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The application of alkaline metal(Ca, Sr, Ba) complex as catalyst in organic chemistry. 2010.12.04 张文全. introduction.
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The application of alkaline metal(Ca, Sr, Ba) complex as catalyst in organic chemistry 2010.12.04 张文全
introduction Alkaline earth metals are very attractive because they are abundant and ubiquitous elements in nature and form safe compounds compared with other heavy transition metals. However, their positive use as catalysts in asymmetric synthesis is still limited. Their strong Brønsted basicity and mild Lewis acidity can influence their catalytic activity, as well as chiral modification of a complex in a positive manner.
calcium The application of calcium complex in organic chemistry will show follow
First example of an optically active calcium catalyst Baylis–Hillman Reaction 62 yield% 56 ee% Shiro Ikegami, Tetrahedron Letters 41 (2000) 2165
Michael Reactions G. Kumaraswamy, Tetrahedron Letters 42 (2001) 8515
18-96ee% 50-quant yield% Shu Kobayashi, Angew. Chem. Int. Ed. 2009, 48, 9117
ligand real catalyst Shu Kobayashi, J. AM. CHEM. SOC. 2010, 132, 7890
Shu Kobayashi, J. AM. CHEM. SOC. 2007, 129, 5364 Shu Kobayashi, J. AM. CHEM. SOC. 2008, 130, 13321 Shu Kobayashi, O.L. 2008, Vol. 10, No. 5, 807
Two Possible Reaction Mechanisms of the [3 + 2] Cycloaddition Reaction
cis/trans=2/1 so stepwise is possible
Friedel-Craft Reaction ArH = electrion-rich Aromatic Meike Niggemann, Angew. Chem. Int. Ed. 2010, 49, 3684
Mannich Reaction cat: Kazuaki Ishihara, Angew. Chem. Int. Ed. 2010, 49, 3823
Aliphatic N-Boc imine can react, good yield but low ee Shu Kobayashi, J. Org. Chem. 2010, 75, 963
epoxidation G. Kumaraswamy, Tetrahedron: Asymmetry 14 (2003) 3797
Hydroarylation of Alkenes electrion-rich Aromatic etc Meike Niggemann, Chem. Eur. J. 2010, 16, 11246
Hydroamination Michael S. Hill, J. AM. CHEM. SOC. 2005, 127, 2042
aminoalkene product Time(h) Temp.(oC) Conv.%
Pictet-Spengler Reaction regioselective products in most cases, giving rise to only the A-ol isomer. However, when a nitrogen functionality is present, the isomeric ratio of products is altered to give mixtures of the favored 6-ol isomer and the disfavored B-ol regioisomer. such as:
Ketone: James P. Stambuli, ORGANIC LETTERS, 2008, Vol. 10, No. 22, 5289 James P. Stambuli,J. Org. Chem. XXXX, XXX, 000
Tischenko Reaction How to start the catalic cycle? being continuing to study Anthony G. M. Barrett, Michael S. Hill, O. L. 2007, Vol. 9, No. 2, 331
Hydrophosphination Anthony G. M. Barrett, Michael S. Hill, Organometallics 2007, 26, 2953
Anthony G. M. Barrett, Michael S. Hill, Organometallics 2008, 27, 497
Aldol Reaction Ryoji Noyorib, Tetrahedron Letters 42 (2001) 4669
strontium Need to develop new ligand
Mannich S. Kobayashi, Angew. Chem. Int. Ed. 2009, 48, 5927 S. Kobayashi ,Bull. Chem. Soc. Jpn. Vol. 82, No. 9, 1083
solvent effect Conditions A: DMF, RT, 17 h, Ar=2,5-xylyl. Conditions B: Ligand 4 (11 mol%), THF, RT, 24 h, Ar=p-NO2-C6H4. The addition of ligand 4 generally increased the syn selectivity
this is the first example of a catalytic asymmetric Mannich-type reaction of a sulfonylimidate
Michael Reactions Ligand: Shuj Kobayashi, J. AM. CHEM. SOC. 2008, 130, 2430
acceptor donor ligand Shu Kobayashi, Chemistry Letters Vol.38, No.3 (2009)
Motomu Kanai, Masakatsu Shibasaki, J. AM. CHEM. SOC. 2010, 132, 8862
barium Barium has the largest ionic radius, which often form oligomer Like:
Diels–Alder-type reaction Motomu Kanai, Angew. Chem. 2009, 121, 1090
Aldol Reaction First example of an optically active alkaline meta catalyst up to 70 ee% Masakatsu Shibasaki, Tetrahedron Letters 39 (1998) 5561
Mannich reaction ligand Shu Kobayashi, Chem. Commun., 2007, 1236