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3
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33646944179
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and citations therein
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Yang A., Butela H., Deng K., Doubleday M.D., and Cohen T. Tetrahedron 62 (2006) 6526-6535 and citations therein
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(2006)
Tetrahedron
, vol.62
, pp. 6526-6535
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Yang, A.1
Butela, H.2
Deng, K.3
Doubleday, M.D.4
Cohen, T.5
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7
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70649102538
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In the earliest reports of the reductive lithiation of phenyl thioethers, there were several examples in which a sub-stoichiometric quantity of naphthalene was used along with a stoichiometric quantity of lithium metal: see Ref. 1a and (a) Screttas, C. G.; Micha-Screttas, M. J. Org. Chem. 1979, 44, 713-719. More recently, Yus's group has extensively utilized a form of the catalytic method in which a large excess of lithium is used along with a catalytic amount of the aromatic, usually naphthalene or p,p′-di-tert-butylbiphenyl: (b) Yus, M., In The Chemistry of Organolithium Compounds, Rappoport, Z. Marek, I., Ed.; Wiley: Chichester, 2004; Part 2, Chapter 11; (c) Ramón, D. J.; Yus, M. Eur. J. Org. Chem. 2000, 225-237.
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In the earliest reports of the reductive lithiation of phenyl thioethers, there were several examples in which a sub-stoichiometric quantity of naphthalene was used along with a stoichiometric quantity of lithium metal: see Ref. 1a and (a) Screttas, C. G.; Micha-Screttas, M. J. Org. Chem. 1979, 44, 713-719. More recently, Yus's group has extensively utilized a form of the catalytic method in which a large excess of lithium is used along with a catalytic amount of the aromatic, usually naphthalene or p,p′-di-tert-butylbiphenyl: (b) Yus, M., In The Chemistry of Organolithium Compounds, Rappoport, Z. Marek, I., Ed.; Wiley: Chichester, 2004; Part 2, Chapter 11; (c) Ramón, D. J.; Yus, M. Eur. J. Org. Chem. 2000, 225-237.
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13
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0038250183
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Shook C.A., Romberger M.L., Jung S.-H., Xiao M., Sherbine J.P., Zhang B., Lin F.-T., and Cohen T. J. Am. Chem. Soc. 115 (1993) 10754-10773
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(1993)
J. Am. Chem. Soc.
, vol.115
, pp. 10754-10773
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Shook, C.A.1
Romberger, M.L.2
Jung, S.-H.3
Xiao, M.4
Sherbine, J.P.5
Zhang, B.6
Lin, F.-T.7
Cohen, T.8
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15
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0006553959
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Cabral J.A., Cohen T., Doubleday W.W., Duchelle E.F., Fraenkel G., Guo B.-S., and Yü S.H. J. Org. Chem. 57 (1992) 3680-3684
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(1992)
J. Org. Chem.
, vol.57
, pp. 3680-3684
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Cabral, J.A.1
Cohen, T.2
Doubleday, W.W.3
Duchelle, E.F.4
Fraenkel, G.5
Guo, B.-S.6
Yü, S.H.7
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21
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0001727276
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Cohen T., Sherbine J.P., Matz J.R., Hutchins R.R., McHenry B.M., and Willey P.R. J. Am. Chem. Soc. 106 (1984) 3245-3252
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(1984)
J. Am. Chem. Soc.
, vol.106
, pp. 3245-3252
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Cohen, T.1
Sherbine, J.P.2
Matz, J.R.3
Hutchins, R.R.4
McHenry, B.M.5
Willey, P.R.6
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34
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0032191024
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Manteca I., Etxarri B., Ardeo A., Arrasate S., Osante I., Sotomayor N., and Lete E. Tetrahedron 54 (1998) 12361-12378
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(1998)
Tetrahedron
, vol.54
, pp. 12361-12378
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Manteca, I.1
Etxarri, B.2
Ardeo, A.3
Arrasate, S.4
Osante, I.5
Sotomayor, N.6
Lete, E.7
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42
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37049076294
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Barluenga J., Fernández-Simón J.L., Concellón J.M., and Yus M. J. Chem. Soc., Chem. Commun. (1987) 915-916
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(1987)
J. Chem. Soc., Chem. Commun.
, pp. 915-916
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Barluenga, J.1
Fernández-Simón, J.L.2
Concellón, J.M.3
Yus, M.4
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50
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33644751690
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recent papers reporting the use of LDBB: Refs. 2, 7a and 8a and
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recent papers reporting the use of LDBB: Refs. 2, 7a and 8a and. Merten J., Hennig A., Schwab P., Frohlich R., Tokalov S.V., Gutzeit H.O., and Metz P. Eur. J. Org. Chem. (2006) 1144-1161
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(2006)
Eur. J. Org. Chem.
, pp. 1144-1161
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Merten, J.1
Hennig, A.2
Schwab, P.3
Frohlich, R.4
Tokalov, S.V.5
Gutzeit, H.O.6
Metz, P.7
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55
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3042841597
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Cooksey J., Gunn A., Kocienski P.J., Kuhl A., Uppal S., Christopher J.A., and Bell R. Org. Biomol. Chem. 2 (2004) 1719-1731
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(2004)
Org. Biomol. Chem.
, vol.2
, pp. 1719-1731
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Cooksey, J.1
Gunn, A.2
Kocienski, P.J.3
Kuhl, A.4
Uppal, S.5
Christopher, J.A.6
Bell, R.7
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57
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70649095633
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note
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In some cases this was due to the sensitivity of the product of electrophile capture to the acid that was used to remove the dimethylaminonaphthalene byproduct: Brockunier, L. L., MS Thesis, University of Pittsburgh, 1988, p 21. However, even when the product is not acid-sensitive, some preliminary trials had indicated that LDBB gave superior results.
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49049131007
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note
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3,11 However, occasional irreproducibility and poor yields (for one literature example, see: Paquette, L. A.; Horn, K. A.; Wells, G. J. Tetrahedron Lett. 1982, 23, 259-262) led to speculation that lower temperatures may lead to better results and starting in 1999, the temperature of -55 °C was generally aimed for during the generation of LDMAN, although careful temperature control was not generally sought; apparently the first example was the lower temperature to prepare LDMAN only for the synthesis of 24 in: Chen, F.; Mudryk, B.; Cohen, T. Tetrahedron 1999, 55, 3291-3304. However, most other groups that have reported the use of LDMAN are still using the original recipe.
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There may be automatic temperature controllers that can maintain the required narrow range, but we are unaware of any at this time.
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70649114013
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General procedure for the reductive lithiation with LDMAN; To a three-neck round bottomed flask, equipped with a magnetic stirrer, argon inlet and a rubber septum was added 40 mL of dry THF. The flask was cooled to -55 °C. Lithium ribbon was prepared by scraping the dark oxide coating off of the surface while it was immersed in fresh mineral oil. The shiny metal was dipped into dry hexane in order to remove the oil and then weighed (0.1852 g, 0.0268 mol) in a tared beaker containing mineral oil. The metal was sliced into small pieces while it was still immersed in mineral oil. The lithium pieces were dipped again in hexane prior to the addition to the flask. Then DMAN (4.9 mL, 0.030 mol) was added quickly via syringe at -55 °C. A green color appeared in less than two minutes and became deep green in less than 5 min. The reaction mixture was stirred for 5 h at -55 ± 3 °C, and the resulting LDMAN solution was suitable for reductive lithiation of 0.0127 mol of substrate.
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