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10 The reaction of 1c under light-shielding conditions provided
the same yield along with that under optimized conditions,
which clearly pointed out that the present Kharasch reaction
was signicantly facilitated by both heating and the addition
of NaOAc.
11 Aer the generation of the desired product (2l), the bromine is
eliminated by the electron-donating property of the methoxy
group to form the cation intermediate (B) and the
subsequent nucleophilic attack by an acetate anion
produces the intermediate C. The following elimination of
Notes and references
1 Recent selected papers: (a) W. T. Eckenhoff and T. Pintauer,
Catal. Rev.: Sci. Eng., 2010, 52, 1–59; (b) T. Pintauer, Eur. J.
Inorg. Chem., 2010, 17, 2449–2460; (c) C. Ricardo and
T. Pintauer, Chem. Commun., 2009, 3029–3031; (d)
K. Thommes, G. Kiefer, R. Scopelliti and K. Severin, Angew.
Chem., Int. Ed., 2009, 48, 8115–8119; (e) J. M. Munoz-
Molina, T. R. Belderrain and P. J. Perez, Eur. J. Inorg.
Chem., 2011, 21, 3155–3164.
˜
´
the hydrochloride affords 4. Alternatively,
B can be
2 (a) M. S. Kharasch, E. V. Jensen and W. H. Urry, Science, 1945,
102, 128; (b) M. S. Kharasch, E. V. Jensen and W. H. Urry, J.
Am. Chem. Soc., 1946, 68, 154–155; (c) M. S. Kharasch,
E. V. Jensen and W. H. Urry, J. Am. Chem. Soc., 1947, 69,
1100–1105; (d) M. S. Kharasch, O. Reinmuth and
W. H. Urry, J. Am. Chem. Soc., 1947, 67, 1105–1100.
transformed into D in association with dehydrochlorination
and the subsequent addition of the acetate anion to D
affords 4
3 The trichloromethyl group is easily hydrolyzed to the
corresponding carboxylic acid and can be efficiently
transformed into the gem-dichloromethyl functionality as an
useful equivalent of the aldehyde. We have also developed
the Pt/C-catalyzed chemoselective hydrogenation method of
the trichloromethyl group to prepare the gem-dichloromethyl
functionality. The related references are cited in the following
paper, see: T. Imanishi, Y. Fujiwara, Y. Sawama, Y. Monguchi
and H. Sajiki, Adv. Synth. Catal., 2012, 354, 771–776.
4 F.-H. Wu and W.-Y. Huang, J. Fluorine Chem., 2001, 110, 59–61.
5 H. Yorimitsu, H. Shinokubo, S. Matsubara and K. Oshima, J.
Org. Chem., 2001, 66, 7776–7785.
6 For the reviews, see: (a) R. A. Gossage, L. A. Van de Kuil and
.
G. V. Koten, Acc. Chem. Res., 1998, 31, 423–431; (b) K. Severin, 12 The detail of the optimization was depicted in ESI.†
Curr. Org. Chem., 2006, 10, 217–224.
7 For the recent selected reports using the transition metals,
13 J. A. Gladysz, D. P. Curran and I. T. Horvath, Handbook of
Fluorous Chemistry, Wiley-VCH, Weinheim, 2004.
see: (a) F. Simal, S. Sebille, A. Demonceau, A. F. Noels, 14 The elemental iron and copper metals were also known to
ˇ
ˇ
R. Nunez, M. Abad, F. Teixidor and C. Vinas, Tetrahedron
Lett., 2000, 41, 5347–5351; (b) D. Motoda, H. Kinoshita,
H. Shinokubo and K. Oshima, Adv. Synth. Catal., 2002, 344,
261–265; (c) L. Quebatte, R. Scopelliti and K. Severin,
facilitate the ATRA of CCl4 and CCl3Br to olens. See:
F. Bellesia, L. Forti, F. Ghel and U. M. Pagnoni, Synth.
Commun., 1997, 27, 961–971. The present reactions could
be promoted by the use of the various combinations of
polyhalomethanes, olens, NaOAc and DMA each
purchased from variety of suppliers (e.g., Aldrich, Wako
Pure Chemical Industries, Tokyo Chemical Industry etc.),
although the promotion by the trace of metal impurities
cannot be perfectly ruled out.
´
Angew. Chem., Int. Ed., 2004, 43, 1520–1524; (d) A. E. Dıaz-
Alvarez, P. Crochet, M. Zablocka, C. Duhayon, V. Cadierno
and J.-P. Majoral, Eur. J. Inorg. Chem., 2008, 786–794; (e)
L. Cao and C. Li, Tetrahedron Lett., 2008, 49, 7380–7382; (f)
K. Parkhomenko, L. Barloy, J.-B. Sortais, J.-P. Djukic and
´
M. Pfeffer, Tetrahedron Lett., 2010, 51, 822–825; (g) 15 Acyl hypobromite plays the role as a good radical initiator,
W. T. Eckenhoff and T. Pintauer, Dalton Trans., 2011, 40,
4909–4917; (h) J. R. Khusnutdinova, N. P. Rath and
see: P. S. Skell and D. D. May, J. Am. Chem. Soc., 1983, 105,
3999–4008.
L. M. Mirica, Angew. Chem., Int. Ed., 2011, 50, 5532–5536; 16 1,2-Dimethoxyethane and its related compounds, which can
(i) J. D. Nguyen, J. W. Tucker, M. D. Konieczynska and
C. R. J. Stephenson, J. Am. Chem. Soc., 2011, 133, 4160–
4163; (j) C.-J. Wallentin, J. D. Nguyen, P. Finkbeiner and
C. R. J. Stephenson, J. Am. Chem. Soc., 2012, 134, 8875–8884.
8 X.-B. Wang, H.-K. Woo and L.-S. Wang, J. Phys. Chem. A, 2006,
110, 5047–5050.
form bidentate metal complexes are known to be transformed
into various radical species. Sodium cation complex derived
from NaOAc and 1,2-dimethoxyethane might facilitate the
formation of various radical species and the following ATRA
of polyhaloalkanes to olens, see: (a) R. Thissen, C. Alcaraz,
O. Dutuit, P. Mourgues, J. Chamot-Rooke and H. E. Audier,
J. Phys. Chem. A, 1999, 103, 5049–5054; (b) H. Liu, J. Sun and
S. Yang, J. Phys. Chem. A, 2003, 107, 5681–5691.
9 M. Heintz, G. Leny and J. Y. Nedelec, Tetrahedron Lett., 1984,
25, 5767–5768.
8660 | RSC Adv., 2014, 4, 8657–8660
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