Condensed‐Phase, Halogen‐Bonded CF₃I and C₂F₅I Adducts for Perfluoroalkylation Reactions

Abstract

A family of practical, liquid trifluoromethylation and pentafluoroethylation reagents is described. We show how halogen bonding can be used to obtain easily handled liquid reagents from gaseous CF3I and CF3CF2I. The synthetic utility of the new reagents is exemplified by a novel direct arene trifluoromethylation reaction as well as adaptations of other perfluoroalkylation reactions.

Transition metal- and organophotocatalyst-free perfluoroalkylation reaction of amino(hetero)aromatics initiated by the complex [(TMEDA)I·I3] and visible light

“…Also, from Table S1, † there seems to be the presence of complexes between peruoroalkyl iodides and aminoaromatic compounds, 16 the existence of which result in chemical shi changes of the signal from ICF 2 -R F in the 19 F NMR spectra when n-C 4 F 9 I is in the presence of the amino substrate as compared with the innate chemical shi value of ICF 2 -R F signal, interpreted as halogen bonding to the nitrogen atom of the substrate. 17 The -CF 2 I signals in the 19 F NMR spectra of n-C 4 F 9 I in mixtures with amino aromatics (2,4,6-triaminopyrimidine, 2,4-dihydroxy-6-methylpyrimidine, 2,4-diamino-6-hydroxypyrimidine, respectively) are reported in Table S1, † where the similar upeld chemical shis of the ICF 2 -R F can be observed. Analysis of the data presented in Table S1, † also reveals that the substituent amino group in amino aromatic compounds exerts a more favored halogen-bonding interaction with I-C 4 F 9 than the ringnitrogen does, based on the magnitude of the upeld shis.…”

“…The TMEDA$2-CF 3 I complex has been postulated by Ritter 15,17 and colleagues, based on calculations, X-ray crystallographic analysis, and spectroscopic data ( 1 H, 19 F, 13 C NMR). A complex between a nitrogen base and R F -I has very recently been postulated to generate R F radicals upon visible light irradiation.…”

New approaches to organocatalysis based on C–H and C–X bonding for electrophilic substrate activation

“…Not only halogens, but also neutral halogen-containing organic molecules were found to form stable adducts with neutral and charged Lewis bases, and to account for this IUPAC provided the following recommendation “A halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity” [68]. Such complexes may have substantially different properties from the uncomplexed organohalides, which is well exemplified by the at room temperature liquid complex of gaseous iodotrifluoromethane (BP = −23 ºC) and tetramethylguanidine containing a halogen (I···N) bond [70]. …”

A class of effective decarboxylative perfluoroalkylating reagents: [(phen)2Cu](O2CRF)

“…[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35] There is, however, few examples for the introduction of the longer-chain perfluoroalkyl moieties, such as the C 2 F 5 group, into organic molecules (Scheme 2). 36,37,38 For instance, Hartwig and coworkers successfully employed stable (phen)Cu(C 2 F 5 ), prepared from reaction of CuOt-Bu with C 2 F 5 SiMe 3 , for pentafluoroethylation of arylboronate esters and heteroaryl bromides. [39][40][41] Grushin's groups reported the ligandless Cu(C 2 F 5 ) in situ prepared by the direct cupration of economical C 2 F 5 H 42 and Mikami's groups later reported the same reagent synthesized from ethyl pentafluoropropionate.…”