24.12.2012 Views

chapter 2 palladium catalysts in suzuki cross- coupling reaction

chapter 2 palladium catalysts in suzuki cross- coupling reaction

chapter 2 palladium catalysts in suzuki cross- coupling reaction

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

R 1<br />

R 1<br />

4. Sonogashira Reaction:<br />

H + R 2<br />

5. Tsuji-Trost Reaction:<br />

X<br />

+<br />

6. Negishi Reaction:<br />

ZnR<br />

X<br />

R 1 = alkyl, aryl, v<strong>in</strong>yl<br />

R 2 = aryl, benzyl, v<strong>in</strong>yl<br />

X= Br, Cl, I, OTf<br />

NuH<br />

cat. [Pd 0 L n] R 2<br />

cat. CuX, base<br />

cat. [Pd 0 L n]<br />

base<br />

X= Br, Cl, OCOR, OCO 2R, OSO 2R, P(=O)(OR) 2<br />

NuH= ß-dicarbonyls, ß-ketosulfones, enam<strong>in</strong>es, enolates<br />

2 R3<br />

+<br />

X<br />

R 1<br />

cat. [Pd 0 L n] R 1<br />

R 1 = alkyl, alkynyl, aryl, v<strong>in</strong>yl<br />

R 3 = acyl, aryl, benzyl, v<strong>in</strong>yl<br />

X= Br, I, OTf, OTs<br />

Figure 2.2. Palladium-catalyzed <strong>cross</strong>-coupl<strong>in</strong>g <strong>reaction</strong>s<br />

(Source: Nicolaou et al. 2005)<br />

Among these <strong>reaction</strong>s catalyzed by <strong>palladium</strong>, four ma<strong>in</strong> catalytic methods are<br />

used for the synthesis of biaryls which are important build<strong>in</strong>g blocks of numerous<br />

agrochemicals, pharmaceuticals, natural products, polymers, advanced materials, liquid<br />

crystals, and ligands. These are Kharasch Reaction, Negishi Reaction, Stille Reaction<br />

and Suzuki Reaction. Compared to other methods of biaryl synthesis, Suzuki <strong>cross</strong>coupl<strong>in</strong>g<br />

<strong>reaction</strong> is the most important one for <strong>in</strong>dustrial and academic area.<br />

Nu<br />

R 3<br />

7

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!