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Suzuki Coupling in LC Synthesis Yu Ding Nov 17 2003.

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Presentation on theme: "Suzuki Coupling in LC Synthesis Yu Ding Nov 17 2003."— Presentation transcript:

1 Suzuki Coupling in LC Synthesis Yu Ding Nov

2 Different Types of Liquid Crystal

3 What is Suzuki Coupling

4 Why Choose Organoboron Compounds Advantage of Organoboronic acids: Tolerate wide range of function groups Commercially available Thermal stable, inert to oxygen and water Can be crystallized from water or alcohols Reaction can be carried out under aqueous conditions Nontoxic by-product

5 General Mechanism

6 Preparation of Organoboron Compounds

7 Reaction Conditions Pd(PPh 3 ) 4 or PdCl 2 ( PPh 3 ) 2 with aq. Na 2 CO 3 in DME Palladium catalysts with or without a phosphine ligand Some other bases: Et 3 N, NaHCO 3, CsCO 3,TlCO 3, K 3 PO 4, have been used Homogenous or heterogeneous conditions e.g. K 2 CO 3 suspended in toluene

8 Cross-coupling of Aryl Bromide and Aryl Iodide

9 Bulky Effect in the Cross-coupling

10 By-products in the Cross-coupling

11 Direct Ortho-Metallation-Boronation

12 Cross-coupling with Aryl Triflates and Aryl Chloride

13 High Dielectric Biaxiality Ferroelectric Liquid Crystal Mixture

14 Synthetic Approach to Compounds III

15 Transition Temperatures for Compounds III

16 Extended Triphenylenes J.Mater.Chem,2000,10,

17 Observation Transition Temperature Compounds Observed Transition temperature ( 0 C) R=C 6 H 13 Cr 111 Col 126 I R=C 8 H 17 Cr 85 Col 104 I R=C 10 H 21 Cr 74 Col 103 I R=C 12 H 25 Cr 47 Col 101 I

18 Conclusion Suzuki coupling reaction represents one of most straightforward methods of carbon-carbon bond formation The reaction proceeds under mild conditions  unaffected by the presence of water,air  broad range of functionality  yield nontoxic by-products It has been widely applied in academic and industrial lab.


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