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For recent reviews, see: G. Zanoni, F. Castronovo, M. Franzini, G. Vidari, and E. Giannini Chem. Soc. Rev. 32 2003 115
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D.A. Evans, M.C. Kozlowski, J.A. Murry, C.S. Burgey, K.R. Campos, B.T. Connell, and R.J. Staples J. Am. Chem. Soc. 121 1999 669
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Evans, D.A.1
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Campos, K.R.5
Connell, B.T.6
Staples, R.J.7
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9
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0033551875
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H. Matsunaga, U. Yamada, T. Ide, T. Ishizuka, and T. Kunieda Tetrahedron: Asymmetry 10 1999 3095
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Tetrahedron: Asymmetry
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Matsunaga, H.1
Yamada, U.2
Ide, T.3
Ishizuka, T.4
Kunieda, T.5
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13
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0032540647
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D.A. Evans, C.S. Burgey, N.A. Paras, T. Vojkovsky, and S.W. Tregay J. Am. Chem. Soc. 120 1998 5824
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33748726159
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D.A. Evans, J.A. Murry, P. von Matt, R.D. Norcross, and S.J. Miller Angew. Chem., Int. Ed. 34 1995 798
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Evans, D.A.1
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Von Matt, P.3
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Miller, S.J.5
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19
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0033936085
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for an excellent comprehensive account on asymmetric Diels-Alder, aldol, ene, and Michael additions see: J.S. Johnson, and D.A. Evans Acc. Chem. Res. 33 2000 325
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Acc. Chem. Res.
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Johnson, J.S.1
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20
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33749535618
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H. Maheswaran, K.L. Prasanth, G.G. Krishna, K. Ravikumar, B. Sridhar, and M. Lakshmi Kantam Chem. Commun. 39 2006 4066
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Maheswaran, H.1
Prasanth, K.L.2
Krishna, G.G.3
Ravikumar, K.4
Sridhar, B.5
Lakshmi Kantam, M.6
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21
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0018359796
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Absolute configuration of the aldol adducts are tentatively assigned (R) or (S) by comparison with relative signs of the specific rotations data of aldol with those reported for 5a and 5g as reference compounds, see: T. Sugasawa, and T. Toyoda Tetrahedron Lett. 16 1979 1423 By this analogy, a (+)-aldol adduct is tentatively assigned as the (R)-isomer while a (-)-aldol adduct is assigned as the (S)-isomer
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(1979)
Tetrahedron Lett.
, vol.16
, pp. 1423
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Sugasawa, T.1
Toyoda, T.2
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22
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33646795005
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S. Kiyooka, Y. Takeshita, Y. Tanaka, T. Higaki, and Y. Wada Tetrahedron Lett. 47 2006 4453
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Kiyooka, S.1
Takeshita, Y.2
Tanaka, Y.3
Higaki, T.4
Wada, Y.5
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23
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10844258853
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For a recent review on double catalytic activation (DCA) protocol: see S. Kanemasa, and K. Ito Eur. J. Org. Chem. 2004 4741
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(2004)
Eur. J. Org. Chem.
, pp. 4741
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Kanemasa, S.1
Ito, K.2
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24
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12944251474
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Fluoride anions are excellent catalysts for Mukaiyama aldol reaction: see E. Nakamura, M. Shimizu, I. Kuwajima, J. Sakata, K. Yokoyama, and R. Noyori J. Org. Chem. 48 1983 932
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(1983)
J. Org. Chem.
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, pp. 932
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Nakamura, E.1
Shimizu, M.2
Kuwajima, I.3
Sakata, J.4
Yokoyama, K.5
Noyori, R.6
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27
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0003438540
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3rd ed. Cornell University Press New York
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Fluoride anions show an extremely high affinity for the silicon atom due to high homolytic bond energy; see: L. Pauling The Nature of Chemical Bond 3rd ed. 1960 Cornell University Press New York Chapter 3. This property enables its routine use in organic synthesis as deprotecting agents for silyl groups
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(1960)
The Nature of Chemical Bond
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Pauling, L.1
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28
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20944436033
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To the best of our knowledge until now there is no report for the enantioselective direct aldol reaction of aromatic aldehydes and methylvinylketone (MVK) under catalytic conditions. For direct aldol reaction of aliphatic aldehydes with methylvinylketone (MVK); see: B.M. Trost, S. Shin, and J.A. Sclafani J. Am. Chem. Soc. 127 2005 8602
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(2005)
J. Am. Chem. Soc.
, vol.127
, pp. 8602
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Trost, B.M.1
Shin, S.2
Sclafani, J.A.3
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29
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77956181608
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For direct aldol reaction of methylvinylketone (MVK) using catalyst 2, better yields and enantioselectivities were obtained in methanol. In contrast, for catalyst 1, the best solvent for the reaction is DMF. It should be noted that solvent independent enantioreversal with identical sign of the specific rotation occurs in both the solvents (DMF and MeOH) with catalysts 1 and 2
-
For direct aldol reaction of methylvinylketone (MVK) using catalyst 2, better yields and enantioselectivities were obtained in methanol. In contrast, for catalyst 1, the best solvent for the reaction is DMF. It should be noted that solvent independent enantioreversal with identical sign of the specific rotation occurs in both the solvents (DMF and MeOH) with catalysts 1 and 2.
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30
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53849129256
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It is a popular misconception that the (+)-sparteine is not a natural product; however, although more narrowly distributed than its better known and commercially available antipode (-)-sparteine. It is well known that (+)-sparteine is biosynthesized by numerous plant species. Traditionally, (+)-sparteine has been most conveniently obtained from natural (±)-lupanine (2-oxosparteine), extracted from the seeds of Lupinus albus, by classical resolution followed by reduction of the resulting (-)-lupanine. For references see N.R. Norcross, J.P. Melbardis, M.F. Solera, M.A. Sephton, C. Kilner, L.N. Zakharov, P.C. Astles, S.L. Warriner, and P.R. Blakemore J. Org. Chem. 73 2008 7939
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J. Org. Chem.
, vol.73
, pp. 7939
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Norcross, N.R.1
Melbardis, J.P.2
Solera, M.F.3
Sephton, M.A.4
Kilner, C.5
Zakharov, L.N.6
Astles, P.C.7
Warriner, S.L.8
Blakemore, P.R.9
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32
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77956188552
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The cost of (+)-sparteine (as pachycarpine) is ca. three times greater than that typical for (-)-sparteine
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The cost of (+)-sparteine (as pachycarpine) is ca. three times greater than that typical for (-)-sparteine.
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33
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77956185383
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More recently, (+)-sparteine itself has been discovered to be a minor alkaloid of Lupinus albus, see: W. Wysocka Sci. Legumes 2 1995 137 140
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(1995)
Sci. Legumes
, vol.2
, pp. 137-140
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Wysocka, W.1
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35
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0032022331
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S. Lopez, I. Muravyov, S.R. Pulley, and S.W. Keller Acta Crystallogr., Sect. C 54 1998 355
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(1998)
Acta Crystallogr., Sect. C
, vol.54
, pp. 355
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Lopez, S.1
Muravyov, I.2
Pulley, S.R.3
Keller, S.W.4
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37
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77956189131
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Degree of distortion from the planarity is reflected by the magnitude of dihedral angle between the MN2 plane and MCl2 plane, which is 67.0°and 81.3° for 1 and 2, respectively
-
Degree of distortion from the planarity is reflected by the magnitude of dihedral angle between the MN2 plane and MCl2 plane, which is 67.0°and 81.3° for 1 and 2, respectively.
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-
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41
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0001480422
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P.R. Raithby, G.P. Shields, F.H. Allen, and W.D.S. Motherwell Acta Crystallogr., Sect. B 56 2000 444
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(2000)
Acta Crystallogr., Sect. B
, vol.56
, pp. 444
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Raithby, P.R.1
Shields, G.P.2
Allen, F.H.3
Motherwell, W.D.S.4
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42
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77956183790
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note
-
ij represents corresponding crystallographically observed bond angles. The atoms are labelled (1-4) in the order of decreasing bond lengths so that the corresponding bond angles between displacement vectors lie in the same asymmetric unit of the vector space defined by symmetry coordinates.
-
-
-
-
43
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77956183122
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-
note
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1) = 266.4°.
-
-
-
-
45
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77956182946
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The balance of electronic and steric factors in 1 and 2 complexes are directly reflected in the asymmetry of M-N bond lengths in their X-ray structures. The Cu-N1 facing the endo-ring has a shorter Cu-N bond length (Cu-N1 = 2.003 (3) Å) compared to 2.021 (3) Å for Cu-N2 facing the exo-ring. In complex 2, both Ni-N1 and Ni-N2 bond distances correspond to a more symmetric configuration with 2.032 (4) Å and 2.027 (4) Å, respectively, which is slightly longer than those observed in complex 1
-
The balance of electronic and steric factors in 1 and 2 complexes are directly reflected in the asymmetry of M-N bond lengths in their X-ray structures. The Cu-N1 facing the endo-ring has a shorter Cu-N bond length (Cu-N1 = 2.003 (3) ) compared to 2.021 (3) for Cu-N2 facing the exo-ring. In complex 2, both Ni-N1 and Ni-N2 bond distances correspond to a more symmetric configuration with 2.032 (4) and 2.027 (4), respectively, which is slightly longer than those observed in complex 1.
-
-
-
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47
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6344238979
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B. Jasiewicz, E. Sikorska, I.V. Khmelinskii, B. Warzajtis, U. Rychlewska, W.l. Boczon, and M. Sikorski J. Mol. Struct. 707 2004 89
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(2004)
J. Mol. Struct.
, vol.707
, pp. 89
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Jasiewicz, B.1
Sikorska, E.2
Khmelinskii, I.V.3
Warzajtis, B.4
Rychlewska, U.5
Boczon, W.L.6
Sikorski, M.7
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49
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0037293456
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Y.M. Lee, M.-A. Kwon, S.K. Kang, J.H. Jeong, and S.-N. Choi Inorg. Chem. Commun. 6 2003 197
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(2003)
Inorg. Chem. Commun.
, vol.6
, pp. 197
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Lee, Y.M.1
Kwon, M.-A.2
Kang, S.K.3
Jeong, J.H.4
Choi, S.-N.5
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50
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0000016277
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The rms overlay of X-ray structures (1 and 2) was obtained by calculations involving published X-ray crystal structure data (see Ref. 13) using Mercury software (Version 1.4.1). For further details see: I. Bruno, J.J.C. Cole, P.R. Edgington, M.K. Kessler, C.F. Macrae, P. McCabe, J. Pearson, and R. Taylor Acta. Cryst., Sect. B 58 2002 389 397
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(2002)
Acta. Cryst., Sect. B
, vol.58
, pp. 389-397
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Bruno, I.1
Cole, J.J.C.2
Edgington, P.R.3
Kessler, M.K.4
MacRae, C.F.5
McCabe, P.6
Pearson, J.7
Taylor, R.8
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