Syntheses, structures, and stabilities of aliphatic and aromatic fluorous iodine(I) and iodine(III) compounds: the role of iodine Lewis basicity | Academic Article individual record
abstract

© 2017 Mukherjee et al. The title molecules are sought in connection with various synthetic applications. The aliphatic fluorous alcohols R fn CH 2 OH (R fn = CF 3 (CF 2 ) n-1 ; n = 11, 13, 15) are converted to the triflates R fn CH 2 OTf (Tf 2 O, pyridine; 22-61%) and then to R fn CH 2 I (NaI, acetone; 58-69%). Subsequent reactions with NaOCl/HCl give iodine(III) dichlorides R fn CH 2 ICl 2 (n = 11, 13; 33-81%), which slowly evolve Cl 2 . The ethereal fluorous alcohols CF 3 CF 2 CF 2 O(CF(CF 3 )CF 2 O) x CF(CF 3 )CH 2 OH (x = 2-5) are similarly converted to triflates and then to iodides, but efforts to generate the corresponding dichlorides fail. Substrates lacking a methylene group, R fn I, are also inert, but additions of TMSCl to bis(trifluoroacetates) R fn I(OCOCF 3 ) 2 appear to generate R fn ICl 2 , which rapidly evolve Cl 2 . The aromatic fluorous iodides 1, 3-R f6 C 6 H 4 I, 1, 4-R f6 C 6 H 4 I, and 1, 3-R f10 C 6 H 4 I are prepared from the corresponding diiodides, copper, and R fn I (110-130 °C, 50-60%), and afford quite stable R fn C 6 H 4 ICl 2 species upon reaction with NaOCl/HCl (80-89%). Iodinations of 1, 3-(R f6 ) 2 C 6 H 4 and 1, 3-(R f8 CH 2 CH 2 ) 2 C 6 H 4 (NIS or I 2 /H 5 IO 6 ) give 1, 3, 5-(R f6 ) 2 C 6 H 3 I and 1, 2, 4-(R f8 CH 2 CH 2 ) 2 C 6 H 3 I (77-93%). The former, the crystal structure of which is determined, reacts with Cl 2 to give a 75:25 ArICl 2 /ArI mixture, but partial Cl 2 evolution occurs upon work-up. The latter gives the easily isolated dichloride 1, 2, 4-(R f8 CH 2 CH 2 ) 2 C 6 H 3 ICl 2 (89%). The relative thermodynamic ease of dichlorination of these and other iodine(I) compounds is probed by DFT calculations.

author list (cited authors)
Mukherjee, T., Biswas, S., Ehnbom, A., Ghosh, S. K., El-Zoghbi, I., Bhuvanesh, N., Bazzi, H. S., & Gladysz, J. A.
publication date
2017
publisher
keywords
  • Nucleophilic Substitution
  • Copper Mediated Perfluoroalkylation
  • Hypervalent Iodine
  • Polar Space Group
  • DFT Calculations
  • Fluorous
  • Chlorination
  • Crystal Structure
altmetric score

3.35

citation count

1