60011-39-4

Upstream product

• 886-65-7 trans,trans-1,4-Diphenyl-1,3-butadiene 
• 106-51-4 p-benzoquinone 
• 1445-78-9 2,5-Diphenyl-thiophene 
• 926-02-3 tert-butyl vinyl ether 
• 22956-51-0 1,8-diphenylocta-1,7-diyne-3,6-dione 
• 796-30-5 1,4-diphenylnaphthalene 

Relevant academic research and scientific papers

Cobalt-mediated linear 2:1 Co-oligomerization of alkynes with enol ethers to give 1-alkoxy-1,3,5-trienes: A missing mode of reactivity

A variety of 1,6-heptadiynes and certain borylalkynes co-oligomerize with enol ethers in the presence of [CpCo(C2H4)2] (Cp = cyclopentadienyl) to furnish the hitherto elusive acyclic 2:1 products, 1,3,5-trien-1-ol ethers, in preference to or in competition with the alternative pathway that leads to the standard [2+2 + 2] cycloadducts, 5-alkoxy-1,3- cyclohexadienes. Minor variations, such as lengthening the diyne tether, cause reversion to the standard mechanism. The trienes, including synthetically potent borylated derivatives, are generated with excellent levels of chemo-, regio-, and diastereoselectivity, and are obtained directly by decomplexation of the crude mixtures during chromatography. The cyclohexadienes are isolated as the corresponding dehydroalkoxylated arenes. In one example, even ethene functions as a linear cotrimerization partner. The alkoxytrienes are thermally labile with respect to 6πelectrocyclization-elimination to give the same arenes that are the products of cycloaddition. The latter, regardless of the mechanism of their formation, can be viewed as the result of a formal [2+2+2] cyclization of the starting alkynes with acetylene. One-pot conditions for the exclusive formation of arenes are developed. DFT computations indicate that cyclohexadiene and triene formation share a common intermediate, a cobaltacycloheptadiene, from which reductive elimination and β-hydride elimination compete.

Rearrangements in the Cerium(IV) and Manganese(III) Oxidations of Substituted Naphthalenes and the NIH Shift Mechanism

Ceric ammonium sulphate oxidation of 1- and 1,4-disubstituted naphthalenes gives 2- and/or 2,3-disubstituted 1,4-naphthoquinones through migration of substituents (D, Br, Ph).Similar rearrangements are also observed in the manganese(III) oxidation and also in the anodic oxidation of these substrates.The results are consistent with the proposal that these oxidations go through the formation of radical cation followed by reaction with H2O and further oxidation of the radical to the carbocationic intermediate on the way to the corresponding 1,4-naphthoquinone.Oxidation of 1,4-diphenylnaphthalene gives 2,3-diphenyl-1,4-naphthoquinone or 4-hydroxy-2,4-diphenyl-1(4)H-naphthalenone.The results are in accordance with the conclusion that such rearrangements do not require prior formation of arene oxide intermediates, originally proposed for the NIH shift mechanism.

Reaction of trans,trans-1,4-Diphenylbutadiene and Maleic Anhydride. Substituent and Solvent Effects

Diels-Alder adducts from X-substituted diphenylbutadienes (X=p-NMe2, p-OMe, p-Me, m-OMe, H, p-Cl, m-Cl, p-CN, and m-NO2) and maleic anhydride, and from diphenylbutadiene and some dienophiles (N-methylmaleimide, N-phenylmaleimide, and 1,4-benzoquinone), ha