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何玉萍 2012-12-08 Palladium(II)-Catalyzed Alkene Functionalization.

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Presentation on theme: "何玉萍 2012-12-08 Palladium(II)-Catalyzed Alkene Functionalization."— Presentation transcript:

1 何玉萍 2012-12-08 Palladium(II)-Catalyzed Alkene Functionalization

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3 Smidt, J. Angew. Chem. 1959, 71, 176; Angew. Chem., Int. Ed. 1962, 1, 80. Wacker Oxidation

4 Versatility of the Pd II -Alkyl Intermediate Arising from Alkene Nucleopalladation

5 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

6 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 :

7 Hayashi, T. J. Am. Chem. Soc. 1999, 121, 5063 Tetrasubstituted Alkenes

8 Trisubstituted Alkenes Hayashi, T. J. Org. Chem. 1999, 64, 1620.

9 Zhang, W. B. Tetrahedron Lett. 2007, 48, 4179. J. Org. Chem. 2007, 72, 9208. Tetrahedron Lett. 2007, 48, 4083. Tetrahedron. 2008, 64, 9413.

10 Stoltz, B. M. Angew. Chem., Int. Ed. 2003, 42, 2892; J. Am. Chem. Soc. 2005, 127, 17778.

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12 [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

13 Zhang, W. B. Angew. Chem., Int. Ed. 2012, 51, 9141.

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15 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.

16 Sasai, H. Tetrahedron: Asymmetry 2010, 21, 767.

17 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

18 Overman, L. E. J. Am. Chem. Soc. 2005, 127, 2866. 1.2 Addition of Carboxylic Acids to (Z)-Allylic Trichloroacetimidates

19 Mechanism (Illustrated for Catalysis by (+)-COP-OAc)

20 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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22 Plausible Mechanism of Tandem Cyclization viathe Oxy-palladation

23 Yoshida, Z. Tetrahedron Lett. 1985, 26, 4479.

24 Sasai, H. Org. Lett. 2010, 12, 3480. Cylization of  - Dicarbonyl nucleophilies

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26 Plausible Mechanism

27 Hosokawa, T. J. Org. Chem. 2009, 74, 3048. Intermolecular Alkoxyvinylation of Viny Ethers

28 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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30 Sigman, M. S. J. Am. Chem. Soc. 2009, 131, 17074. Sigman, M. S. J. Am. Chem. Soc. 2010, 132, 7870.

31 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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