ORGANIC
LETTERS
2
007
Vol. 9, No. 19
785-3788
Palladium-Catalyzed Silylation of Aryl
Chlorides with Hexamethyldisilane
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Eric McNeill, Timothy E. Barder, and Stephen L. Buchwald*
Department of Chemistry, Massachusetts Institute of Technology,
Cambridge, Massachusetts 02139
Received June 26, 2007
ABSTRACT
A method for the palladium-catalyzed silylation of aryl chlorides has been developed. The method affords desired product in good yield, is
tolerant of a variety of functional groups, and provides access to a wide variety of aryltrimethylsilanes from commercially available aryl
chlorides. Additionally, a one-pot procedure that converts aryl chlorides into aryl iodides has been developed.
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Classically, arylsilanes have been synthesized from the
corresponding aryl halide by lithium/halogen exchange or
generation of the Grignard reagent, followed by nucleophilic
trochemical methods. Notably, Goossen recently published
a useful method for the synthesis of aryltrimethylsilanes via
Pd catalysis with unhindered aryl bromides and hexameth-
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attack on a silicon electrophile. This method, however, is
yldisilane. Additionally, Tsuji reported the silylation of
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limited to arenes which lack base-sensitive functional groups.
Beginning in the 1970s, a number of groups reported on the
synthesis of arylsilanes by coupling aryl bromides, aryl
PhCl; however, this was the only aryl chloride employed.
As aryl chlorides are generally less expensive and more
readily available than aryl bromides, we initiated an inves-
tigation on the coupling of hexamethyldisilane with both
hindered and unhindered substrates. Herein, we report a
method for the palladium-catalyzed silylation of aryl chlo-
rides with hexamethyldisilane as well as an one-pot proce-
dure to convert aryl chlorides into aryl iodides.
iodides, aryl nitriles, or aroyl chlorides with disilanes or
hydrosilanes using transition-metal catalysis2
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and elec-
(
1) (a) Luli n´ ski, S.; Serwatowski, J. J. Org. Chem. 2003, 68, 9384-
9
388. (b) Manoso, A. S.; Ahn, C.; Soheile, A.; Handy, C. J.; Correia, R.;
Seganish, W. M.; DeShong, P. J. Org. Chem. 2004, 69, 8305-8314 and
references therein.
Biaryl ligands (Figure 1) have shown tremendous utility
in cross-coupling reactions for the formation of carbon-
carbon, carbon-nitrogen, and carbon-oxygen bonds. We
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14
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(
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(14) Recent papers that utilize biaryl phosphines in C-O, C-N, and
C-C bond forming processes: (a) Burgos, C. H.; Barder, T. E.; Huang,
X.; Buchwald, S. L. Angew. Chem., Int. Ed. 2006, 45, 4321-4326. (b)
Anderson, K. W.; Tundel, R. E.; Ikawa, T.; Altman, R. A.; Buchwald, S.
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(
Chem. 1993, 446, 135-138.
(
(
(
(
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0.1021/ol701518f CCC: $37.00
© 2007 American Chemical Society
Published on Web 08/18/2007