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何玉萍 2012-12-08 Palladium(II)-Catalyzed Alkene Functionalization
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Smidt, J. Angew. Chem. 1959, 71, 176; Angew. Chem., Int. Ed. 1962, 1, 80. Wacker Oxidation
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Versatility of the Pd II -Alkyl Intermediate Arising from Alkene Nucleopalladation
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1. Enantioselective Reaction involving Oxypalladation 1.1 Phenol Cyclization 1.2 Carboxylic acid Nucleophiles 1.3 Alcohol Nucleophiles 2. Enantioselective Reaction involving Aminopalladation 3. Enantioselective Reaction involving Carbopalladation
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The first example of an enantioselective Pd-catalyzed alkene functionalization Hosokawa, T.; J. Chem.Soc., Chem. Commun. 1978, 687; J. Chem. Soc., Chem.Commun. 1979, 475. 2.1 Phenol Cyclization Electronic Effect :
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Hayashi, T. J. Am. Chem. Soc. 1999, 121, 5063 Tetrasubstituted Alkenes
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Trisubstituted Alkenes Hayashi, T. J. Org. Chem. 1999, 64, 1620.
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Zhang, W. B. Tetrahedron Lett. 2007, 48, 4179. J. Org. Chem. 2007, 72, 9208. Tetrahedron Lett. 2007, 48, 4083. Tetrahedron. 2008, 64, 9413.
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Stoltz, B. M. Angew. Chem., Int. Ed. 2003, 42, 2892; J. Am. Chem. Soc. 2005, 127, 17778.
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[a] Unless noted, reactions were carried out using 0.25 mmol of starting material, 5 mol% Pd(TFA) 2 (0.0125 mmol), 20 mol% pyridine(0.05 mmol), 0.5 mmol additive, 125 mg MS3A (500 mg/mmol substrate), and 1 atm O 2 in 1.0 mL (entries 1–5) or 2.5 mL (entries 6–7) PhCH 3 at 80 o C. All yields are based on isolated product. [b] The starting Material was used as a mixture of E and Z alkenes. [c] 10 mol% Pd(TFA) 2, 40 mol% pyridine, 2 equiv LiOAc. [d] 3:1 Z:E. [e] 10 mol% Pd(TFA) 2, 40 mol% pyridine. [f ] 2 equiv Na 2 CO 3 were added. Aerobic oxidative heteroatom/alkene cyclizations
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Zhang, W. B. Angew. Chem., Int. Ed. 2012, 51, 9141.
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Tietze, L. F. Angew. Chem., Int. Ed. 2005, 44, 257; Chem.—Eur. J. 2006, 12, 8770; Chem.—Eur. J. 2008, 14, 8956; Heterocycles 2007, 74, 473.
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Sasai, H. Tetrahedron: Asymmetry 2010, 21, 767.
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Overman, L. E.; Org. Lett. 2007, 9, 911. Adv. Synth. Catal. 2009, 351, 3186. Nonoxidation Intermolecular Addition of Phenols to (Z)-Allylic Trichloroacetimidates Addition of Phenols to (E)-Allylic Trichloroacetimidates
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Overman, L. E. J. Am. Chem. Soc. 2005, 127, 2866. 1.2 Addition of Carboxylic Acids to (Z)-Allylic Trichloroacetimidates
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Mechanism (Illustrated for Catalysis by (+)-COP-OAc)
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2.3 Alcohol Nucleophiles 2.3.1 Addition of Alcohols to Unactivated Alkene Sasai, H. J. Am. Chem. Soc. 2001, 123, 2907; Heterocycles 2004, 62, 831.
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Plausible Mechanism of Tandem Cyclization viathe Oxy-palladation
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Yoshida, Z. Tetrahedron Lett. 1985, 26, 4479.
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Sasai, H. Org. Lett. 2010, 12, 3480. Cylization of - Dicarbonyl nucleophilies
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Plausible Mechanism
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Hosokawa, T. J. Org. Chem. 2009, 74, 3048. Intermolecular Alkoxyvinylation of Viny Ethers
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2.3.2 Addition of Alcohols to ortho-Vinyl Phenols Sigman, M. S. J. Am. Chem. Soc. 2006, 128, 2794. Sigman, M. S. Org. Lett. 2006, 8, 5557.
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Sigman, M. S. J. Am. Chem. Soc. 2009, 131, 17074. Sigman, M. S. J. Am. Chem. Soc. 2010, 132, 7870.
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Summary 1.Broad functional-group compatibility air- and moisture-tolerence of Pd II catalyst for preparing of important organic building blocks as well asuseful hetero- and carbocyclic molecules. 2. Only a small number of reactions proceed with very high enantiomeric excess, and the successful examples generally have been demonstrated for only a small scope of substrates. 3. Many chiral ligands appear to have deleterious effects on catalyst activity, resulting in the need for high catalyst loadings and long reaction times and a large excess of undesirable oxidants. 4. The discovery of new classes of chiral ligands compatible with the use of molecular oxygen reactivity is in need..
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