Convenient syntheses of a family of easily recoverable fluorous primary, secondary and tertiary aliphatic amines NH(3-x[(CH2)(m)(CF2)7CF3](x) (m = 3-5; x = 1-3) - Fine tuning of basicities and fluorous phase aff

Article abstract of DOI:10.1002/1099-0690(200007)2000:14<2621::AID-EJOC2621>3.0.CO;2-H

The alcohols HOCH₂(CH₂)(m-1)(CF₂)₇CF₃ [m = 3-5; (CF₂)₇CF₃ = R(f8)] are oxidized to aldehydes O=CH(CH₂)(m-1)R(f8) (Dess-Martin reagent, 90-96%), which are co

Full text of DOI:10.1002/1099-0690(200007)2000:14<2621::AID-EJOC2621>3.0.CO;2-H

FULL PAPER
Convenient Syntheses of a Family of Easily Recoverable Fluorous Primary,
Secondary, and Tertiary Aliphatic Amines NH3؊x[(CH2)m(CF2)7CF3]x
(m ؍ 3؊5; x ؍ 1؊3) ؊ Fine Tuning of Basicities and Fluorous Phase
Affinities
Christian Rocaboy,[a,b] Walter Bauer,[a] and John A. Gladysz*[a,b]
Keywords: Fluorine / Amines / Reductions / Aminations / Partition coefficients / Basicity
The alcohols HOCH2(CH2)m−1(CF2)7CF3 [m
(CF2)7CF3 = Rf8] are oxidized to aldehydes O=CH(CH2)m−1Rf8 (CF3C6F11/toluene, 24 °C, 16/17/18/13/14/15/10/11/12:
(Dess−Martin reagent, 90−96%), which are condensed with Ͼ99.7:Ͻ0.3, Ͼ99.7:Ͻ0.3, 99.5:0.5, 96.5:3.5, 95.1:4.9, 93.0:7.0,
NH2CH2C6H5 and Na(AcO)3BH to give benzylamines 70.0:30.0, 63.2:36.8, 56.9:43.1). The relative basicities to-
=
3−5;
bers of CH2 groups increase or Rf8 groups decrease
NH(CH2C6H5)[(CH2)mRf8] (excess amine, 88−90%) or
N(CH2C6H5)[(CH2)mRf8]2 (excess aldehyde, 85−91%). Sub-
sequent hydrogenolyses (Pd/C, 1 atm H2) give the title prim-
ary amines NH2[(CH2)mRf8] (10−12; 98−99%) or secondary
amines NH[(CH2)mRf8]2 (13−15; 92−99%). The aldehyde con-
densations are repeated with 13−15 to give tertiary amines
N[(CH2)mRf8]3 (16−18; 86−97%) with very high fluorous
phase affinities. These decrease monotonically as the num-
wards CF3CO2H are probed by NMR in CDCl3. Competitions
between N(CH2CH3)3 or N[(CH2)11CH3]3 and 16−18 show
100% or Ͼ95%, Ͼ95% or 85−90%, and 85−90 or 65−70% pro-
tonation of the former. Competitions between 16/17, 17/18,
and 16/18 show 60%, 85−90%, and Ͼ95% protonation of the
latter. Thus, an inductive effect of the Rf8 group is still de-
tected through five CH2 groups.
Introduction
the organic products separated from the fluorous catalyst or
transformed reagent in the low temperature biphasic limit.
Amines are ubiquitous as catalysts and reagents in chem-
istry.[1] As such, there has been ongoing practical, eco-
nomic, and ecological interest in amines Ϫ or their pro-
tonated or alkylated derivatives Ϫ that can easily be reco-
vered and recycled.[2Ϫ6] As would be expected, many ap-
proaches involve polymer-bound amines.[2Ϫ4] Some of these
recovery or immobilization strategies have been designed
for application in combinatorial organic synthesis,[3,5] where
the manipulation of ‘‘orthogonal phases’’[7] plays a critical
role. Other approaches involve nothing more complex than
the fine-tuning of solubility properties,[6] so that the amine
or derivative is easily separated from the product.
One innovative new strategy for recoverable catalysts and
reagents exploits the temperature-dependent immiscibility
(orthogonality) of ‘‘fluorous’’ solvents, such as perfluoroal-
kanes and perfluoroethers, and organic solvents.[8Ϫ10] Many
combinations give bilayers at room temperature, but one
phase at higher temperature. Most organic compounds ex-
hibit much higher affinities for organic solvents. However,
species that are derivatized with sufficient numbers of
‘‘pony tails’’ (CH2)m(CF2)nϪ1CF3 [abbreviated (CH2)mRfn]
can exhibit very high fluorous solvent affinities.[9] As shown
in Figure 1, reactions can be effected under homogeneous
conditions in the high temperature monophasic limit, and
In previous papers, we described convenient routes to a
family of fluorous aliphatic primary and tertiary phos-
phanes PH2(CH2)mRf8 and P[(CH2)mRf8]3.[11,12] The
methylene chain or ‘‘spacer’’ lengths are easily varied from
two to five carbons, allowing the donor/acceptor properties
of the phosphorus to be fine-tuned. In iridium carbonyl de-
rivatives, five methylene groups afforded nearly complete in-
sulation of the electron-withdrawing perfluoroalkyl seg-
ments from the metal, as judged from IR νCO values. These
phosphanes have been applied in a variety of rhodium-cata-
lyzed organic reactions,[13,14] and other studies.[15]
In this paper, we report convenient syntheses of a similar
family of fluorous primary, secondary, and tertiary amines,
NH3Ϫx[(CH2)mRf8]x, where the methylene chains vary from
three to five carbons. We also report partition coefficients
that quantify the fluorous phase affinities of these com-
pounds, and basicity measurements that quantify the insu-
lating efficiencies of the spacers with respect to the nitrogen
lone pairs and the electronegative Rf8 moieties. The end re-
sult is a valuable ‘‘toolkit’’ for the systematic development
of catalytic reactions based upon fluorous trialkylamines or
their metal complexes.
There are somewhat fragmented reports of related
fluorous amines in the literature. These include the primary
and secondary amines NHR(CH2)2Rf6 and NHR(CH2)2Rf8
(R ϭ H, Me), which were prepared from azide precursors
and feature double-methylene insulating spacers,[16] and
secondary and tertiary amines NRRЈCH2Rf7, which feature
[a]
Institut für Organische Chemie, Friedrich-Alexander
Universität Erlangen-Nürnberg,
Henkestrasse 42, 91054 Erlangen, Germany
[b]
Department of Chemistry, University of Utah,
Salt Lake City, Utah 84112, USA
Eur. J. Org. Chem. 2000, 2621Ϫ2628
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
1434Ϫ193X/00/0714Ϫ2621 $ 17.50ϩ.50/0
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C. Rocaboy, W. Bauer, J. A. Gladysz
FULL PAPER
Figure 1. One possibility for catalysis with fluorous solvents [Rmfn ϭ (CH2)m(CF2)nϪ1CF3]
single-methylene spacers.[17] The primary and secondary
amines NHx{(CH2)3Si[(CH2)2Rf6]3}3Ϫx have already been
applied in robotic solution phase parallel syntheses.[5a]
More complex aliphatic[18] and aromatic[19] polyamines have
been used as ligands for fluorous biphase catalysis. Other
amines with pony tails have been prepared as part of studies
directed at other objectives.[20] A variety of aliphatic per-
fluoroamines are also commercially available [e.g., n-butyl-
derived N(Rf4)3]. However, these are nonbasic, with very
low lying nitrogen lone pair energies, due to the marked
inductive effect of the uninsulated perfluoroalkyl groups.[21]
Results
1. Syntheses
We sought to develop a general synthesis of the title com-
pounds NH3Ϫx[(CH2)mRf8]x. The reductive amination of al-
dehydes constitutes one of the most versatile preparations
of amines.[22] Accordingly, the known fluorous primary al-
cohols HOCH2(CH2)mϪ1Rf8 (m ϭ 3Ϫ5) were purchased or
prepared by simple procedures previously described.[12,23,24]
As shown in Scheme 1, reactions with the DessϪMartin re-
agent[25] gave the fluorous aldehydes OϭCH(CH2)mϪ1Rf8
[m ϭ 3 (1), 4 (2), 5 (3)] as clear oils in 90Ϫ96% yields after
Scheme 1. Syntheses of fluorous aldehydes, primary and second-
ary amines
workup. While this work was in progress, a communication 4؊9 were removed under mild hydrogenolysis conditions (1
describing the synthesis of 3 and some related aldehydes by atm H2, 10% Pd/C). Workup gave two classes of the title
an identical route appeared.[24]
compounds: the primary amines NH2[(CH2)mRf8] (10؊12)
As shown in Scheme 1, reductive aminations of 1؊3 were and the secondary amines NH[(CH2)mRf8]2 (13؊15), in
conducted with different stoichiometries. In one version, a Ͼ99Ϫ92% yields.
twofold excess of benzyl amine, NH2CH2C6H5, was used.
As shown in Scheme 2, the analogous tertiary amines
The addition of Na(AcO)3BH in THF[22] then gave the sec- N[(CH2)mRf8]3 (16؊18) could be obtained in two ways. In
ondary amines NH(CH2C6H5)[(CH2)mRf8] (4؊6) as oils or one approach, the primary amines 10؊12 were condensed
white solids in 88Ϫ90% yields after workup. In another ver- with 2.0Ϫ2.4 equivalents of aldehydes 1؊3 under the
sion, a twofold excess of the aldehyde was used, allowing Na(AcO)3BH reductive amination conditions. In the other,
the generated compounds 4؊6 to condense further. the secondary amines 13؊15 were similarly treated with
Workup gave the tertiary amines N(CH2C6H5)[(CH2)mRf8]2 1.0Ϫ1.2 equivalents of the aldehydes. In practice, the latter
(7؊9) in 85Ϫ91% yields. The benzyl-protecting groups in route gave slightly higher yields of 16؊18 (97Ϫ86%), and
2622
Eur. J. Org. Chem. 2000, 2621Ϫ2628

Convenient Syntheses of a Family of Easily Recoverable Fluorous Aliphatic Amines
FULL PAPER
only these procedures are provided in the experimental sec- Table 1. Partition coefficients (24 °C)
tion.
Analyte
CF3C6F11/toluene
10
11
12
13
14
15
16
17
18
19
20
21
22
NH2(CH2CH2CH2Rf8)
70.0:30.0
63.2:36.8
56.9:43.1
96.5:3.5
NH2(CH2CH2CH2CH2Rf8)
NH2(CH2CH2CH2CH2CH2Rf8)
NH(CH2CH2CH2Rf8)2
NH(CH2CH2CH2CH2Rf8)2
NH(CH2CH2CH2CH2CH2Rf8)2
N(CH2CH2CH2Rf8)3
N(CH2CH2CH2CH2Rf8)3
N(CH2CH2CH2CH2CH2Rf8)3
P(CH2CH2Rf8)3
P(CH2CH2CH2Rf8)3
P(CH2CH2CH2CH2Rf8)3
P(CH2CH2CH2CH2CH2Rf8)3
95.1:4.9
93.0:7.0
Ͼ99.7:Ͻ0.3
Ͼ99.7:Ͻ0.3
99.5:0.5
Ͼ99.7:Ͻ0.3[a]
98.8:1.2[a]
98.9:1.1[a]
98.9:1.1[b]
Scheme 2. Synthesis of fluorous tertiary amines
The amines 4؊18 were characterized by microanalysis
[a]
[b]
Data at 27 °C from ref.[11]
Ϫ
Data at 27 °C from ref.[12a]
1
and H- and 13C-NMR spectroscopy, as described in the
experimental section. The NMR properties showed numer-
ous patterns, but usually of a routine nature. For example,
the NCH2CH2 13C signals were generally grouped in ranges
(tertiary amines 16؊18, δ ϭ 52.7Ϫ53.9; secondary amines
13؊15, δ ϭ 48.5Ϫ49.9; primary amines 11؊12, δ ϭ
41.9Ϫ42.1), always downfield of the CH2Rf8 signals (δ ϭ
28.8Ϫ29.9). In the corresponding fluorous phosphanes, this
In order to circumvent this problem, CDCl3 solutions of
16؊18 were first titrated with CDCl3 solutions of
CF3CO2H under constant volume conditions. This quite
strong acid [pKa(H2O) ϭ 0.23] completely protonates typ-
ϩ
ical trialkylamines [pKa(H2O) HNR3 ϭ 11.01, 10.63 for
R ϭ CH2CH3, (CH2)9CH3].[27] Only one set of resonances
downfield/upfield sense is reversed (PCH2,
δ
ϭ
17.9Ϫ21.1).[11,12]
was observed, in agreement with rapid equilibria between
Ϫ
16؊18 and their protonated forms H[16؊18]ϩ CF3CO2
.
The benzyl amines 4؊9 were mainly colorless oils. The
title compounds 10؊18 were low melting solids, except for
the two lightest members 10؊11, which were closer to
waxes. All amines were air-stable for extended periods, al-
though the oils and waxes were best stored in a refrigerator.
DSC measurements on 14؊18 showed only melting endo-
therms. Amines 10؊18 dissolved in quite a broad range of
solvents. All were highly soluble in CHCl3, CF3C6H5, and
fluorous solvents such as CF3C6F11. The primary and sec-
ondary amines 10؊15 were also very soluble in methanol.
The highly fluorous tertiary amines 16؊18 remained spar-
ingly soluble in methanol. None of the amines were soluble
in water or DMSO.
Importantly, as illustrated in Figure 2a, the NCH2 1H-
NMR signals shifted linearly downfield. This calibration
experiment therefore provides an indirect measure of the
Ϫ
relative amounts of 16؊18 and H[16؊18]ϩ CF3CO2 in
CDCl3.[28]
Two reference amines without Rf8 segments were se-
lected, the ethyl and n-dodecyl systems N(CH2CH3)3 and
N[(CH2)11CH3]3. Analogous titrations were conducted, as
depicted in Figure 2b. The latter amine reproducibly gave a
nonlinear response. This is tentatively ascribed to micelle
formation, or other aggregation phenomena subject to a
critical concentration. These are known to give significant
chemical shift perturbations.[29] The absence of analogous
2. Partition Coefficients and Basicities
behavior during the protonation of 16؊18 is noteworthy.
Ϫ
Quantitative data on the fluorous phase affinities of the However, the salts H[17؊18]ϩ CF3CO2 did slowly precip-
title compounds were sought. Accordingly, the CF3C6F11/ itate from CDCl3 under the conditions of Figure 2, indicat-
toluene partition coefficients were determined by GC as ing supersaturation. In the case of 16, this was fast enough
previously reported[9,11,26] and are further described in the at half protonation to preclude completion of the calib-
experimental section. These reflect relative as opposed to ration graph.
absolute solubilities, and are summarized in Table 1. Values
for related phosphanes are also given. Trends are analyzed then combined in a 1:1:1 ratio in CDCl3. Concentrations
in the discussion section. were identical to those of the calibration experiments in
As shown in Table 2, two amines and CF3CO2H were
We next probed the effect of the methylene chain length Figure 2. Two sets of signals were observed Ϫ one for the
upon the basicities of tertiary amines 16؊18. Because of time-averaged unprotonated/protonated form of each
the solubility characteristics noted above, Ka(H2O) or amine. One ratio must be the reciprocal of the other. The
Ka(DMSO) values could not be determined. Thus, the ratios were extrapolated from the calibration graph of each
measurement of relative basicities in nonpolar media was amine, and the results are summarized at the bottom of
attempted. In principle, NMR constitutes a convenient Table 2. The ranges reflect slight dependencies on the calib-
method for determining relative ratios. However, proton ration graphs employed. Importantly, there is a detectable
transfer equilibria are often rapid on NMR time scales. In basicity difference between the amine with the longest
these cases, only the time-averaged signals of two equilibrat- methylene chain (18), and the nonfluorinated reference
ing acids or bases are observed.
amines. The trends are further analyzed below.
Eur. J. Org. Chem. 2000, 2621Ϫ2628
2623

C. Rocaboy, W. Bauer, J. A. Gladysz
Table 2. Relative basicities in CDCl3 at 32 °C
FULL PAPER
1
Figure 2. Representative calibration experiments: H NMR chem-
ical shifts of CH2N signals as a function of nitrogen protonation
Discussion
10; 17 vs. 14 vs. 11; 18 vs. 15 vs. 12). The two amines with
The versatile methodologies in Schemes 1 and 2 allow the highest fluorous phase affinities (16, 17) show no detect-
rapid and high-yield access to a large family of fluorous able residual quantity in the organic phase (Ͻ 0.3%). This
primary, secondary, and tertiary amines (10؊18). Key stra- represents, with respect to the catalysis protocol in Figure 1,
tegic elements include (1) the flexible stoichiometry of re- a very high degree of immobilization. However, in other
ductive amination (1:2 or 2:1), (2) a nitrogen source with an applications, only the ability to extract a substance into a
easily removable N-benzyl group, and (3) the repetitive use fluorous solvent is sought.[5a,7] Here, even the primary
of the same fluorous aldehyde building blocks. Fluorous al- amines 10؊12 exhibit sufficiently high partition coefficients
dehydes of the formula OϭCHCH2Rfn are also readily (70.0:30.0 to 56.9:43.1). The partition coefficients of the ter-
available.[24,30] Thus, homologous amines with double- tiary amines 16؊18 can also be compared with those of
methylene spacers should also be easily accessed. Some pre- the analogous tertiary phosphanes P[(CH2)mRf8]3, (20؊22,
viously reported fluorous amines were noted in the intro- Table 1).[11] The latter values appear to be slightly lower,
duction. Although several of the synthetic approaches used perhaps due to the larger and more polarizable phosphorus.
also have the potential to be versatile, no other extensive
The basicity data for tertiary amines 16؊18 in Table 2
family of fluorous amines has been described to date. Thus, features several ratios that can only be bounded or approx-
we strongly recommend 10؊18, for which key physical imately determined, and must be viewed as semiquantit-
properties have also been carefully defined, as benchmark ative. Nonetheless, the results clearly establish a remarkable
compounds for general adoption and use by the practicing transmission of the electron-withdrawing effect of the per-
fluorous phase community.
fluoroalkyl segment through five methylene groups. Com-
Table 1 summarizes one of the most important physical petitions between N(CH2CH3)3 and 16؊18 show progress-
properties: the partition coefficients. As would be expected ively increasing protonation of the fluorous amine, consist-
from a simple ‘‘like dissolves like’’ model,[8] they become ent with a diminishing inductive effect. Nonetheless, there
lower as the methylene chain is lengthened (10 vs. 11 vs. 12; remains a ∆pKa(CDCl3) of 1.5Ϫ1.9 between the conjugate
13 vs. 14 vs. 15; 16 vs. 17 vs. 18). They also become lower acids of N(CH2CH3)3 and 18. The fluorous amines compete
when pony tails are replaced by NH groups (16 vs. 13 vs. slightly more effectively with the n-dodecyl system
2624
Eur. J. Org. Chem. 2000, 2621Ϫ2628

Convenient Syntheses of a Family of Easily Recoverable Fluorous Aliphatic Amines
FULL PAPER
N[(CH2)11CH3]3, which is a better reference base due to the Regardless, this study has provided three series of nearly
similar number of carbons. Still, a ∆pKa(CDCl3) of 0.9Ϫ1.2 isosteric fluorous amines Ϫ primary, secondary, and ter-
remains with 18.
tiary Ϫ with finely modulated basicities and fluorous phase
Another approach to determining the spacer length affinities. The five methylene groups in each pony tail of
needed to insulate the nitrogen from the perfluoroalkyl tertiary amine 18 bring it to within one pKa unit of the
groups is to compare pairs of fluorous amines until an corresponding amine without fluorines. Future reports
asymptotic limit is reached. Competitions between 16 and from this laboratory will describe fluorous pyridines, and
17, 17 and 18, and 16 and 18 (Table 2) show the expected applications of fluorous bases in catalysis.[32]
basicity order. However, the magnitudes of differences sug-
gest that an asymptotic limit is not at hand, and that longer
Experimental Section
methylene chains will be required. We are somewhat con-
cerned by the greater difference between 17 and 18, as com-
pared to 16 and 17, and plan additional types of physical
measurements (heats of reactions, ionization potentials), as
well as computational studies. At present, we have no evid-
ence for ‘‘nonclassical’’ mechanisms of inductive effect
transmission Ϫ e.g., non-through-bond, microenvironment-
based effects. However, in view of the tendency of fluorous
groups to aggregate, and the nonlinear response of
General: All reactions except hydrogenations were conducted under
N2. Chemicals were treated as follows: THF, ether, toluene, hex-
anes, distilled from Na/benzophenone; CH2Cl2, distilled from
CaH2; CF3C6F11 (Oakwood or ABCR), distilled from P2O5;
HOCH2CH2CH2Rf8 (Oakwood), NH2CH2C6H5 (Aldrich), Na-
(AcO)3BH (Aldrich), CDCl3 (Cambridge Isotope or Aldrich) and
other solvents, used as received. Ϫ NMR spectra were recorded on
Varian 300 MHz or Jeol JMN-400GX FT spectrometers.[33] Ϫ Gas
N[(CH2)11CH3]3 in Figure 2b, the possibility of such contri- chromatography was conducted on Hewlett Packard 5910 or Ther-
moQuest Trace GC 2000 instruments. Ϫ DSC data were recorded
with a Mettler-Toledo DSC821 instrument and treated by standard
methods.[34] Ϫ Elemental analyses were conducted with a Carlo
Erba EA1110 instrument (in-house), or by Atlantic Microlab
(Norcross, Georgia).
butions remains an open question.
Trifluoromethyl groups have previously been shown to
exhibit long range inductive effects through sp3 hybridized
atoms. For example, the pKa(H2O) values of the α-amino
acids HO2CCH(NH2)(CH2)nCH3 and ω-trifluoromethyl
analogs HO2CCH(NH2)(CH2)mCF3 have been compared O؍CHCH2CH2Rf8 (1): A Schlenk flask was charged with the
DessϪMartin reagent (1.97 g, 4.64 mmol)[25] and CH2Cl2 (15 mL).
A solution of HOCH2CH2CH2Rf8 (2.00 g, 4.18 mmol) in CH2Cl2
(25 mL) was added with stirring over 10 min. After 2 h, ether
(50 mL) was added. The white suspension was poured into a solu-
tion of Na2S2O3 (8.06 g, 32.48 mmol; 7 equiv./DessϪMartin re-
agent) in saturated aqueous KHCO3 (100 mL). The organic phase
was separated, washed (100 mL saturated KHCO3), and dried
(MgSO4). Solvent was removed by rotary evaporation, and the oil
was distilled (ca. 80 °C, 1.0·10Ϫ2 Torr) to give 1 as a clear oil
(m ϭ 0Ϫ3).[31] A measurable effect persisted through four
sp3 carbons (m ϭ 3). A similar behavior was observed in
the analogous series of carboxylic acids and protonated
primary amines, including gas phase experiments.[31] It
should be emphasized that the trends in Table 2 reflect the
combined inductive effects of three perfluoroalkyl groups,
and must be normalized for many comparative purposes.
For example, the pKa difference between the conjugate acids
of 12 and the nonfluorinated analog H2N[(CH2)11CH3]
1
(1.98 g, 4.15 mmol, 96%). Ϫ IR (cmϪ1, CHCl3) νCϭO 1730. Ϫ H
should be about one third of that of the corresponding ter- NMR (CDCl3):[33] δ ϭ 2.37Ϫ2.52 (m, 2 H, CH2Rf8), 2.83 (t,
3JHH ϭ 7 Hz, 2 H, OϭCHCH2), 9.84 (br s, 1 H, OϭCH). Ϫ
tiary amines in Table 2.
We have similarly sought to study the electronic proper-
13C{1H} NMR (CDCl3, partial):[33] δ ϭ 23.8 (s, OϭCHCH2), 34.9
2
(t, JCF ϭ 22 Hz, CH2Rf8), 198.0 (s, OϭCH). Ϫ 19F NMR
ties of the fluorous tertiary phosphanes P[(CH2)mRf8]3
3
(CDCl3): δ ϭ Ϫ81.4 (t, JFF ϭ 9 Hz, 3 F, CF3), Ϫ114.8 (br s, 2 F,
(19؊22, Table 1).[12] As noted in the introduction, a series
CF2), Ϫ122.0 (br s, 6 F, CF2), Ϫ123.2 (br s, 2 F, CF2), Ϫ123.9 (br
of iridium carbonyl derivatives has been prepared. The IR
s, 2 F, CF2), Ϫ126.7 (br s, 2 F, CF2).
νCO values show a monotonic decrease with increasing
O؍CHCH2CH2CH2Rf8 (2): The reaction/workup given for 1 was
repeated with HOCH2CH2CH2CH2Rf8 (1.18 g, 2.39 mmol)[12,23]
and the DessϪMartin reagent (1.22 g, 2.87 mmol). This gave 2 as
a clear oil (1.09 g, 2.23 mmol, 93%). Ϫ IR (cmϪ1, CHCl3) νCϭO
numbers of methylene groups, and closely approach the
limit of the nonfluorinated phosphane P[(CH2)7CH3]3 with
m ϭ 5 (ν˜ ϭ 4 cmϪ1). The IR frequencies reflect the donor/
acceptor properties of the iridium fragment, so the induct-
ive effect must pass through one more (and much heavier)
atom than in the protonation of 18. However, a careful ana-
lysis of the phosphane data suggests that seven to eight
methylene groups are required to reach the asymptotic
limit. This also represents our best current estimate for the
length of the methylene chain needed to insulate the nitro-
gen from the Rf8 groups in the title compounds.
1725.
Ϫ δ ϭ 1.89Ϫ2.00 (m, 2 H,
1H NMR (CDCl3):[33]
3
CH2CH2Rf8), 2.05Ϫ2.20 (m, 2 H, CH2Rf8), 2.60 (t, JHH ϭ 7 Hz,
2 H, OϭCHCH2), 9.81 (br s, 1 H, OϭCH). Ϫ 13C{1H} NMR
(CDCl3, partial):[33] δ ϭ 21.0 (s, CH2CH2Rf8), 32.1 (t, JCF
ϭ
2
22 Hz, CH2Rf8), 42.9 (s, OϭCHCH2), 200.6 (s, OϭCH).
O؍CHCH2CH2CH2CH2Rf8 (3):[24] The reaction/workup given for
was repeated with HOCH2CH2CH2CH2CH2Rf8 (3.03 g,
1
5.99 mmol)[24] and the DessϪMartin reagent (2.79 g, 6.59 mmol).
Fluorinated derivatives of every organic functional group
find diverse applications in chemistry. Hence, we anticipate
that the methodologies and compounds described above
will prove useful for many purposes besides the fluorous
This gave 3 as a clear oil (2.72 g, 5.39 mmol, 90%). Ϫ IR (cmϪ1
,
CHCl3) νCϭO 1724. Ϫ H NMR (CDCl3):[33] δ ϭ 1.62Ϫ1.78 (m, 4
1
H, CH2CH2CH2Rf8), 2.01Ϫ2.23 (m, 2 H, CH2Rf8), 2.52 (td,
3
3
3JHH ϭ 7 Hz, JHH ϭ 1 Hz, 2 H, OϭCHCH2), 9.79 (t, JHH
ϭ
immobilization/recovery protocol summarized in Figure 1. 1 Hz, 1 H, OϭCH). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ
Eur. J. Org. Chem. 2000, 2621Ϫ2628
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C. Rocaboy, W. Bauer, J. A. Gladysz
FULL PAPER
2
20.0, 21.6 (2s, 2 C, CH2CH2CH2Rf8), 30.9 (t, JCF ϭ 22 Hz, 2.12.
CH2Rf8), 43.6 (s, OϭCHCH2), 201.5 (s, OϭCH).
Ϫ
1H NMR (CDCl3):[33]
CH2CH2CH2Rf8), 1.92Ϫ2.04 (m, 4 H, CH2Rf8), 2.39 (t, JHH
δ
ϭ
1.47Ϫ1.63 (m,
8
H,
ϭ
3
7 Hz, 4 H, NCH2CH2), 3.51 (s, 2 H, CH2C6H5), 7.22Ϫ7.30 (m, 5
NH(CH2C6H5)(CH2CH2CH2Rf8) (4): A Schlenk flask was charged
with 1 (1.47 g, 3.08 mmol), THF (15 mL), and NH2CH2C6H5
(0.67 mL, 6.06 mmol). Solid Na(AcO)3BH (1.30 g, 6.17 mmol) was
added with vigorous stirring. After 5 h, 1  NaOH (10 mL) was
added to the waxy solution. The mixture was extracted with ether
(3 ϫ 25 mL). The extract was dried (MgSO4), and solvent removal
gave an oil. Column chromatography on silica gel (1:3 v/v ether/
hexanes) gave 4 as a colorless oil (1.58 g, 2.78 mmol, 90%). Ϫ
C18H14F17N (567.3): calcd. C 38.11, H 2.48; found C 38.15, H 2.48.
H, C6H5). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 18.0 (s, 2 C,
2
CH2CH2Rf8), 26.8 (s, 2 C, NCH2CH2), 30.8 (t, JCF ϭ 22 Hz, 2 C,
CH2Rf8), 53.3 (s, 2 C, NCH2CH2), 59.1 (s, CH2C6H5), 127.2, 128.5,
129.0, 140.0 (4s, 6 C, C6H5).
N(CH2C6H5)(CH2CH2CH2CH2CH2Rf8)2 (9): The reaction/workup
given for 7 was repeated with 3 (2.15 g, 4.27 mmol), NH2CH2C6H5
(0.23 mL, 2.13 mmol), and Na(AcO)3BH (1.36 g, 6.41 mmol). This
gave 9 as a colorless oil (2.11 g, 1.95 mmol, 91%). Ϫ C33H27F34N
(1083.5): calcd. C 36.58, H 2.51; found C 36.62, H 2.43. Ϫ 1H
NMR (CDCl3):[33] δ ϭ 1.21Ϫ1.61 (m, 8 H, CH2CH2CH2CH2Rf8),
1
Ϫ H NMR (CDCl3):[33] δ ϭ 1.20 (br s, 1 H, NH), 1.70Ϫ1.77 (m,
3
2 H, CH2CH2Rf8), 2.05Ϫ2.19 (m, 2 H, CH2Rf8), 2.66 (t, JHH
ϭ
3
7 Hz, 2 H, NCH2CH2), 3.74 (s, 2 H, CH2C6H5), 7.18Ϫ7.31 (m,
5 H, C6H5). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 21.0 (s,
CH2CH2Rf8), 28.9 (t, 2JCF ϭ 22 Hz, CH2Rf8), 48.3 (s, NCH2CH2),
54.0 (s, CH2C6H5), 127.3, 128.3, 128.7, 140.5 (4s, 6 C, C6H5).
1.92Ϫ2.10 (m, 4 H, CH2Rf8), 2.39 (t, JHH ϭ 7 Hz, 4 H,
NCH2CH2), 3.51 (s, 2 H, CH2C6H5), 7.22Ϫ7.30 (m, 5 H, C6H5).
Ϫ
13C{1H} NMR (CDCl3, partial):[33]
δ
ϭ
20.2 (s,
2
C,
ϭ
2
CH2CH2Rf8), 27.0, 27.1 (2s, 4 C, NCH2CH2CH2), 31.8 (t, JCF
22 Hz, 2 C, CH2Rf8), 55.6 (s, 2 C, NCH2CH2), 59.1 (s, CH2C6H5),
127.0, 128.3, 128.9, 140.2 (4s, 6 C, C6H5).
NH(CH2C6H5)(CH2CH2CH2CH2Rf8) (5): The reaction/workup
given for 4 was repeated with 2 (1.34 g, 2.73 mmol), NH2CH2C6H5
(0.60 mL, 5.70 mmol), and Na(AcO)3BH (1.15 g, 5.46 mmol). This
gave 5 as a colorless oil that solidified upon standing (1.37 g,
NH2(CH2CH2CH2Rf8) (10): A Schlenk flask was charged with 10%
Pd/C (0.150 g, 0.140 mmol) and a solution of 4 (1.21 g, 2.13 mmol)
in reagent grade EtOH/hexanes (1:1 v/v, 20 mL), purged with H2
(2Ϫ3 min), and fitted with a thick-walled balloon filled with H2 (1
atm). The mixture was stirred overnight and filtered through a cel-
ite plug (5 cm). The solvent was removed by rotary evaporation
and oil pump vacuum to give 10 as a white waxy solid (0.99 g,
2.08 mmol, 98%). Ϫ C11H8F17N (477.2): calcd. C 27.69, H 1.67;
2.35 mmol, 88%), m.p. 32Ϫ33 °C (capillary), 30.2 °C (DSC).[34]
Ϫ
C19H16F17N (581.3): calcd. C 39.25, H 2.77; found C 39.39, H 2.89.
Ϫ 1H NMR (CDCl3):[33] δ ϭ 1.38 (br s, 1 H, NH), 1.50Ϫ1.65 (2m,
4 H, CH2CH2CH2Rf8), 1.95Ϫ2.08 (m, 2 H, CH2Rf8), 2.61 (t,
3JHH ϭ 7 Hz, 2 H, NCH2CH2), 3.74 (s, 2 H, CH2C6H5), 7.18Ϫ7.30
(m, 5 H, C6H5). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 18.2 (s,
2
CH2CH2Rf8), 29.7 (s, NCH2CH2), 30.9 (t, JCF ϭ 22 Hz, CH2Rf8),
1
found C 27.70, H 1.68. Ϫ H NMR (CDCl3):[33] δ ϭ 1.00 (br s, 2
48.9 (s, NCH2CH2), 54.2 (s, CH2C6H5), 127.2, 128.3, 128.7, 140.6
(4s, 6 C, C6H5).
H, NH2), 1.71Ϫ1.81 (m, 2 H, CH2CH2Rf8), 2.09Ϫ2.27 (m, 2 H,
3
CH2Rf8), 2.70 (t, JHH ϭ 7 Hz, 2 H, NCH2). Ϫ 13C{1H} NMR
2
(CDCl3, partial):[33] δ ϭ 21.0 (s, CH2CH2Rf8), 28.8 (t, JCF
ϭ
NH(CH2C6H5)(CH2CH2CH2CH2CH2Rf8) (6): The reaction/
workup given for 4 was repeated with 3 (3.01 g, 5.97 mmol),
NH2CH2C6H5 (0.97 mL, 8.95 mmol), and Na(AcO)3BH (1.89 g,
8.95 mmol). This gave 6 as a white solid (3.05 g, 5.12 mmol, 88%),
m.p. 33Ϫ34 °C (capillary), 27.0 °C (DSC).[34] Ϫ C20H18F17N
(595.3): calcd. C 40.35, H 3.04; found C 40.40, H 3.09. Ϫ 1H NMR
(CDCl3):[33] δ ϭ 1.22 (br s, 1 H, NH), 1.35Ϫ1.62 (m, 6 H,
CH2CH2CH2CH2Rf8), 1.91Ϫ2.10 (m, 2 H, CH2Rf8), 2.60 (t,
3JHH ϭ 7 Hz, 2 H, NCH2CH2), 3.74 (s, 2 H, CH2C6H5), 7.18Ϫ7.31
(m, 5 H, C6H5). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 20.3 (s,
CH2CH2Rf8), 27.1 (s, NCH2CH2CH2), 30.0 (s, NCH2CH2), 31.1 (t,
2JCF ϭ 22 Hz, CH2Rf8), 49.3 (s, NCH2CH2), 54.3 (s, CH2C6H5),
127.1, 128.3, 128.6, 140.7 (4s, 6 C, C6H5).
22 Hz, CH2Rf8), 48.5 (s, NCH2).
NH2(CH2CH2CH2CH2Rf8) (11): The reaction/workup given for 10
was repeated with 5 (1.37 g, 2.35 mmol) and 10% Pd/C (0.150 g,
0.140 mmol). This gave 11 as a white waxy solid (1.14 g, 1.32 mmol,
99%). Ϫ C12H10F17N (491.1): calcd. C 29.34, H 2.05; found C
1
29.30, H 2.01. Ϫ H NMR (CDCl3):[33] δ ϭ 1.22 (br s, 2 H, NH2),
1.49Ϫ1.69 (2m, 4 H, CH2CH2CH2Rf8), 2.01Ϫ2.14 (m, 2 H,
3
CH2Rf8), 2.74 (t, JHH ϭ 7 Hz, 2 H, CH2N). Ϫ 13C{1H} NMR
(CDCl3, partial):[33] δ ϭ 17.7 (s, CH2CH2Rf8), 21.0 (s, NCH2CH2),
2
30.9 (t, JCF ϭ 22 Hz, CH2Rf8), 41.9 (s, NCH2).
NH2(CH2CH2CH2CH2CH2Rf8) (12): The reaction/workup given
for 10 was repeated with 6 (1.78 g, 3.00 mmol) and 10% Pd/C
(0.200 g, 0.186 mmol). This gave 12 as a white waxy solid (1.51 g,
N(CH2C6H5)(CH2CH2CH2Rf8)2 (7): The reaction given for 4 was
repeated with 1 (0.894 g, 1.877 mmol), NH2CH2C6H5 (0.102 mL,
0.938 mmol), and Na(AcO)3BH (0.596 g, 2.812 mmol). Workup
gave a crude oil that was chromatographed on silica gel (1:9 v/v
ether/hexanes). This gave 7 as a colorless oil (0.877 g, 0.853 mmol,
91%). Ϫ C29H19F34N (1027.4): calcd. C 33.90, H 1.86; found C
33.83, H 1.78. Ϫ 1H NMR (CDCl3):[33] δ ϭ 1.72Ϫ1.79 (m, 4 H,
3.00 mmol, 100%), m.p. 31 °C (capillary), 30.4 °C (DSC).[34]
Ϫ
C13H12F17N (505.2): calcd. C 30.90, H 2.39; found C 30.55, H 2.50.
Ϫ 1H NMR (CDCl3):[33] δ ϭ 1.15 (br s, 2 H, NH2), 1.39Ϫ1.49 (2m,
4 H, CH2CH2CH2Rf8), 1.57Ϫ1.67 (m, 2 H, NCH2CH2), 1.97Ϫ2.15
3
(m, 2 H, CH2Rf8), 2.71 (t, JHH ϭ 7 Hz, 2 H, NCH2). Ϫ 13C{1H}
NMR (CDCl3, partial):[33] δ ϭ 20.3 (s, CH2CH2Rf8), 26.6 (s,
3
CH2CH2Rf8), 2.03Ϫ2.16 (m, 4 H, CH2Rf8), 2.50 (t, JHH ϭ 7 Hz,
2
CH2CH2CH2Rf8), 31.1 (t, JCF
NCH2CH2), 42.1 (s, NCH2).
ϭ 22 Hz, CH2Rf8), 33.6 (s,
4 H, NCH2CH2), 3.55 (s, 2 H, CH2C6H5), 7.25Ϫ7.35 (m, 5 H,
C6H5). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 18.1 (s, 2 C,
2
NCH2CH2), 28.8 (t, JCF ϭ 22 Hz, 2 C, CH2Rf8), 52.7 (s, 2 C,
NH(CH2CH2CH2Rf8)2 (13): The reaction/workup given for 10 was
repeated with 7 (0.91 g, 0.88 mmol) and 10% Pd/C (0.150 g,
0.140 mmol). This gave 13 as a white solid (0.78 g, 0.84 mmol,
NCH2CH2), 58.8 (s, CH2C6H5), 127.5, 128.6, 129.2, 139.3 (4s, 6
C, C6H5).
N(CH2C6H5)(CH2CH2CH2CH2Rf8)2 (8): The reaction/workup 95%), m.p. 43Ϫ44 °C (capillary), 43.6 °C (DSC).[34] Ϫ C22H13F34N
given for 7 was repeated with 2 (1.25 g, 2.55 mmol), NH2CH2C6H5
(937.3): calcd. C 28.19, H 1.39; found C 28.21, H 1.39. Ϫ 1H NMR
(0.14 mL, 1.27 mmol), and Na(AcO)3BH (0.810 g, 3.825 mmol). (CDCl3):[33] δ ϭ 1.26 (br s, 1 H, NH), 1.74Ϫ1.81 (m, 4 H,
3
This gave 8 as a colorless oil (1.14 g, 1.08 mmol, 85%). Ϫ CH2CH2Rf8), 2.09Ϫ2.24 (m, 4 H, CH2Rf8), 2.70 (t, JHH ϭ 7 Hz,
C31H23F34N (1055.5): calcd. C 35.27, H 2.19; found C 35.43, H
2626
4 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 20.9 (s, 2
Eur. J. Org. Chem. 2000, 2621Ϫ2628

Convenient Syntheses of a Family of Easily Recoverable Fluorous Aliphatic Amines
FULL PAPER
2
C, CH2CH2Rf8), 28.8 (t, JCF ϭ 22 Hz, 2 C, CH2Rf8), 48.5 (s, 2 (2.000 mL), and toluene (2.000 mL), fitted with a mininert valve,
C, NCH2).
vigorously shaken (2 min), and immersed (cap-level) in a 35 °C oil
bath. After 12 h, the bath was removed. After 12Ϫ24 h (24 °C), a
0.400 mL aliquot of each layer was added to 2.000 mL of a 0.0273
 solution of hexadecane in hexane. GC analysis (average of 7Ϫ8
injections) showed 0.00412 mmol of 13 in the CF3C6F11 aliquot
and 0.000398 mmol in the toluene aliquot (91.2:8.8; a 2.000:0.400
scale factor gives a mass balance of 0.0222 g, 93%).
NH(CH2CH2CH2CH2Rf8)2 (14): The reaction/workup given for 10
was repeated with 8 (1.25 g, 1.18 mmol) and 10% Pd/C (0.160 g,
0.150 mmol). This gave 14 as a white solid (1.12 g, 1.17 mmol,
99%), m.p. 61Ϫ62 °C (capillary), 61.1 °C (DSC).[34] Ϫ C24H17F34N
(965.3): calcd. C 30.11, H 1.79; found C 29.94, H 1.86. Ϫ 1H NMR
(CDCl3):[33] δ ϭ 1.16 (br s, 1 H, NH), 1.53Ϫ1.71 (2m, 8 H,
3
CH2CH2CH2Rf8), 2.02Ϫ2.16 (m, 4 H, CH2Rf8), 2.65 (t, JHH
ϭ
Basicity Determinations: The following is representative. Six vials
were charged with 18 (0.0306 g, 0.0206 mmol). Solutions of
CF3CO2H in CDCl3 (0.0206 ) were added to five vials to give
0.25, 0.50, 0.75, and 1.00 CF3CO2H/18 mol ratios. Additional
CDCl3 was added to each vial to give 2.00 mL solutions. Sub-
7 Hz, 4 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 18.3
2
(s, 2 C, CH2CH2Rf8), 29.7 (s, 2 C, NCH2CH2), 30.9 (t, JCF
22 Hz, 2 C, CH2Rf8), 49.5 (s, 2 C, NCH2).
ϭ
NH(CH2CH2CH2CH2CH2Rf8)2 (15): The reaction/workup given
for 10 was repeated with 9 (1.62 g, 1.50 mmol) and 10% Pd/C
(0.200 g, 0.186 mmol). This gave 15 as a white solid (1.36 g,
1
sequent H NMR analyses gave the calibration curves in Figure 2.
Next, a vial was charged with 18 (0.0306 g, 0.0206 mmol), a solu-
tion of CF3CO2H in CDCl3 (1.00 mL, 0.0206 ), and a solution of
N(CH2CH3)3 in CDCl3 (1.00 mL, 0.0206 ). The vial was capped,
shaken, and analyzed by 1H NMR to give the equilibrium data
in Table 2.
1.37 mmol, 92%), m.p. 66Ϫ68 °C (capillary), 66.6 °C (DSC).[34]
Ϫ
C26H21F34N (993.4): calcd. C 31.61, H 2.04; found C 31.56, H 2.10.
Ϫ
1H NMR (CDCl3):[33]
δ
ϭ
1.38Ϫ1.68 (m, H, NH,
9
3
CH2CH2CH2Rf8), 1.98Ϫ2.16 (m, 4 H, CH2Rf8), 2.62 (t, JHH
ϭ
7 Hz, 4 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 20.3
(s, 2 C, CH2CH2Rf8), 27.1 (s, 2 C, CH2CH2CH2Rf8), 30.0 (s, 2
2
Acknowledgments
We thank the US Department of Energy and Deutsche For-
schungsgemeinschaft (DFG; GL 301/3-1) for support of this re-
search.
C, NCH2CH2), 31.1 (t, JCF ϭ 22 Hz, 2 C, CH2Rf8), 49.9 (s, 2
C, NCH2).
N(CH2CH2CH2Rf8)3 (16): A Schlenk flask was charged with 13
(1.00 g, 1.06 mmol), THF (15 mL), and a solution of 1 (0.608 g,
1.28 mmol) in THF (10 mL). Solid Na(AcO)3BH (0.338 g,
1.60 mmol) was added with vigorous stirring. After 4 h, 1  NaOH
(15 mL) was added to the waxy solution. The mixture was extracted
with ether (3 ϫ 20 mL). The extract was dried (MgSO4), and solv-
ent removal gave a solid residue. Column chromatography on silica
gel (1:3 v/v ether/hexanes) gave 16 as a white solid (1.43 g,
[1] [1a]
For an overview, see: The Chemistry of Amino, Nitroso,
Nitro, and Related Groups (Supplement F2); (Ed.: S. Patai),
Wiley: New York, 1996, and similarly titled earlier volumes in
[1b]
this series (1982, 1968). Ϫ
For some contemporary direc-
tions, see: A. Togni, L. M. Venanzi, Angew. Chem. Int. Ed.
Engl. 1994, 33, 497Ϫ526; Angew. Chem. 1994, 106, 517Ϫ547.
1.02 mmol, 97%), m.p. 44 °C (capillary), 44.3 °C (DSC).[34]
C33H18F51N (1397.4): calcd. C 28.36, H 1.29; found C 28.37, H
1.28. 1.68Ϫ1.77 (m, H,
1H NMR (CDCl3):[33]
Ϫ
[2]
E. C. Blossey, W. T. Ford, in: Comprehensive Polymer Science;
(Eds.: G. C. Eastmond, A. Ledwith, S. Russo, Sigwalt, P. Vol-
ume), Pergamon: New York, 1989; Vol. 6, Chapter 3.5.
Ϫ
δ
ϭ
6
[3] [3a]
3
W. Xu, R. Mohan, M. M. Morrissey, Tetrahedron Lett.
CH2CH2Rf8), 2.03Ϫ2.21 (m, 6 H, CH2Rf8), 2.47 (t, JHH ϭ 7 Hz,
[3b]
1997, 38, 7337Ϫ7340. Ϫ
C. Billington, Tetrahedron Lett. 1999, 40, 7031Ϫ7033.
J. Simpson, D. L. Rathbone, D.
6 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 20.9 (s, 3
[3c]
S.
2
C, CH2CH2Rf8), 28.8 (t, JCF ϭ 22 Hz, 3 C, CH2Rf8), 52.7 (s, 3
C, NCH2).
Boisnard, J. Chastanet, J. Zhu, Tetrahedron Lett. 1999, 40,
7469Ϫ7472. Ϫ [3d] See also: Aldrichimica Acta 1998, 31, 47 (ad-
vertisement).
[4]
[4a] S. Goumri-Magnet, O. Guerret, H. Gornitzka, J. B. Cazaux,
D. Bigg, F. Palacios, G. Bertrand, J. Org. Chem. 1999, 64,
3741Ϫ3744. Ϫ [4b] F. Palacios, D. Aparicio, J. M. de losSantos,
A. Baceiredo, G. Bertrand, Tetrahedron 2000, 56, 663Ϫ669.
N(CH2CH2CH2CH2Rf8)3 (17): The reaction/workup given for 16
was repeated with 14 (0.980 g, 1.023 mmol), 2 (0.501 g, 1.02 mmol),
and Na(AcO)3BH (0.325 g, 1.53 mmol). This gave 17 as a white
solid (1.41 g, 0.98 mmol, 96%), m.p. 37Ϫ38 °C (capillary), 38.5 °C
(DSC).[34] Ϫ C36H24F51N (1439.5): calcd. C 30.03, H 1.68; found
C 30.03, H 1.70. Ϫ 1H NMR (CDCl3):[33] δ ϭ 1.46Ϫ1.68 (m, 12
H, CH2CH2CH2Rf8), 2.02Ϫ2.18 (m, 6 H, CH2Rf8), 2.39 (t, 3JHH ϭ
7 Hz, 6 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 18.2
(s, 3 C, CH2CH2Rf8), 27.0 (s, 3 C, CH2CH2CH2Rf8), 31.9 (t, 2JCF ϭ
22 Hz, 3 C, CH2Rf8), 53.7 (s, 3 C, NCH2).
[5] [5a]
B. Linclau, A. K. Sing, D. P. Curran, J. Org. Chem. 1999,
[5b]
64, 2835Ϫ2842. Ϫ
M. Benaglia, M. Cinquini, F. Cozzi, Tetrahedron Lett. 1999,
40, 2019Ϫ2020.
D. P. Curran, Angew. Chem. Int. Ed. 1998, 37, 1174Ϫ1196; An-
gew. Chem. 1998, 110, 1230Ϫ1255.
I. T. Horvath, Acc. Chem. Res. 1998, 31, 641Ϫ650.
J. C. Hodges, Synlett 1999, 152.
[6]
[7]
[8]
[9]
´
Survey of practical considerations and underlying physical
principles: L. P. Barthel-Rosa, Gladysz, J. A. Coord. Chem. Rev.
N(CH2CH2CH2CH2CH2Rf8)3 (18): The reaction/workup given for
16 was repeated with 15 (0.869 g, 0.874 mmol),
1999, 190Ϫ192, 587Ϫ605.
3 (0.441 g,
[10]
[10a]
Review literature from 1999:
E. deWolf, G. vanKoten, B.-
[10b]
0.874 mmol), and Na(AcO)3BH (0.278 g, 1.31 mmol). This gave 18
as a white solid (1.12 g, 0.754 mmol, 86%), m.p. 44Ϫ45 °C (capil-
lary), 45.4 °C (DSC).[34] Ϫ C39H30F51N (1481.6): calcd. C 28.36, H
1.29, N 1.00; found C 28.37, H 1.28, N 1.01. Ϫ 1H NMR
(CDCl3):[33] δ ϭ 1.39Ϫ1.42 (m, 12 H, CH2CH2CH2Rf8), 1.55Ϫ1.67
(m, 6 H, NCH2CH2), 1.96Ϫ2.14 (m, 6 H, CH2Rf8), 2.37 (t, 3JHH ϭ
7 Hz, 6 H, NCH2). Ϫ 13C{1H} NMR (CDCl3, partial):[33] δ ϭ 20.3
(s, 3 C, CH2CH2Rf8), 27.2 (s, 6 C, CH2CH2CH2CH2Rf8), 31.0 (t,
2JCF ϭ 22 Hz, 3 C, CH2Rf8), 53.9 (s, 3 C, NCH2).
J. Deelman, Chem. Soc. Rev. 1999, 28, 37Ϫ41. Ϫ
R. H.
[10c]
Fish, Chem. Eur. J. 1999, 5, 1677Ϫ1680. Ϫ
M. Cavazzini,
F. Montanari, G. Pozzi, S. Quici, J. Fluorine Chem. 1999, 94,
[10d]
183Ϫ193. Ϫ
U. Diederichsen, Nachr. Chem. Tech. Lab.
1999, 47, 805Ϫ809.
[11]
L. J. Alvey, D. Rutherford, J. J. J. Juliette, J. A. Gladysz, J. Org.
Chem. 1998, 63, 6302Ϫ6308.
[12] [12a]
´
L. J. Alvey, R. Meier, T. Soos, P. Bernatis, J. A. Gladysz,
Eur. J. Inorg. Chem., in press. Ϫ [12b] L. J. Alvey, Ph.D disserta-
tion, University of Utah, 1999; Chapter 4.
[13]
´
I. T. Horvath, G. Kiss, R. A. Cook, J. E. Bond, P. A. Stevens,
Partition Coefficients:[11,26] The following is representative. A
10 mL vial was charged with 13 (0.0240 g, 0.0240 mmol), CF3C6F11
´
J. Rabai, Mozeleski, E. J. J. Am. Chem. Soc. 1998, 120,
3133Ϫ3143.
Eur. J. Org. Chem. 2000, 2621Ϫ2628
2627

C. Rocaboy, W. Bauer, J. A. Gladysz
FULL PAPER
[14] [14a]
[23]
[24]
´
D. Rutherford, J. J. J. Juliette, C. Rocaboy, I. Horvath, J.
J. O. Metzger, R. Mahler, A. Schmidt, Liebigs Ann. 1996,
693Ϫ696.
L. Leveque, LeM. Blanc, R. Pastor, Tetrahedron Lett. 1998,
[14b]
A. Gladysz, Catalysis Today 1998, 42, 381Ϫ389. Ϫ
J. J. J.
´
Juliette, D. Rutherford, I. T. Horvath, J. A. Gladysz, J. Am.
´ ˆ
[14c]
Chem. Soc. 1999, 121, 2696Ϫ2704. Ϫ
L. V. Dinh, J. A.
39, 8857Ϫ8860.
[25] [25a]
Gladysz, Tetrahedron Lett. 1999, 40, 8995Ϫ8998.
D. B. Dess, J. C. Martin, J. Am. Chem. Soc. 1991, 113,
[15] [15a]
[25b]
´
M.-A. Guillevic, C. Rocaboy, A. M. Arif, I. T. Horvath, J.
7277Ϫ7287. Ϫ
M. Frigerio, M. Santagostino, S. Sputore,
A. Gladysz, Organometallics 1998, 17, 707Ϫ717. Ϫ [15b] V. Her-
J. Org. Chem. 1999, 64, 4537Ϫ4538.
[26]
[27]
[28]
´
rera, P. J. F. deRege, I. T. Horvath, T. L. Husebo, R. P. Hughes,
C. Rocaboy, D. Rutherford, B. L. Bennett, J. A. Gladysz, J.
Phys. Org. Chem. 2000, 13, in press.
[15c]
Inorg. Chem. Commun. 1998, 1, 197Ϫ199. Ϫ
C. Li, S. P.
´
Nolan, I. T. Horvath, Organometallics 1998, 17, 452Ϫ456.
LangeЈs Handbook of Chemistry; 13th Edition, (Ed.: J. A.
[16] [16a]
F. Szönyi, F. Guennouni, A. Cambon, J. Fluorine Chem.
1991, 55, 85Ϫ92. Ϫ [16b] F. Guennouni, F. Szönyi, A. Cambon,
Synth. Commun. 1994, 24, 2653Ϫ2660.
Dean), McGrawϪHill: New York, 1985; Section 5, Tables 5Ϫ8.
[28a]
For related approaches to Ka determinations, see:
D. L.
Holmes, D. A. Lightner, Tetrahedron 1996, 52, 5319Ϫ5338. Ϫ
[28b] S. Braun, H.-O. Kalinowski, S. Berger, 150 and More Basic
NMR Experiments; Wiley-VCH: New York, 1996; pp 279Ϫ281.
I. Huc, R. Oda, Chem. Commun. 1999, 2025Ϫ2026, and refer-
ences therein.
[17]
´
L. E. Kiss, J. Rabai, L. Varga, I. Kövesdi, SYNLETT 1998,
1243Ϫ1245.
[18] [18a]
[29]
J.-M. Vincent, A. Rabion, V. K. Yachandra, R. H. Fish,
Angew. Chem. Int. Ed. Engl. 1997, 36, 2346Ϫ2349; Angew.
[18b]
[30] [30a]
Chem. 1997, 109, 2438Ϫ2440. Ϫ
G. Pozzi, M. Cavazzini,
K. Uneyama, K. Kitagawa, Tetrahedron Lett. 1991, 32,
[30b]
S. Quici, S. Fontana, Tetrahedron Lett. 1997, 38, 7605Ϫ7608.
3385Ϫ3386. Ϫ
Laurent,h. PH. Blancou, A. Commeyras,
[18c]
[30c]
´ `
F. DeCampo, D. Lastecoueres, J.-M. Vincent, J.-B.
Ϫ
Tetrahedron Lett. 1992, 33, 2489Ϫ2492. Ϫ
X.-Q. Tang, C.-
Verlhac, J. Org. Chem. 1999, 64, 4969Ϫ4971.
M. Hu, J. Chem. Soc, Perkin Trans. 1 1994, 2161Ϫ2163.
M. Schlosser, Angew. Chem. Int. Ed. 1998, 37, 1496Ϫ1513; An-
[19]
[31]
S. Quici, M. Cavazzini, S. Ceragioli, F. Montanari, G. Pozzi,
Tetrahedron Lett. 1999, 40, 3647Ϫ3650.
gew. Chem. 1998, 110, 1538Ϫ1556.
[20] [20a]
[32]
[33]
H. Uno, Y. Shiraishi, K. Shimokawa, H. Suzuki, Chem.
C. Rocaboy, J. A. Gladysz, manuscript in preparation.
Ambient probe temperature in CDCl3 and referenced as fol-
lows: 1H, residual internal CHCl3 (δ ϭ 7.27); 13C, internal
CDCl3 (δ ϭ 77.2); 31P, external 85% H3PO4 (δ ϭ 0.00); 19F,
external CFCl3 (δ ϭ 0.00).
Lett. 1988, 729Ϫ732. Ϫ [20b] A. R. Katritzky, Z. Zhang, M. Qi,
Tetrahedron Lett. 1997, 38, 7015Ϫ7018.
M. Gaensslen, U. Gross, H. Oberhammer, S. Rüdiger, Angew.
Chem. Int. Ed. Engl. 1992, 31, 1467Ϫ1468; Angew. Chem. 1992,
104, 1525Ϫ1526.
A. F. Abdel-Magid, K. G. Carson, B. D. Harris, C. A. Maryan-
off, R. D. Shah, J. Org. Chem. 1996, 61, 3849Ϫ3862, and
extensive literature background therein.
[21]
[22]
[34]
H. K. Cammenga, M. Epple, Angew. Chem. Int. Ed. Engl. 1995,
34, 1171Ϫ1187; Angew. Chem. 1995, 107, 1284Ϫ1301.
Received February 14, 2000
[O00073]
2628
Eur. J. Org. Chem. 2000, 2621Ϫ2628