Asymmetric Photochemistry Liu-Zhu Gong Group Meeting September 12, 2009 Wei-Jun Liu 1.Fundemental Reaction 2.Solid-Phase 3.Solution-Phase Covalently-bound.

Slides:

Advertisements

Similar presentations

Asymmetric Synthesis Introduction.

Advertisements

Prepared by : Malak Eshtayah

Selectivity in an Encapsulated Cycloaddition Reaction Jian Chen and Julius Rebek,Jr. Org. Lett. 2002, 4, Tobe laboratory Shintaro Itano.

Iron-catalyzed Cross Coupling reactions: From Rust to a Rising Star

Rhodium Catalyzed Direct C-H Functionalization 陈殿峰

ASYMMETRIC EPOXIDATION OF OLEFINS BY SHI’S CATALYST AND

Classifying Organic Compounds

Lecture 37 Organometallic reactions and catalysis 1) Catalytic olefin hydrogenation A thermodynamically favorable reaction may be slow at modest temperatures.

Asymmetric Suzuki–Miyaura Coupling in Water with a Chiral Palladium Catalyst Supported on an Amphiphilic Resin Yasuhiro Uozumi Angew. Chem. Int. Ed. 2009,

Chp 2 Molecules and Cells in Animal Physiology Read Chp 2 of the book Use the notes for Human Physiology We will see metabolism and the enzymes in more.

Copyright © 2005 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 8.

The Nature of Organic Reactions: Alkenes and Alkynes

Chemical Change Chapter 2 Dr. Suzan A. Khayyat1. Chemical reactions Photochemical Reaction Photooxidation Reaction Photoaddition Reaction Photohydrogenation.

Year 3 CH3E4 notes: Asymmetric Catalysis, Prof Martin Wills

Alkylation by Asymmetric Phase- Transfer Catalysis 张文全.

Lecture 14 APPLICATIONS IN ORGANIC SYNTHESIS Copyright ©The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

The application of alkaline metal(Ca, Sr, Ba) complex as catalyst in organic chemistry 张文全 1.

The Concept of Active Centres in Catalysis 1 st October, 2011.

Introduction Asymmetric reduction of C=N bonds represents a powerful method for the asymmetric formation of chiral amines. 1 Whilst many methods exist.

Palladium Catalyzed Annulation Bei Zhao

Transition-Metal-Catalyzed Enantioselective Insertion of carbenes or carbenoids into the Heteroatom-Hydrogen Bond Reactions Xiaolei Lian

1 Single electron transfer reaction involving 1,3-dicarbonyl compounds and its synthetic applications Reporter: Jie Yu Oct. 31, 2009.

Introduction to catalysis Textbook H: Chapter 14 Textbook A: Part IV – Introduction.

By: Debbie Schwagerman January 31, Atomic Bonds and Molecular Interactions Each atom has a defined number and geometry of covalent bonds. Each atom.

Structure of chemical compounds Bonds and isomery Richard Vytášek 2008 Presentation is only for internal purposes of 2nd Medical faculty.

Wangqing Kong Zhu’s group meeting 13 th, Aug, 2015 Intramolecular Asymmetric Heck Reaction and Application in Natural Products Synthesis.

Carbon-Carbon Bond Forming Reactions I. Substitution Reaction II. Addition Reaction.

CARBON CARBON EVERYWHERE!! Macromolecules. Importance of carbon Single Double bonds with Oxygen Single Double bonds with Nitrogen Single Double Triple.

Bergman Cyclization of Sterically Hindered Substrates and Observation of Phenyl-Shifted Products M1 Colloquium in Division Frontier Materials Science in.

1 CATALYTIC ASYMMETRIC NOZAKI- HIYAMA-KISHI REACTION: ROLE OF ORGANOCHROMIUM COMPOUNDS AND NOVEL SALEN LIGANDS A RKAJYOTI C HAKRABARTY Prof. Uday Maitra’s.

1 Year 3 CH3E4 notes: Asymmetric Catalysis, Prof Martin Wills Reorganised to highlight key areas to learn and understand. You are aware of the importance.

High-Oxidation-State Palladium Catalysis 报告人：刘槟 2010 年 10 月 23 日.

1 Year 3 CH3E4 notes: Asymmetric Catalysis, Prof Martin Wills You are aware of the importance of chirality. This course will focus on asymmetric.

Song jin July 10, 2010 Gong Group Meeting.

Peptidomimetics and Mimicry of  -Strand / Sheets and  -Sheet Sandwiches Jian Liu Merck & Co., Inc. Rahway, NJ

Why Addition Reactions Proceed: Thermodynamic Feasibility 12-1 Because the C-C  bond is relatively weak, alkene chemistry is dominated by its reactions.

Ye Zhu 09/02/10 Burgess’s Group Meeting Chiral Ligands On A Spiro Scaffold for Transition-Metal- Catalyzed Asymmetric Reactions Work by Prof. Zhou Qi-Lin.

Literature Meeting - Charette Group – Marc K. Janes – December 6 th 2004 ACTIVATIONS BY HYDROGEN BONDING – SUCCESS STORIES Born Rajkot, India, University.

Organic Pedagogical Electronic Network Attachment of Molecular Catalysts on Solid Supports - Rh Complex on a Silica Support Jones Group, Georgia Tech Davies.

Vanadium-Catalyzed Selenide Oxidation with in situ [2,3] Sigmatropic Rearrangement: Scope and Asymmetric Applications Campbell Bourland February 6, 2002.

Supervisor: Yong Huang Reporter: Qian Wang Date: Magical Chiral Spirobiindane Skeletons.

Asymmetric BINOL-Phosphate Derived Brønsted Acids: Development and Catalytic Mechanism Reporter: Song Feifei Supervisor: Prof. Yong Huang

Catalytic Heterocycle Synthesis Group 万伯顺杂环合成中的环加成与环化反应.

Redox Relay Heck Reaction

金属催化的氧化反应 CYP 450TauD Acc. Chem. Res. 2007, 40, 522–531.

Light and Palladium Induced Carbonylation Reactions of Alkyl Iodides Mechanism and Development Pusheng Wang Gong Group Meeting April 12 th 2014.

Reporter: Yang Chao Supervisor: Prof. Yong Huang The Transformation of α ‑ Diazocarbonyl Compounds.

CHEMISTRY 4000 Topic #6: Formation of Cyclic Structures Fall 2012 Dr. Susan Findlay.

Chemical Bonding Why do atoms form bonds?. Atoms form bonds to become more…

Reaction Rates. RATES OF REACTION ARE INFLUENCED BY NATURE OF REACTANTS.

9.7 Catalytic Hydrogenation The addition of H 2 across a C=C double bond If a chirality center is formed, syn addition is observed Draw the stereoisomers.

24-1 Diels-Alder Reaction  Diels-Alder reaction:  Diels-Alder reaction: A cycloaddition reaction of a conjugated diene and certain types of double and.

1 Chapter 7 Ring closure (and ring opening) 7.1Intramolecular cyclization by electrophile- nucleophile 7.2Cycloadditon 7.3Electrocyclic ring closure 7.4Ring.

Enantioselective Reactions Catalyzed by Iron Complexes Pablo Pérez.

Halogen-Bonding Catalysis George Neuhaus Prof. Orion B. Berryman’s Lab April 11, 2014 UMCUR 1.

Robert Raja: Research Themes 2011/2  Cascade Reactions & Flow Chemistry  Vitamins  Agrochemicals  Fragrances and flavours  Food-additives Porous Molecular.

Structure of chemical compounds

Dr. Christopher Cioffi Monday 3/20/2017 9:00AM – 9:50AM

Matthew Cipolla Honors Undergraduate Research Conference

Visible light photoredox-controlled reactions of N-radicals

Concept 8.4: Enzymes speed up metabolic reactions by lowering energy barriers A catalyst is a chemical agent that speeds up a reaction without being consumed.

3 Cycloaddition and Cycloreversion Reactions.

Asymmetric Synthesis Introduction.

Enantioselective Rh-catalyzed Aldehyde C-H Activation

Enzymes Biological catalyst – it speeds up reactions without being permanently changed.

Enzymes and Feedback Inhibition

ORGANIC PHOTOCHEMISTRY Pharmaceutical Chemistry Department

Organic Reactions Enabled by Catalytically Active Metal–Metal Bonds

1. Palladium Catalyzed Organic Transformations

Presentation transcript:

Asymmetric Photochemistry Liu-Zhu Gong Group Meeting September 12, 2009 Wei-Jun Liu 1.Fundemental Reaction 2.Solid-Phase 3.Solution-Phase Covalently-bound chiral auxilliaried Chiral complexing agents Chiral sensitizer Review: Rau, H. Chem. Review. 1983, 83, Inoue, Y. Chem. Review. 1992, 92, Konig, B. Chem. Review. 2006, 106, Fagnoni, M. Chem. Review. 2007, 107, Hoffmann, N. Chem. Review. 2008, 108,

1.Fundmental Reactions 1.1 [2+2] photocycloaddition Synlett 2002, 1305 J. Am. Chem. Soc. 2009, 131, ASAP.

Paternò-Büchi Reaction (between a ketone and alkene) J. Org. Chem. 2003, 68, J. Org. Chem. 2004, 69, 33. Ang. Chem., Int. Ed. 2003, 42, 1642

1.2 Photochemical Rearrangments (di-ПЛ Synthesis 2001, 1175

The Herteroatom Variant Photochemical Rearrangments Ang. Chem., Int. Ed. 2002, 41, 4090

1.3 Norrish-Yang Reaction Synthesis 2001, 1253

1.4 Intermolecular Addition onto Double or Triple C-C Bonds J. Org. Chem. 2001, 66, 7320.

1.5 Photo-oxygenation

Why Study Asymmetric Photochemistry? Prebiotic photochemistry ---- enantiomeric excess of biomolecules may have been generated by circularly polarized light (CPL) Environmentally benign processes ---- light is ubiquitous, generates no waste. Different mode of reactivity ---- access to novel, strained compounds which are thermally inaccessible or diffcult to synthesize and low reaction temperature Short excited lifetime low activation energy for reactions in excited states Why few Examples in Enantioselective Photochemical Transformations A few energy difference of a few kilocalories per mole is sufficient to give >99% stereodifferentiation. Inoue, Y. Chem. Review. 1992, 92,

2. Enantioselective Solid-Phase Photochemistry 2.1 Host-Gest Cocrystals Toda, Chem. Comm. 1995, 621

100% ee Toda, Tanaka ACIE, 1999, 38, % ee Tanaka OL, 2002, 4, 3255

2.2 Ionic Chiral Auxiliary Scheffer ACR, 1996, 29, 203

2.3 Chiral Modified Supercages of Zeolites Ramamurthy ACR, 2003, 36, 509

3. Enantioselective Solution-Phase Photochemistry 3.1 Covalently-bound chiral auxillaries Meyer, JACS, 1986, 108, 306

Carreira, JACS, 1994, 116, 6622 JACS, 1997, 119, 2597

3.2 Chiral Complexing Agents (Templated Photochemsitry) Noncovalent Asseemblies EJOC, 2002, 2298

JOC, 1995, 60, 7984 Glycol-Metal Cation

Diaminotriazine-barbiturate ( 二氨基三唑－巴比妥酸盐）

CR, 2006, 106,

3.2.2 Complementary DNA Strands as Templates CR, 2006, 106,

3.2.3 Templates with a Covalently Bound Chromophore and Recognition Site The reaction did not proceed in the absence of the template

As an artificial functional model of a photolyase CR, 2006, 106,

3.2.4 Photochemical reaction in a molecular flask The molecular flask is significantly larger than the guest and can therefore protect Substrates from the surrounding environment and thus controls the course of a Photochemical reaction. The syn isomers were the major. The syn isomers changed to the minor. Favorite temperate scaffolds Good availability Various sizes Inherent chirality CR, 2006, 106, Cyclodextrin

Self-Assembled Molecular Cage

3.2.5 Templates Containing a Shield Mori and Nakamura, TL, 1996, 37,

Bach, T. JACS, 1999, 121,

Bach, T. ACIE, 2000, 39,

Bach, T. JACS, 2000, 122,

Bach, T. ACIE, 2003, 42,

Bach, T. OL, 2001, 3, Bach, T. CC, 2001, 607 Bach, T. CEJ, 2002, 8, 2464

Catalytic Enantioselective Photochemical Reaction Krische, J. JOC, 2003, 68, 15-21

Bach, T. Nature, 2005, 436,

Bach, T. ACIE, 2009, 48, 1-4

Polymer-Bound Chiral Temple Bach, T. ACIE, 2008, 47,

3.3 Chiral Sensitizer

Inoue JCS CC, 1993, 718 Schuster, JACS, 1990, 112, 9635 Photosensitized ant-Markovnikov methanol additiong to 1,1-diphenylpropene [4+2] cycloaddition between electron-rich diene and electron-rich dienophile

Sens* 2b : up to 70% ee Switching the product chiralty by solvent lower temperature higher ee The higheat ee ever reported for an enantiodifferentiating photosensitization. Inoue, JACS, 2000, 122,

Garcia, JOC, 2002, 67,

3.3 Activation of Substates by Chiral Catalysts (Organocatalysis) Cordova, JACS, 2004, 126, 8914 ACIE, 2004, 43, 6532

MacMillan Science, 2008, 322, 77 JACS, 2009, 131, 10875

4 Photecatalysts A: Via electron transfer

B: Via H abstraction

5. Conclusion Solid-Phase asymmetric photochemistry can work very well, but has limited. Solution-phase photochemistry is more attractive for the catalytic enantioselective photochemistry. More excellent catalysts as Bach’ catalysts and assymme- tric inducing model will be developed. Asymmetric photochemistry using chiral sensitizers is usually poorly selective.