3452-03-7Relevant articles and documents
Unifying the mechanisms for alkane dehydrogenation and alkene H/D exchange with [IrH2(O2CCF3)(PAr3)2]: The key role of CF3CO2 in the "sticky" alkane route
Gerard,Eisenstein,Lee,Chen,Crabtree
, p. 1121 - 1131 (2001)
To understand photochemical and thermal alkane activation with IrH2(O2CCF3)(PAr3)2 (Ar = p-FC6H4), H/D isotope scrambling between alkenes and IrD2(O2CCFsub
Photochemistry of Alkyl Halides. 9. Geminal Dihalides
Kropp, Paul J.,Pienta, Norbert J.
, p. 2084 - 2090 (2007/10/02)
The photobehavior of the geminal dihalides (diiodomethyl)cyclohexane (7), (bromoiodomethyl)cyclohexane (11), (dibromomethyl)cyclohexane (17), (diiodomethyl)cyclopentane (22), 3,3-dimethyl(diiodomethyl)cyclobutane (27), and 8,8-diiodo-2,6-dimethyl-2-octene (31) has been studied and compared with that previously observed for diiodomethane.In all solvents the corresponding vinyl halides (iodomethylene)cyclohexane (13), (bromomethylene)cyclohexane (21), (iodomethylene)cyclopentane (23), 3,3-dimethyl(iodomethylene)cyclobutane (28), or cis- and trans-3,7-dimethyl-1-iodo-1,6-octadiene (33) were obtained, which are thought to arise from α-halo cationic intermediate formed via initial light-induced homolytic cleavage of the carbon-iodine bond followed by electron transfer within the resulting caged radical pair, as shown in Schemes II and III.In the case of diiodide 31 competing intramolecular trapping of the α-iodo cation afforded in addition the cyclized isopulegyl iodide (34).In polar solvents the vinyl iodides were accompanied by the nonhalogenated products methylenecyclohexane (15), 1-methylcyclopentene (25), cyclohexene (26), 4,4-dimethylcyclopentene (29), and cis- and trans-carane (35), which are thought also to arise from the α-halo cationic intermediate. 1.1-Diiodo-2,2-dimethylpropane (1b) afforded 2-methyl-2-butene (6b).Except for carane (35) from diiodide 31 there was no detectable formation of cyclopropanes.In methanol the nucleophilic substitution products (dimethoxymethyl)cyclohexane (14), (dimethoxymethyl)cyclopentane (24), and 1,1-dimethoxy-2,2-dimethylpropane (30) were obtained.It is concluded that geminal dihalides undergo predominant, if not exclusive, photoreaction via initial clea vage of a single carbon-halogen bond in analogy with monohalides and that carbene intermediates are not formed.A similiar conclusion has been reached previously for diiodomethane in the photocyclopropanation of alkenes.
