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Synlett
S. Ma, P. H. Toy
Cluster
gin of this increased efficiency, as well as applying 6 and
heterogeneous analogues of it to other reactions, are cur-
rently under way, and the results of these efforts will be re-
ported in due course.
(6) Lu, J.; Toy, P. H. Synlett 2011, 1723.
(
7) For reports regarding DMAP attached to basic polyethylene-
imines in ester hydrolysis reactions, see: (a) Hierl, M. A.;
Gamson, E. P.; Klotz, I. M. J. Am. Chem. Soc. 1979, 101, 6020.
(
b) Delaney, E. J.; Wood, L. E.; Klotz, I. M. J. Am. Chem. Soc. 1982,
04, 799.
8) (a) Leung, P. S.-W.; Teng, Y.; Toy, P. H. Org. Lett. 2010, 12, 4996.
b) Lu, J.; Toy, P. H. Synlett 2011, 3085. (c) Teng, Y.; Lu, J.; Toy, P.
1
(
Acknowledgement
(
H. Chem. Asian J. 2012, 7, 351. (d) Lu, J.; Toy, P. H. Pure Appl.
Chem. 2013, 85, 543. (e) Xia, X.; Toy, P. H. Beilstein J. Org. Chem.
This research was supported financially by the University of Hong
Kong and the Research Grants Council of the Hong Kong S. A. R., P. R.
of China (Project No. HKU 705510P).
2014, 10, 1397. (f) Derible, A.; Yang, Y.-C.; Toy, P. H.; Becht, J.-
M.; Le Drian, C. Tetrahedron Lett. 2014, 55, 4331. (g) Xia, X.; Toy,
P. H. Synlett 2015, 26, 1737.
(
9) See Supporting Information for details.
Supporting Information
(
10) General Procedure for Esterification Reactions
Supporting information for this article is available online at
Acylating reagent 7 (1.2 equiv) was slowly added dropwise into
a stirred solution of alcohol 8 (1.0 equiv) and polymer 6 in dry
toluene (30 mL). The reaction mixture was stirred at r.t., and
when TLC indicated that 8 had been completely consumed, the
reaction mixture was slowly added dropwise into hexane (150
mL). The resulting precipitate was filtered off, and the filtrate
was washed with sat. aq Na CO (50 mL). The organic layer was
http://dx.doi.org/10.1055/s-0035-1560415.
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References and Notes
(1) Höfle, G.; Steglich, W.; Vorbrüggen, H. Angew. Chem., Int. Ed.
2
3
Engl. 1978, 17, 569.
washed with brine (50 mL) and dried over anhydrous MgSO4,
and concentrated under reduced pressure to afford product
(2) For selected recent examples, see: (a) Cotanda, P.; Lu, A.;
Patterson, J. P.; Petzetakis, N.; O’Reily, R. K. Macromolecules
1
ester 9 in an essentially pure state according to H NMR analy-
2012, 45, 2377. (b) Khamatnurova, T. V.; Johnson, M.; Santana,
sis. The collected precipitate was dissolved MeOH (8 mL), and
was slowly added dropwise to a vigorously stirred solution of
D.; Bazzi, H. S.; Bergbreiber, D. E. Top Catal. 2014, 57, 1438.
(c) Zhen, Y.; Lin, H.; Wang, S.; Tao, M. RSC Adv. 2014, 4, 26122.
0.1 N NaOH dissolved in MeOH (100 mL) at 0 °C. The resulting
(d) Okuno, Y.; Isomura, S.; Sugamata, A.; Tamahori, K.;
light yellow precipitate was filtered, washed with MeOH (40
mL), and dried under reduced pressure for reuse in the next
reaction.
Fukuhara, A.; Kashiwagi, M.; Kitagawa, Y.; Kasai, E.; Takeda, K.
ChemSusChem 2015, 8, 1629.
(
3) For a very recent report regarding the use of a porous solid
polymeric acid catalyst in esterification reactions between car-
boxylic acids and alcohols, see: Kim, Y.-H.; Han, J.; Jung, B. Y.;
Baek, H.; Yamada, Y. M. A.; Uozumi, Y.; Lee, Y.-S. Synlett 2016,
1
-Phenylethyl Acetate (9Aa)
1
H NMR (400 MHz, CDCl ): δ = 1.49 (d, 3 H, J = 6.8 Hz), 1.98 (s, 3
3
H), 5.86 (q, 1 H, J = 6.8 Hz), 7.22–7.33 (m, 5 H). 13C NMR (100
MHz, CDCl ): δ = 21.0. 22.0, 72.0, 125.9 (2 C), 127.6, 128.3 (2 C),
3
27, 29.
1
69.8. LRMS: m/z calcd for C10H12O : 164.1; found: 164.1.
2
(4) Lu, J.; Toy, P. H. Synlett 2011, 659.
(
11) Sakakura, A.; Kawajiri, K.; Ohkubo, T.; Kosugi, Y.; Ishihara, K.
(5) Kwong, C. K.-W.; Huang, R.; Zhang, M.; Shi, M.; Toy, P. H. Chem.
Eur. J. 2007, 13, 2369.
J. Am. Chem. Soc. 2007, 129, 14775.
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–D