4
Tetrahedron Letters
Chinese U. 2003, 24, 1618–1620; (b) Ghatak, A.; Becker, F. F.;
Banik, B. K. Tetrahedron Lett. 2000, 41, 3793–3796.
In conclusion, allySmBr-induced reductive coupling of
carbonyl compounds has been developed. MeOH and H2O were
found to be effective additive being able to switch the reactivity
of allylSmBr. Thus the highly nucleophilic allylSmBr could
function as good reductive coupling or reducing reagent in their
3.
(a) Tu, Y. W.; Zhou, L. J.; Yin, R. F.; Lv. X.; Flowers, R. A. II;
Choquette, K. A.; Liu, H. L.; Niu, Q. S.; Wang, X. X. Chem.
Commun. 2012, 48, 11026–11028. (b) Shen, M. M.; Tu, Y. W.;
Xie, G. Q.; Niu, Q. S.; Mao H.; Xie, T. T.; Flowers II, R. A.; Lv,
X.; Wang, X. X. J. Org. Chem. 2015, 80, 52–61. (c) Yin, R. F.;
Zhou, L. J.; Liu, H. L.; Mao, H.; Lv, X.; Wang, X. X. Chin. J.
Chem. 2013, 31, 143–148.
presence. Since MeOH and H2O are greener additives than
HMPA,8,
the reactivity of allylSmBr switched by these
3a-b
additives is worthy of further study so as to find more
interesting applications in organic synthesis.
4.
5.
(a) Hu, Y. Y.; Zhao, T.; Zhang, S. L. Chem. Eur. J. 2010, 16,
1697–1705. (b) Li, Y.; Hu, Y. Y.; Zhang, S. L. Chem. Commun.
2013, 49, 10635–10637.
(a) Hoz, S.; Yacovan, A.; Bilkis, I. J. Am. Chem. Soc. 1996, 118,
261−262; (b) Chopade, P. R.; Prasad, E.; Flowers, R. A., II. J.
Am.Chem. Soc. 2004, 126, 44−45; (c) Procter, D. J.; Flowers, R.
A.; Skrydstrup, T. Organic Synthesis Using Samarium Diiodide:
A Practical Guide; Royal Society of Chemistry: London, 2010.
General Procedure for the pinacol coupling of aldehydes and
ketones to form the diols (3). An oven-dried 50 mL two-necked
flask containing finely powdered samarium (0.375 g, 2.5 mmol)
was evacuated and backfilled with N2 for three times. Under a
positive pressure of nitrogen, a solution of allylBr (0.12 mL, 1.4
mmol) in dry THF (10 mL) was added via a syringe, and then
added a grain of iodine. The mixture was allowed to stir at room
temperature for 1 h (the mixture was deep purple). MeOH or H2O
was then added followed by addition of a solution of aldehydes or
ketones (1 mmol) in dry THF (1 mL) via a syringe. The reaction
mixture was stirred at room temperature until the completion of
the reaction (monitored by TLC). The reaction was quenched by a
sat. potassium sodium tartrate solution (5 mL). The mixture was
extracted by ethyl acetate (3 × 15 mL). The combined extracts
were washed with brine, dried over Na2SO4, and concentrated
under reduced pressure. The residue was purified by
chromatography on silica gel (200–300 mesh) using
Acknowledgments
This work was financially supported by the Natural Science
Foundation of Zhejiang Province (No. LY14B020001) and
National Natural Science Foundation of China (No. 21202152).
6.
Supplementary data
Supplementary data (the spectral data and the H NMR, 13C
1
NMR spectra of 3) associated with this article can be found in the
online version.
References and notes
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v : v) as eluent to afford the
7.
8.
2.
(a) Yu, M.-X.; Zhang, Y.-M. Synthesis of Homoallyl Alcohol by
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