl group was found unique in leading to what was assumed to be a heterotactic polymer. Polymers with the adamantyl group showed much higher softening points than polymers of the corresponding open-chain groups.     

Synthesis of low molecular weight perfluoro oxymethylene vinyl ethers

Perfluoro oxymethylene vinyl ethers have been formed by a multi-step synthesis. The key intermediates are low molecular weight perfluoropolyether (PFPE) fluoroformates CF₃O(CF₂O)_nCOF (I) n=1-6 obtained from the photo-oxidation of perfluoro propene (HFP) in perfluorohexane. Under certain conditions the light-mediated fluorination of PFPE fluoroformates (I) gives PFPE hypofluorites CF₃O(CF₂O)_nCF₂OF (II), which can be added to sym dichlorodifluoroethene to form the dichloro adduct CF₃O(CF₂O)_nCF₂OCFClCF₂Cl (III) which, after dechlorination, gives the desired vinyl ethers CF₃O(CF₂O)_nCF₂OCFCF₂ (IV). Every reaction step has to be properly controlled as far as the reaction variables are concerned. A mechanistic scheme is presented that is consistent with the observed experimental data.     

Thermodynamics of vinyl ethers—XV : Halogen-containing vinyl ethers

Thermodynamics of geometrical and prototropic isomerization reactions on some halogen-containing vinyl ethers of the types ROCH–CHX (X = Cl, Br), ROC(CH₂X)CH₂ (X = F, Cl, Br), and ROC(CHMeCl)CH₂ (R = Me, Et, Et₂CH) have been studied. In ROCH_αCH_βX the cis (or Z) isomer is thermodynamically the more stable isomer, the higher stability of the Z isomer being due to its lower enthalpy. The relative stability of the E and Z forms is, however, reversed if the α H atom is replaced by a Me group. In systems like OCCX the double-bond stabilizing ability of the halogen atom decreases in the order Cl > Br > F, in contrast to the case in haloalkenes, where the corresponding order is F > Cl > Br.     

Synthesis of sugar-based ethenyl ethers through a vinyl bis-sulfone methodology

The recently devised route to ethenyl ethers—i.e. 1,2-bis(phenylsulfonyl)ethylene (BPSE)-mediated conversion of alcohols into β-alkoxyvinyl sulfones followed by reductive desulfonylation—has been applied in the carbohydrate field to the synthesis of a number of vinyl-functionalised monosaccharides, a number of which had not been prepared via alternative routes.     

Cyclization of vinyl ethers derived from amino alcohols

Cyclization of vinyl ethers derived from linear and cyclic α- and β-amino alcohols, catalyzed by mercury(II) acetate gave 2-methyloxazolidines and 2-methylperhydro-1,3-oxazines in 37–94% yield.     

Synthesis of iron chalcogenides from single source precursors

In this review article the synthesis of iron chalcogenides using single source precursors is discussed. The effect on morphology and phase of iron chalcogenides formed is studied by varying single source precursors, reaction temperature, reaction time, surfactants and their concentration. Copyright © 2016 John Wiley & Sons, Ltd.     

A Stereoselective synthesis of vinyl ethers from α-alkoxyaldehydes

A general, stereoselective approach to vinyl ethers from α-alkoxyaldehydes is described which features a stereocontrolled tri- n-butylstannyl addition/elimination sequence.