Propargylation Of Aldehydes Research Articles

The reactivity of primary C 3-alcohols on gold electrodes in acid media. A comparative study based on dems data

The reaction products of propargyl alcohol (Pa), allyl alcohol (AA) and n-propanol ( n-PrOH) at different applied potentials have been investigated on Au electrodes in 0.5 M H 2SO 4. On line mass spectrometry (DEMS) reveals that CO 2 and acrolein are formed from bulk AA electro-oxidation. PA electro-oxidation produces CO 2 and propargyl aldehyde, and electroreduction yields propyne, propylene and AA. No strongly bound intermediates for AA were detected. PA forms adsorbates which give CO 2 and a C 3 hydrocarbon during electro-oxidation and electroreduction, respectively. No electrochemical activity could be detected for n-PrOH on Au.

Chlorovinylidenecarbene: generation from 3,3-dichloropropyne by interaction with potassium hydroxide under phase-transfer catalysis conditions and reactions with alkenes

Chlorination of propargyl aldehyde with PCl5 in CH2Cl2 at −20 °C in the presence of catalytic amounts of pyridine afforded dichloromethylacetylene. Reaction of the latter with powdered KOH under phase-transfer catalysis conditions gave chlorovinylidenecarbene due to γ-elimination of HCl. In the presence of alkenes the carbene undergoes addition at the double bond giving chlorovinylidenecyclopropanes in 20–45 % yields.

A new synthetic approach to enediynes related to the neocarzinostatin chromophore from α-trimethylsilyl α-allenyl carbonyl compounds

A new synthetic approach to acyl-substituted enediynes from α-trimethylsilyl α-allenyl carbonyl compounds and propargylic aldehydes is described. This process allows the rapid construction of enediyne derivatives containing vinyl halide groups, suitable for the synthesis of the neocarzinostatin chromophore.

Synthesis of Optically Active α-Alkylidene-β-hydroxy-γ-methylenebutyrolactones. Isoobtusilactones and Isomahubalactones (Isomahubanolide and Isomahubenolide)

Abstract The title compounds were prepared via stereoselective aldol reaction of α,β-unsaturated carboxylate α-anion equivalent, derived from optically active α-(arylsulfinyl)carboxylate and bromomagnesium diisopropylamide, with propargyl aldehyde as a key step.

Use of metal carbonyl complexes to achieve high enantioselectivity in the asymmetric allylboration of unsaturated aldehydes

The enantioselectivity of the asymmetric allylborations of aromatic and propargylic aldehydes is significantly enhanced by using metal carbonyl derivatives as substrates

The toxicity of acetylenic alcohols to the fathead minnow, Pimephales promelas: narcosis and proelectrophile activation.

1. The 96-h LC50 values for 16 acetylenic alcohols in the fathead minnow (Pimephales promelas) were determined using continuous-flow diluters. The measured LC50 values for seven tertiary propargylic alcohols agreed closely with the QSAR predictions based upon data for other organic non-electrolytes acting by a narcosis mechanism. 2. Four primary and four secondary propargylic alcohols were 7 to 4600 times more toxic than the respective narcotic toxicity estimated by QSAR. Metabolic activation to electrophilic alpha,beta-unsaturated propargylic aldehydes or ketones is proposed to account for the increased toxicity. 3. 3-Butyn-1-ol and 4-pentyn-2-ol, primary and secondary homopropargylic alcohols, were 320 and 160, respectively, times more toxic than predicted. In this case an activation step involving biotransformation to an allenic electrophile intermediate was proposed.

Stereoselective synthesis of (Z)-13-hexadecen-11-yn-1-yl acetate, the major component of the sex pheromone of the pine processionary moth (Thaumetopoea pityocampa)

A short and stereoselective synthesis of (Z)-13-hexadecen-1 1-yn-1-yl acetate is described. The main feature is a low-temperature Wittig reaction of a triphenylpropylphosphonium bromide with a long-chain alkylated propargyl aldehyde.

Synthesis of functional malondialdehyde derivatives from propargyl aldehyde

Synthesis of functional malondialdehyde derivatives from propargyl aldehyde

13C-C-H spin-spin coupling constants involving the formyl proton in aldehydes

The two-bond 13C-C-H coupling constants involving the formyl proton of about 40 aldehydes were measured in natural abundance. The sign of the coupling constant was found, by a decoupling technique, to be the same as the directly bonded 13C-II coupling constant. On the basis of molecular orbital theory, the two-bond coupling constants of acetaldehyde, acrolein and propargyl aldehyde were evaluated. From the calculations it was found that the main contribution to the coupling constant comes from the delocalization of the lone-pair electrons of the carbonyl oxygen atom, and the low excitation energy of these electrons. The substituent effects on, and the temperature dependence of, the two-bond coupling constant were qualitatively elucidated along these lines.

(118)プロパルギルアルコールを原料とする2-アミノピリミジンの合成に関する研究

(118)プロパルギルアルコールを原料とする2-アミノピリミジンの合成に関する研究

抗ヒスタミン剤の研究 (第3報)

2-Benzylaminopyrimidine was prepared by the application of propargyl aldehyde to benzylguanidine, and condensation with dimethylaminoethyl chloride gave N, N-dimethyl-N′-benzyl-N′-(2-pyrimidyl)-ethylenediamine. By a similar method, compounds containing methoxyl, bromine, chlorine, and fluorine in the para-position of the benzyl group were prepared. Application of cyanamide to N, N-dimethyl-N′-benzylethylenediamine gave 1-dimethylaminoethyl-1-benzylguanidine, reaction of propargyl aldehyde to which yielded N, N-dimethyl-N′-benzyl-N′-(2-pyrimidyl)-ethylenediamine. Pharmacological tests revealed that the compound possessing fluorine in the para-position of the benzyl group had the most strongest antihistamine acitivity.