ACS Catalysis
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corresponding Pdꢀcatalyzed amination reactions, but aryl
fonates and incorporate this new class of electrophile into proꢀ
cesses for the preparation of specialty chemicals.
fluorosulfonates containing polar functional groups were tolꢀ
erated. Greater yields of amination product were obtained
from reactions of aryl fluorosulfonates containing electronꢀ
withdrawing groups than those containing electronꢀdonating
groups. For example, the amination of 1c (R = pꢀCF3), 1e (R
= pꢀCOOEt), and 1h (R = pꢀCN) occurred in 84%, 81%, and
79% yield, while the amination of 1b (R = pꢀOMe) occurred in
less than 20% yield. Unexpectedly, the amination of 3ꢀ
chlorophenylfluorosulfonate (1g) formed 85% yield of the
desired CꢀN coupled product with complete selectivity for
functionalization of the fluorosulfonate. In contrast, we previꢀ
ously reported that no selectivity for the chloro substituent of
1g was observed in Niꢀcatalyzed Suzuki couplings,11 and nickꢀ
elꢀcatalyzed aminations of aryl chlorides are known to occur
in higher yields than the corresponding amination of other
oxygenꢀbased electrophiles.5h
Although the examples shown herein demonstrate coupling
conditions with aniline, preliminary unoptimized results sugꢀ
gest that judicious choice of ligand enables the coupling of
more nucleophilic alkylamines as well (Scheme 4). The comꢀ
bination of CpPd(cinnamyl) and tBuBrettPhos catalyzes the
amination of pꢀtolylfluorosulfonate with benzylamine in 73%
yield. Likewise, extension of the conditions reported in Table
5 to the Niꢀcatalyzed coupling of an aryl fluorosulfonate with
the secondary aliphatic amine morpholine formed aminated
product, albeit in only 35% yield.
ASSOCIATED CONTENT
This material is available free of charge via the Internet at
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General experimental details, DoE data analysis, and H and 13C
NMR spectra for the amine products 2a-2l.
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AUTHOR INFORMATION
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Corresponding Author
* pshanley@dow.com
ACKNOWLEDGMENT
We thank William J. Kruper and Gregory T. Whiteker for their
guidance at the onset of this work.
REFERENCES
(1)For reviews on BuchwaldꢀHartwig coupling reactions see: (a)
Surry, D. S.; Buchwald, S. L. Angew. Chem., Int. Ed. 2008, 47, 6338ꢀ
6361. (b) Hartwig, J. F. Acc. Chem. Res. 2008, 41, 1534ꢀ1544.
(2) For seminal papers on the Pdꢀcatalyzed amination of aryl broꢀ
mides and triflates: (a) Louie, J.; Hartwig, J. F. Tetrahedron Lett.
1995, 36, 3609ꢀ3612. (b) Guram, A. S.; Rennels, R. A.; Buchwald, S.
L. Angew. Chem. Int. Ed. 1995, 34, 1348ꢀ1350. (c) Wolfe, J. P.;
Buchwald, S. L. J. Org. Chem. 1997, 62, 1264ꢀ1267.
(3)(a) Rappoport, Z., Ed.; The Chemistry of Phenols; John Wiley &
Sons Ltd: Chichester, 2003. (b) Zakzeski, J.; Bruijnincx, P. C. A.;
Jongerius, A. L.; Weckhuysen, B. M. Chem. Rev. 2010, 110, 3552ꢀ
3599.
Scheme 4. Amination of an Aryl-OFs with Alkylamines
(4) (a) Hamann, B. C.; Hartwig, J. F.; J. Am. Chem. Soc. 1998, 120,
7369ꢀ7370. (b) Ogata, T.; Hartwig, J. F. J. Am. Chem. Soc. 2008, 130,
13848ꢀ13849. (c) Fors, B. P.; Watson, D. A.; Biscoe, M. R.; Buchꢀ
wald, S. L. J. Am. Chem. Soc. 2008, 130, 13552ꢀ13554.
(5) (a) Wolfe, J. P.; Buchwald, S. L. J. Am. Chem. Soc. 1997, 119,
6054ꢀ6058. (b) Brenner, E.; Fort, Y. Tetrahedron Lett. 1998, 39,
5359ꢀ5362. (c) Desmarets, C.; Schneider, R.; Fort, Y. J. Org. Chem.
2002, 67, 3029ꢀ3036. (d) Chen, C.; Yang, LꢀM. J. Org. Chem. 2007,
72, 6324ꢀ6327. (e) Manolikakes, G.; Gavryushin, A.; Knochel, P. J.
Org. Chem. 2008. 73, 1429ꢀ1434. (f) Shimasaki, T.; Tobisu, M.;
Chatani, N.; Angew. Chem. Int. Ed. 2010, 49, 2929ꢀ2932. (g) Iglesias,
M. J.; Blandez, J. F.; Fructos, M. R.; Prieto, A.; Álvarez, E.; Belderꢀ
rain, T. R.; Nicasio, M. C. Organometallics 2012, 31, 6312ꢀ6316. (h)
Fine Nathel, N. F.; Kim, J.; Hie, J.; Jiang, X.; Garg, N. K. ACS Catal.
2014, 4, 3289ꢀ3293. (i) Hie, L.; Ramgren, S. D.; Mesganaw, T.; Garg,
N. K. Org. Lett. 2012, 14, 4182ꢀ4185. (j) Ramgren, S. D.; Silberstein,
A. L.; Yang, Y.; Garg, N. K. Angew. Chem. Int. Ed. 2011, 50, 2171ꢀ
2173. (k) Mesganaw, T.; Silberstein, A. L.; Ramgren, S. D.; Fine
Nathel, N. F.; Hong, X.; Liu, P.; Garg, N. K. Chem. Sci. 2011, 2,
1766ꢀ1771. (l) Gao, C.ꢀY.; Yang, L.ꢀM. J. Org Chem. 2008, 73, 1624ꢀ
1627. (m) Tobisu, M.; Shimasaki, T.; Chatani, N. Chem. Let. 2009,
38, 710ꢀ711. (n) Ackermann, L.; Sandmann, R.; Song, W. Org. Lett.
2011, 13, 1784ꢀ1786.
(6)(a) Ge, S.; Green, R. A.; Hartwig, J. F. J. Am. Chem. Soc. 2014,
136, 1617ꢀ1627. (b) Park, N. H.; Teverovskiy, G.; Buchwald, S. L.
Org. Lett. 2014, 16, 220ꢀ223.
(7) (a) Hedayatullah, M.; Guy, A.; Denivelle, L. C. R. Acad. Sc.
Paris. 1974, 278, 57ꢀ59. (b) Firth, W. C. (American Cyanamid Comꢀ
pany). Aryl Sulfate Polymers and Methods for their Production. US
Patent 3,733,304. May 15, 1973. (c) Stang, P. J.; Hanack, M.;
Subramanian, L. R. Synthesis, 1982, 2, 85ꢀ126.
Here we have presented the first examples of palladiumꢀ
and nickelꢀcatalyzed amination of aryl fluorosulfonates with
aryl and aliphatic amines. These reactions occur under mild
conditions with relatively simple catalyst combinations over a
diverse array of functionalized aryl fluorosulfonates. The aryl
fluorosulfonate was demonstrated to be the superior electroꢀ
phile under the mild Pdꢀcatalyzed amination conditions deꢀ
scribed in this report when compared directly to other comꢀ
mon aryl electrophiles. In addition, the direct amination of a
phenol by the in situ formation of an aryl fluorosulfonate from
a phenol and sulfuryl fluoride followed by subsequent CꢀN
bond forming amination is described. These aminations are
immediately amenable to commercial scale preparations of
complex molecules. The high activity of the aryl fluorosulꢀ
fonate in palladium and nickel catalyzed coupling chemistry
allows for the use of widely available, generic ligands. Finalꢀ
ly, the reappropriation of the structural fumigant sulfuryl fluoꢀ
ride as an activating group for crossꢀcoupling allows for the
most economical means of aminating phenols. In many cases,
we find that these aminations are economically advantaged
and have a smaller environmental footprint than the correꢀ
sponding coupling of aryl halides. Current work at Dow
Chemical continues to explore couplings of aryl fluorosulꢀ
(8) (a) Roth, G.P.; Fuller, C. E.; J. Org. Chem. 1991, 56, 3493ꢀ
3496. (b) Roth, G. P.; Thomas, J. A. Tetrahedron Lett. 1992, 33,
1959ꢀ1962. (c) McGuire, M. A.; Sorenson, E.; Owings, F. W.; Resꢀ
nick, T. M.; Fox, M.; Baine, N. H.; J. Org, Chem. 1994, 59, 6683ꢀ
6686. (d) Clark, W. M.; TicknerꢀEldridge, A. M.; Huang, G. K.; Pridꢀ
gen, L. N.; Olsen, M. A.; Mills, R. J.; Lantos, I.; Baine, N. H. J. Am.
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