Reduced to the max: Halogenated polycyclic hydrocarbons can be reduced with calcium via two different pathways yielding radical anions due to electron transfer into the π*‐orbital or Grignard‐type reagents due to insertion of Ca into the carbonhalogen bond (see figure).
Stereoselectivity in the formation of tricarbonyliron complexes of some dihydrobiphenyls
作者:B.M.Ratnayake Bandara、Arthur J. Birch、Brian Chauncy
DOI:10.1016/0022-328x(93)83066-5
日期:1993.2
Ratios of isomeric products in complexation of some substituted cyclohexa-1,4- and 1,3-dienes, using Fe(CO)5 or Fe3(CO)12 are significantly affected by the nature of an allylic substituent: CO2Me tends to direct the metal to its occupied face, Ph less so and Me is inhibitory. An appropriately substituted cyclohexadiene gives a single stereoisomer.
Preparation of 1-phenylcyclohexa-2,5-diene-1-carboxylates and their use in free-radical mediated synthesesElectronic supplementary information (ESI) available: experimental procedures for the preparation of 1,4-dihydrobiphenyl,9 1-deuterio-1,4-dihydrobiphenyl, 1-phenylcyclohexa-2,5-diene-1-carboxylic acid with 3,4-dihydrobiphenyl-3-carboxylic acid, 2-(cyclohex-2-enyloxy)ethyl 1-phenylcyclohexa-2,5-diene-1-carboxylate and non-1-en-6-ol. Experimental details of the reactions of cyclopentyl 1-phenylcyclohexa-2,5-diene-1-carboxylate with cyclohexenone, methyl acrylate, methyl methacrylate, acrylonitrile and cyclohexene are included. See http://www.rsc.org/suppdata/p1/b1/b110527m/
作者:Paul A. Baguley、Leon V. Jackson、John C. Walton
DOI:10.1039/b110527m
日期:2002.1.23
Synthetic routes to pure 1-phenylcyclohexa-2,5-diene-1-carboxylic acid and derived esters were developed. Esters containing appropriately unsaturated side chains generated the corresponding alkenyl radicals and hence gave good yields of 5-exo ring closure products in organotin-free reactions. Extrusion of phenyl radicals from the intermediate cyclohexadienyl type radicals was not observed, and this alternative β-scission did not compete under any conditions. Yields from alkylations of olefins in analogous intermolecular processes were, however, poor. As a spin-off from the research, it was found that 1-phenylcyclohexa-2,5-diene-1-carboxylic acid (6) was a useful source of hydroxyformyl (formate) radicals in organic solvents.
Substituent effects on the dehydration of arene hydrates in aqueous solution
作者:Michelle J. O'Mahony、Rory A. More O'Ferrall、Derek R. Boyd、Casey M. Lam、AnnMarie C. O'Donoghue
DOI:10.1002/poc.3174
日期:2013.12
benzenium ion in which direct mesomeric interaction with the substituent occurs, presumably permitted by the coplanar arrangement of the diene and carbocation centre in the intermediate. Data points for 2‐substituted arene hydrates (13f, 13g, 13h, 13i) deviate negatively from the Hammett plot as direct mesomeric interaction with the substituent is not possible in the corresponding benzenium intermediates
Thermal and Photochemical Electron-Transfer Reactions of 4-Chlorobiphenyl with Lithium Diisopropylamides and Diisopropylamine
作者:Yoshio Tanaka、Kazuo Tsujimoto、Mamoru Ohashi
DOI:10.1246/bcsj.60.788
日期:1987.2
A reaction of 4-chlorobiphenyl with lithium diisopropylamide in a polar solvent gave 3- and 4-(diisopropylamino)biphenyl together with biphenyl, similar to the case of photoinduced reactions of 4-chlorobiphenyl with diisopropylamine. A common electron-transfer mechanism is proposed.