The Stereochemistry of the Pentacyclo[8.2.1.1^4,7.0^2,9.0^3,8]tetradecanes and -dienes. Norbornene and Norbornadiene Dimers

Proton magnetic resonance spectra of some aromatic amines and derived amides

“…Where the s-trans configuration e.g. (6) is stabilized by intramolecular hydrogen bonding (29,30,44) the spectra of the secondary amines were examined for evidence of deshielding of H-6 due to the proximity of the methyl group (45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58). In fact small upfield shifts of this proton are observcd and these probably arise from enhanced electron donation by the methylamino group as compared to the amino group (43).…”

Promoting Effect of AlCl_3 on the Fe-catalyzed Dimerization of Bicyclo[2.2.1]hepta-2,5-diene

“…After the reaction was completed, the product mixture was neutralized with an aqueous solution of NaHCO 3 and the upper organic layer was recovered and analyzed by GC, GC-Mass, and 1 H NMR. 13,14 …”

“…1,2 It has been also shown that the use of three-component catalytic system consisting of Co(acetylacetonate) 3 (Co(acac) 3 ), triphenylphosphine (TPP), and diethylaluminum chloride (DEAC) or ethylaluminum dichloride (EADC) produces heptacyclic Binor-S (dodecahydro-1,2,4: 5,6,8-dimetheno-s-indecene) as the major product. 3,4 In contrast, the dimerization in the presence of an iron-based three-component catalytic system consisting of Fe(acetylacetonate) 3 (Fe(acac) 3 ), TPP, and DEAC yields hexacyclic endo-endo dimer (hexacyclo [7.2.1.0 2,8 .1 3,7 .1 5,13 . 0 4,6 ]tetradec-10-ene, H nn ) as the major product.…”

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The activity of the catalytic system composed of Fe(acetylacetonate) 3 (Fe(acac) 3 ), triphenylphosphine, and diethylaluminum chloride for the dimerization of bicyclo[2.2.1]hepta-2,5-diene (2,5-norbornadiene, NBD) to produce hexacyclic endo-endo dimer (hexacyclo[7.2.1.0 2,8 .1 3,7 .1 5,13 .0 4,6 ]tetradec-10-ene, H nn ) was significantly enhanced by the presence of AlCl 3 , especially at the molar ratios of NBD/Fe(acac) 3 of 500. XPS analysis of the catalytic systems clearly demonstrates that AlCl 3 facilitates the reduction of Fe(acac) 3 to form active species, Fe(II) and Fe(0) species.

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Computational and experimental studies into NMR characterization of [2+2] cycloaddition products of norbornene

“…A process thermally forbidden by the Woodward-Hoffmann rules [3], this cycloaddition has been achieved using transition metal catalysts or photochemical reactions [4][5][6][7]. The transition-metalcatalyzed dimerization of bicyclo[2.2.1]hept-2-ene (norbornene, nbe) was reported in 1965 [8,9]. Since then various metal complexes have been used as catalysts providing various isomers of pentacyclo [8.2.1.1 4,7 .0 2,9 .0 3,8 ]tetradecane, the [2+2] nbe dimer [10][11][12][13][14].…”