Mild, Safe, and Versatile Reagents for (CF₂)_n Transfer and the Construction of Fluoroalkyl-Containing Rings

Abstract

The preparation of new dizinc reagents [(MeCN) 2 Zn((CF 2 ) n ) 2 Zn(MeCN) 2 ] (n = 3, 4, and 6) is reported. We show that the C4 reagent can readily transmetalate nickel to form a mononuclear perfluoronickelacycle. We also demonstrate that the reagents can be used to prepare novel fluoroorganics containing either perfluoroalkyl ring systems or perfluoroalkyl linked arenes under relatively mild conditions.

Exploring Mechanisms in Ni Terpyridine Catalyzed C–C Cross-Coupling Reactions—A Review

“…For nickel, single electron pathways between the oxidation states (0, +I, +II, +III, and +IV) often occur in addition to oxidative addition and reductive elimination [24][25][26]31,32]. Out of the many applications of nickel(II) catalysts in C-C or C-E cross-coupling reactions, we will focus in this contribution on the Negishi-type reactions [15,18,19,25,26,33] using organometallic zinc reagents, and on electrochemically driven C-C cross-coupling reactions. Also, instead of providing a literature overview of the many transformation that have been achieved using these methods, we will focus on selected studies that have provided mechanistic insight into these reactions.…”

Fluorous Organometallic Chemistry

“…The reactions of C n F 2n+1 I with diethylzinc generate bis(perfluoroalkyl)zinc compounds, Zn(C n F 2n+1 ) 2 ·2solv (solv ¼ MeCN, THF, DMSO), which have been comprehensively characterised in solution by multinuclear NMR [104,105]. Reaction of 1,6-diiodododecafluorohexane with ZnEt 2 generates an unusual bisperfluoroalkyl-bridged dizinc species, [(solv) 2 Zn(μ 2 -C 6 F 12 )Zn(solv) 2 ] (solv ¼ MeCN, 1,3-dimethyl-3,4,5,6-tetrahydro-1(1H)-pyrimidinone); the latter has been used as a transfer reagent for the perfluoroalkyl chain to form perfluoro-bridged diaryls in the presence of CuCl [106]. Some experimental details for the isolation of the highly active Lewis acid scandium and ytterbium(III) tris(perfluoroalkylsulfonyl) methide catalysts have been reported [107][108][109][110].…”

Improved synthesis, structure, and reactivity of 1,4-bis(trimethylsilyl)octafluorobutane

“…(f). The perfluorometallacyclopentane derivatives have, to date, only been prepared by the oxidative coupling of tetrafluoroethylene or through the use of recently reported dizinc reagents [19]. An approach to metallacyclic complexes using disilylated perfluoroalkane reagents would be desirable, as the silyl complexes have a longer shelf life than the perfluoroalkyl zinc reagents.…”

“…Compound 1 crystallizes in the P2 1 2 1 2 1 space group, with two molecules in the asymmetric unit. The Si-C CF3 bond lengths of all the molecules in the unit cell average to 1.942 (19) Å , which is similar to the Si-C CF3 bond length of 1.943(12) that was determined experimentally for trimethyl(-trifluoromethyl)silane by Olejniczak and co-workers [25]. Woski and co-workers determined a much shorter Si-C CF3 bond length of 1.917(5) Å for trimethyl(trifluoromethyl)silane, but this value was much different than those derived from gas phase calculations (1.948 Å for Hartree Fock and 1.937 Å for MP2) and microwave spectroscopy/gas electron diffraction techniques (1.941(3) Å ) [26].…”