102503-71-9

Upstream product

• 102503-69-5 (2-Allyloxy-1-nitro-ethyl)-benzene 
• 96-09-3 styrene oxide 
• 1666-13-3 diphenyl diselenide 
• 90173-15-2 2-methyl-3-phenylbut-3-en-1-ol 
• 5468-44-0 α-nitrostyrene 
• 79092-14-1 2-hydroxy-1-phenylethyl phenyl selenide 
• 286-20-4 cyclohexane-1,2-epoxide 
• 185421-68-5 2-(allyloxy)-1-phenylethyl phenyl selenide 

Relevant academic research and scientific papers

Diastereocontrol by trialkylaluminums in the synthesis of tetrahydrofurans via radical cyclization

(matrix presented) The influence of various Lewis acids in the radical cyclization of β-allyloxyalkyl phenyl selenides was investigated. Whereas the unperturbed cyclization afforded trans-2,4-disubstituted tetrahydrofurans as the major products (cis/trans ≈ 1/4.5), cyclization in the presence of trialkylaluminums (3 equiv) afforded predominantly (cis/trans ≈ 7/1) the corresponding cis-isomers.

Diastereoselective Intramolecular Hydride Transfer Triggered by Electrophilic Halogenation of Aryl Alkenes

Diastereoselective hydride transfer could be triggered by electrophilic halogenation (bromination or fluorination) of homoallylic alcohol O-Bn ethers. The resulting diastereomerically enriched haloalkyl alcohols underwent subsequent intramolecular nucleop

Microwave-assisted group-transfer cyclization of organotellurium compounds

Primary- and secondary-alkyl aryl tellurides, prepared by arenetellurolate ring-opening of epoxides/O-allylation, were found to undergo rapid (3-10 min) group-transfer cyclization to afford tetrahydrofuran derivatives in 60-74% yield when heated in a microwave cavity at 250 °C in ethylene glycol or at 180 °C in water. To go to completion, similar transformations had previously required extended photolysis in refluxing benzene containing a substantial amount of hexabutylditin. The only drawback of the microwave-assisted process was the loss in diastereoselectivity which is a consequence of the higher reaction temperature. Substitution in the Te-aryl moiety of the secondary-alkyl aryl tellurides (4-OMe, 4-H, 4-CF3) did not affect the outcome of the group-transfer reaction in ethylene glycol. However, at lower temperature, using water as a solvent, the CF3 derivative failed to react. The microwave-assisted group-transfer cyclization was extended to benzylic but not to primary- and secondary-alkyl phenyl selenides.

Tetrahydrofuran derivatives from epoxides via group transfer cyclization or reductive radical cyclization of organotellurium and organoselenium intermediates

Monosubstituted epoxides were regiospecifically ring-opened from the sterically least hindered side by benzenetellurolate and benzeneselenolate reagents to afford aryl β-hydroxyalkyl tellurides and selenides, respectively. These materials were O-allylated by treatment with allylic bromides/sodium hydride in tetrahydrofuran and O-prop-2-ynylated when reacted with propargyl bromide/sodium hydride. On photolysis in benzene containing 40 mol % of hexabutylditin, the β-(allyloxy)alkyl aryl tellurides were found to undergo group transfer cyclization to afford 2-substituted 4-[(aryltelluro)methyl]tetrahydrofurans (cis/trans = 1/3-1/10). The aryl β-(prop-2-ynyloxy)alkyl tellurides similarly afforded 2-substituted 4-[(aryltelluro)methylene]tetrahydrofurans with an E/Z-ratio close to unity. The β-(allyloxy)alkyl aryl selenides and aryl β-(prop-2-ynyloxy)alkyl selenides failed to undergo group transfer cyclization. In the presence of tributyltin hydride and 2,2'-azobisisobutyronitrile, the former compounds were found to undergo reductive radical cyclization in high yields to afford 2-substituted 4-methyltetrahydrofurans (cis/trans = 1/3-1/10). Aryl β-(prop-2-ynyloxy)alkyl selenides similarly afforded 2-substituted 4-methylenetetrahydrofurans. 2-Alkoxy-2-(allyloxy)ethyl phenyl selenides, prepared by allyloxyselenenation of vinyl ethers, were found to undergo reductive radical cyclization to afford 2-alkoxy-4-methyltetrahydrofurans (cis/trans = 13-1/4). The preference for formation of trans-2,4-disubstituted tetrahydrofurans in the group transfer and reductive radical cyclizations was rationalized assuming a chairlike transition state with a preferred adoption of a pseudoequatorial position of the 2-substituent. By carrying out the reactions at lower temperatures (ambient or -45°C), using triethylborane as an initiator, it was possible to further increase the trans selectivity in the reductive cyclizations.

DENITROHYDROGENATION OF ALIPHATIC NITRO COMPOUNDS AND A NEW USE OF ALIPHATIC NITRO COMPOUNDS AS RADICAL PRECURSORS

Aliphatic nitro groups are replaced by hydrogen on treatment with tributyltin hydride which proceeds via free radical chain processes.As the nitro group is selectively denitrated and other reducible groups are not affected with tributyltin hydride, this reaction can be used as a method for removing the nitro group from polyfunctional compounds.The radical intermediates generated via denitration can be also used for the carbon-carbon bond forming reactions.