Relative Electrophilic Fluorinating Power as Assayed by Competitive Catalytic Halogenation Reactions

Catalytic fluorination/chlorination competition experiments of β-keto ester 5 were used to assess the relative fluorinating activity of various electrophilic NF reagents (containing an NF bond). Thus, in the halogenation reactions catalyzed by the [Ti(TADDOLato)] complex 1 (=bis(acetonitrile)dichloro[(4R,5R)-2,2-dimethyl-α,α,α′,α′-tetra(naphthalen-1-yl)-1,3-dioxolane-4,5-dimethanolato(2−)-κO,κO′]titanium), the activity range of a series of commercially available reagents spans more than two orders of magnitude. SelectfluorTM (=1-(chloromethyl)-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate); 9; also called F-TEDA; TEDA=triethylenediamine) reacts more than 100 times faster than 1-fluoropyridinium tetrafluoroborate.

[1]  H. Ibrahim,et al.  Enantioselective halogenation reactions , 2004 .

[2]  Lukas Hintermann,et al.  Titanium-Catalyzed Stereoselective Geminal Heterodihalogenation of β-Ketoesters , 2003 .

[3]  S. Ishihara,et al.  Electrophilic fluorination with N, N'-difluoro-2,2'-bipyridinium salt and elemental fluorine , 2003 .

[4]  Lukas Hintermann,et al.  Titanium Lewis Acids for Asymmetric Catalysis: Synthesis and Structural Characterization of Dichloro[diolato(2−)‐κO,κO′]bis(solvent)titanium ([TiCl2(diolato)(solvent)2]) Complexes , 2002 .

[5]  R. Syvret,et al.  Novel process for generating useful electrophiles from common anions using Selectfluor fluorination agent. , 2002, The Journal of organic chemistry.

[6]  S. Piana,et al.  The mechanism of catalytic enantioselective fluorination: computational and experimental studies. , 2002, Angewandte Chemie.

[7]  Lukas Hintermann,et al.  Catalytic Enantioselective Fluorination of β-Ketoesters. , 2000, Angewandte Chemie.

[8]  Lukas Hintermann,et al.  Catalytic Enantioselective Chlorination and Bromination of β‐Keto Esters , 2000 .

[9]  Dennis H. Evans,et al.  Electrochemical studies of six NF electrophilic fluorinating reagents , 1999 .

[10]  G. Shia,et al.  1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate): An electrophilic fluorinating agent , 1999 .

[11]  M. Nagayoshi,et al.  Synthesis, Properties, and Reactivity of N,N‘-Difluorobipyridinium and Related Salts and Their Applications as Reactive and Easy-To-Handle Electrophilic Fluorinating Agents with High Effective Fluorine Content1 , 1998 .

[12]  R. Banks.  Selectfluor™ reagent F-TEDA-BF4 in action: tamed fluorine at your service , 1998 .

[13]  I. Ojima,et al.  Biomedical Frontiers of Fluorine Chemistry , 1996 .

[14]  G. Pez,et al.  Electrophilic NF Fluorinating Agents. , 1996, Chemical reviews.

[15]  R. Banks,et al.  N-Halogeno compounds. Part 18. 1-Alkyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane salts: user-friendly site-selective electrophilic fluorinating agents of the N-fluoroammonium class , 1996 .

[16]  T. Umemoto,et al.  Highly Selective Fluorinating Agents: a Counteranion-Bound N-Fluoropyridinium Salt System , 1995 .

[17]  R. Banks,et al.  Organofluorine Chemistry: Nomenclature and Historical Landmarks , 1994 .

[18]  A. A. Woolf,et al.  Ordering of electrophilic fluorinating reagents of the NF class , 1994 .

[19]  B. Smart,et al.  Organofluorine chemistry : principles and commercial applications , 1994 .

[20]  J. Savéant,et al.  Controlling factors of stepwise versus concerted reductive cleavages. Illustrative examples in the electrochemical reductive breaking of nitrogen-halogen bonds in aromatic N-halosultams , 1993 .

[21]  G. Pez,et al.  On the relative power of electrophilic fluorinating reagents of the NF class , 1992 .

[22]  P. Bersier,et al.  Electrochemical reduction of nitrogen-flourine Bonds: relevance to the reactivity of electrophilic flourinating agents , 1992 .

[23]  R. Banks,et al.  1-Alkyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane salts: a novel family of electrophilic fluorinating agents , 1992 .

[24]  T. Umemoto,et al.  Syntheses and properties of N-fluoropyridinium salts , 1991 .

[25]  E. Differding,et al.  N-Fluorobenzenesulfonimide: A Practical Reagent For Electrophilic Fluorinations , 1991 .

[26]  T. Umemoto,et al.  Power and Structure-Variable Fluorinating Agents. The N- Fluoropyridinium Salt System. , 1990 .

[27]  F. E. Rogers,et al.  Fluorocarbon Derivatives. II. Cyclic Nitrides , 1957 .