119367-68-9Relevant academic research and scientific papers
Stereoselective synthesis of cis-1,3-disubstituted 1,3-dihydroisobenzofurans via arenechromium tricarbonyl methodology.
Coote, Steven J.,Davies, Stephen G.,Middlemiss, David,Naylor, Alan
, p. 81 - 88 (1989)
Phthalanchromium tricarbonyl is converted by t-butyllithium and alkyl halides completely stereoselectively into the corresponding exo-1-methyl, ethyl and benzyl derivatives.Double methylation of phthalanchromium tricarbonyl generates completely stereoselectively exo-cis-1,3-dimethylphthalanchromium tricarbonyl, from which cis-1,3-dimethylphthalan is liberated on oxidation.In contrast, double methylation of phthalan itself produces a 40/60 mixture of cis- and trans-1,3-dimethylphthalan.
A novel route to unsymmetrical stilbene derivatives via intramolecular free radical ipso substitution reactions
Godfrey, Christopher R. A.,Hegarty, Philip,Motherwell, William B.,Uddin, Muhammed K.
, p. 723 - 726 (1998)
Unsymmetrical stilbene derivatives can be prepared via intramolecular free radical ipso substitution reactions using suitably constituted vinyl sulfonate and sulfonamide tethering chains.
Copper-Catalyzed Enantioselective Hydroalkoxylation of Alkenols for the Synthesis of Cyclic Ethers
Chen, Dake,Berhane, Ilyas A.,Chemler, Sherry R.
supporting information, p. 7409 - 7414 (2020/06/29)
The copper-catalyzed enantioselective intramolecular hydroalkoxylation of unactivated alkenes for the synthesis of tetrahydrofurans, phthalans, isochromans, and morpholines from 4- and 5-alkenols is reported. The substrate scope is complementary to existing enantioselective alkene hydroalkoxylations and is broad with respect to substrate backbone and alkene substitution. The asymmetric induction and isotopic labeling studies support a polar/radical mechanism involving enantioselective oxycupration followed by C-[Cu] homolysis and hydrogen atom transfer. Synthesis of the antifungal insecticide furametpyr was accomplished.
Intramolecular Generation of Oxonium Ylides from Functionalized Arylcarbenes
Kirmse, Wolfgang,Kund, Klaus
, p. 1465 - 1473 (2007/10/02)
Arylcarbenes carrying alkoxyalkyl groups in the ortho position have been generated by flash pyrolysis and photolysis of appropriate tosylhydrazone sodium salts.In the gas phase and in a aprotic solvents, interaction of the carbenes with the lone electron pairs of oxygen competes efficiently with insertion into C-H bonds.Both five- and six-membered cyclic oxonium ylides have been generated.The ylides 23, 37, 61b, and 74 undergo 1,2 shifts of benzyl groups with ease, even if ring contraction to highly strained benzocyclobutenes is involved (23, 74).The oxonium ylides37 and 61b strongly prefer the nonconcerted Stevens rearrangement to the sigmatropic Sommelet rearrangement, in contrast to analogous ammonium ylides.Alkyl shifts occur to a very minor extent, if at all.Evidence is presented that alcohols intercept both the carbenes and the oxonium ylides.Protonation of the ylides leads to cyclic oxonium ions, which undergo nucleophilic cleavage of the C-O bonds.Acid catalyzed decomposition of the appropriate diazo compounds gives rise to six-membered, but not to five-membered, cyclic oxonium ions, thus confirming the different intramolecular reactivities of arylcarbenes and benzyl cations.The efficiency of carbene interception increases with increasing acidity of the medium, suggesting nucleophilic behavior (protonation) of the arylcarbenes.
