Thermal and photochemical additions of azo esters to unsaturated systems—II
作者:A. Shah、M.V. George
DOI:10.1016/s0040-4020(01)90879-8
日期:1971.1
Diels-Alder adduct under thermal conditions; the same product was obtained in much better yields under photochemical conditions. The reaction of cyclohexa-1,4-diene with diethyl azodicarboxylate under irradiation conditions gave 3-(diethylbicarbamyl)-cyclohexa-1,4-diene and diethyl hydrazodicarboxylate. Cycloocta-1,5-diene reacts with diethyl azodicarboxylate, both under thermal and photochemical conditions
The Chemiluminescent Cycloreversion of an Anthracene-Benzene Biplanemer System both in the Solid State and in the Liquid State
作者:Masaru Kimura、Hideki Okamoto、Setsuo Kashino
DOI:10.1246/bcsj.67.2203
日期:1994.8
In the thermal [4+4]cycloreversions of 9-anthracenecarboxylic acid-benzene 3a, methyl 9-anthracenecarboxylate-benzene 3b, dimethyl (or diethyl) 9,10-anthracenedicarboxylate-benzene 3c (or 3d) and anthracene-1,4-difluoro(or dichloro)benzene 3f (or 3g) biplanemers, chemiluminescene was observed for 3a—d only in the solid state at > 120 °C but not in a liquid phase, while 3f and 3g were not chemiluminescent. Efficient chemiluminescence was observed in the photocycloreversion of all biplanemers tested in both phases. The thermodynamic parameters for the thermal cycloreversion of these biplanemers were collected. Higher activation energies were obtained in the solid state than in the liquid phase. The higher energies favor touch of the S0 surface with the S1 surface at the transition state for effecting the chemiluminescent cycloreversion.
Organometallic compounds in organic synthesis. Part 13. Stereoselectivity of complexation of cyclohexadiene esters
作者:B. M. Ratnayake Bandara、Arthur J. Birch、Warwick D. Raverty
DOI:10.1039/p19820001755
日期:——
Complexation of cyclohexadienes with Fe(CO)3 as the entering group are subject to classical steric hindrance by alkyl groups, but CO2R and related groups introduce a competing factor because they favour sterically the entering group, probably through an intermediate complex. Increase of π-electron availability in the initial 1,4-diene by the attachment of OMe reduces this influence, probably because
Unveiling a Masked Polymer of Dewar Benzene Reveals <i>trans</i>-Poly(acetylene)
作者:Jinwon Seo、Stanfield Y. Lee、Christopher W. Bielawski
DOI:10.1021/acs.macromol.8b02754
日期:2019.4.23
A dibromo derivative of Dewar benzene, trans-5,6-dibromobicyclo[2.2.0]hex-1-ene, was polymerized using ring-opening metathesis polymerization (ROMP). The reaction proceeded in a controlled manner as changing the initial monomer-to-catalyst ratio afforded monodispersed polymers with tunable molecular weights and growing polymer chains were extended upon subsequent exposure to additional monomer. Treatment