18631-83-9

Usage

InChI:InChI=1/C5H8/c1-2-5-3-4-5/h2H,3-4H2,1H3

Upstream product

• 765-42-4 1-cyclopropylethanol 
• 18631-84-0 1-methyl-2-methylenecyclopropane 
• 67301-35-3 3-methyl-4-methylidene-1-pyrazoline 
• 27567-84-6 ethenylidenecyclopropane 
• 77-78-1 dimethyl sulfate 
• 765-43-5 Cyclopropyl methyl ketone 
• 67301-36-4 4-ethylidene-4,5-dihydro-3H-pyrazole 
• 101849-70-1 (E)-5-Chloro-3-trimethylstannyl-2-pentene 
• 98962-38-0 O-(1-cyclopropylethyl)-S-methyl carbonodithioate 

Downstream Products

• 100942-41-4 5-Benzhydryl-2,3-dimethyl-1-phenyl-1H-pyrrole 
• 100942-42-5 2-Benzhydryl-3,4-dimethyl-1-phenyl-1H-pyrrole 
• 125413-55-0 1-(1-Chloroethyl)-1-(2,4-dinitrophenylthio)cyclopropane 

Relevant academic research and scientific papers

EVIDENCE FOR DIAZENYL ALLYL DIRADICALS IN THE THERMOLYSIS OF 4-ALKYLIDENE-1-PYRAZOLINES

Secondary deuterium kinetic isotope effects indicate that the C-N bond anti to the Me group on 4-ethylidene-1-pyrazoline breaks preferentially to the syn bond.It is suggested that the product determining step involves an intramolecular radical displacement of nitrogen, as well as an electrocyclic rotation of the allylic methylene groups of the diazenyl allyl diradical, to generate the cyclopropane ring concerted with the loss of nitrogen.The position of deuterium in the methylmethylenecyclopropane can best be rationalized by this latter step.

Polylithiumorganic compounds. Part 28. The reaction of allene and alkyl substituted allenes with lithium metal

The reaction of allene (3a) and alkyl substituted allenes 1,2-hexadiene (3b), cyclopropylallene (3c), and vinylidene cyclopropane (3d) with lithium metal was investigated in order to access 2,3-dilithioalkenes 4a-d. These dilithioalkenes 4a-d are very reactive in polar solvents like THF and act as strong bases, either metalation of the starting allene 3a-d, the solvent, or sufficiently acidic intermediates like 8 a-d is observed. The metalation products 5-7 show follow-up reactions like 1,3-H shift to the corresponding 1-lithio-1-alkynes 8 and subsequent metalation to the dilithioalkynes 9. Additionally, lithium hydride elimination and ring-chain rearrangement (for 5c) are observed. 1,2-Hexadiene (3b) can be brought to reaction with lithium metal in the apolar solvent pentane, here the follow-up reactions are much slower due to the insolubility of 4b. In all cases the elucidation of the reaction pathways is hampered by the formation of complex mixtures of, amongst others, regio- and stereoisomeric products upon quenching with simple electrophiles.

Carrier for olefin polymerization catalysts

Procedure for the preparation of a solid carrier for olefin polymerization catalysts comprising the steps: a) impregnating a silica with a solution of Mg-chloride in the presence of electron donors, b) drying the impregnated silica obtained in (a) and impregnating it with a solution of Mg-alkyls in SiCl4 at a temperature from ?10 to 20° C., optionally adding a further. amount of electron donors, c) subsequently treating the slurry obtained in (b) at a temperature from 40° C. to reflux temperature, d) drying the carrier obtained in (c). The carrier which is obtained according to the above procedure is advantageously used for the preparation of supported catalysts for the polymerization of olefins

A (Z)-Ethylidenecyclopentane Annulation Method. Total Syntheses of (+/-)-Anhydrooplopanone, (+/-)-Oplopanone, and (+/-)-8-epi-Oplopanone

Transmetalation of (Z)-5-chloro-3-trimethylstannyl-2-pentene (8) with MeLi in tetrahydrofuran (THF) at -78 deg C provides the novel bifunctional reagent (E)-5-chloro-3-lithio-2-pentene (11), which can be transformed readily into the Grignard reagent (12).Copper(I)-catalyzed conjugate addition of (12) to cyclic α,β-unsatured ketones (e.g., 23-29), followed by intramolecular alkylation of the resultant chloro ketones (e.g., 30-36), affords the corresponding (Z)-ethylidenecyclopentane annulation products (e.g., 37-43).This new annulation method played a key role intotal syntheses of the sesquiterpenoids (+/-)-anhydrooplopanone (51), (+/-)-oplopanone (50), and (+/-)-8-epi-oplopanone (70).

Intramolecular Steric Factors in the Thermolysis of 4-Alkylidine-1-pyrazolines

Secondary deuterium kinetic isotope effects and product proportions are measured for several methyl-substituted 4-methylene-1-pyrazolines and deuterated isotopomers.The kinetic data support a single-bond-cleavage mechanism, and the products indicate that three modes of ring closure are required.Evidence is presented for a series of monomethyl compounds to suggest that the mechanism is more complex than a two-step scheme would predict and that the interconversion of a series of intermediates 46 is required.

EXTRACTION OF STANDARD HELMHOLTZ FUNCTIONS FROM AFFINITY RATE DATA

An extrapolation procedure to extract standard Helmholtz functions from empirical kinetic data without reference to reaction mechanisms has been developed using an analytical description of the affinity decay rate.

Sulfonyl carbazates as blowing agents

Sulfonyl carbazates containing at least one group of: wherein the oxygen and the sulphur atoms attach to various organic groups are useful as high temperature blowing agents for gas-expandable polymers. Additionally, novel polyfunctional and secondary