Suzuki methodology

Qudguiner made great use of Suzuki methodology to prepare heterobiaryls for use in carboline synthesis [163]. This chemistry is discussed in Chapter 4. As explored in more detail in Section... 

The same Suzuki methodology was used to synthesize a similar copolymer 446 [548], The polymer showed a solvent-dependent green-yellow emission (from 545 nm in THF to 565 nm in chloroform) as often observed for polar chromophores. The PL QE also varied with the solvent (from 11% in THF to 21% in decalin) but, in contrast to copolymer 445, no strong decrease in emission efficiency was observed in the solid state (4>p1 n= 13%) that could be attributed to the effects of substituents at the thiophene ring. LEDs based on 446 showed, for an ITO/PEDOT/446/Ca/Al architecture, a turn-on voltage of ca. 10 V with a maximum brightness of 340cd/m2 at 22 V and appreciable el = 0.14%. 

A Suzuki coupling reaction carried out under aqueous conditions features in a four-step synthesis of 3,4-fused coumarins from tetralones and chroman-4-one <02TL1213>. 4-Tosylcoumarin is a precursor of 4-arylcoumarins using Suzuki methodology <02TL4395>. 

Queguiner made great use of Suzuki methodology to prepare heterobiaryls for use in carboline synthesis [169]. This chemistry is discussed in Chapter 4. As explored in more detail in Section 3.5, Grigg developed several Pd-catalyzed tandem cyclization-anion capture processes, and these include organoboron anion transfer agents [109, 170, 171], Two examples of this methodology are shown. 

Another synthesis of dragmacidin D is described using the Suzuki methodology [5,7]. 

A -unsubstituted 4,5-dichloropyridazin-3(277)-one (109) fails to undergo Suzuki crosscoupling reactions. In order to synthesize N-2, unsubstituted 4,5-diarylpyridazin-3(2//)-ones (112) by Suzuki reaction, the temporary protection of the lactam moiety of 109 is essential. To achieve this a simple and efficient retro-ene-assisted Suzuki methodology has been developed by Ravina and co-workers which is based on 4,5-dichloro-2-(hydroxymethyl)pyridazin-3(277)-one (110) [61]. This pyridazin-3(2//)-one is easily available from 109 via reaction with formaldehyde. Interestingly, 110 reacts smoothly with arylboronic acids to afford directly the deprotected 4,5-diarylated pyridazin-3(2//)-ones (112) in high yields. The mechanism probably involves the formation of 4,5-diarylated-2-(hydroxymethyl)pyridazin-3(277)-ones (111), which subsequently lose formaldehyde by a retro-ene reaction induced by base or heat [62]. 

The same type of coupling, catalyzed by palladium(O), can be carried out using alkenylboronates (generated by hydroboration of acetylenes) and -P-bromoacrylamides [49]. This Suzuki methodology has been used for the synthesis of pellitorine (1), trichonine (13), piperlonguminine (23), piperine (25), dehydropipernonaline (29) and 1-piperettylpyrrolidine (34) [34] (Scheme 6). 

Suzuki methodology, with a 3-halotriazolopyridine and an aryl or heteroaryl boronic acid, sodium carbonate and tetrakistriphenylphosphine as catalyst, the synthesis of 3-aryl derivatives 6b-g, i, j, ha ve been described (Figure 2). In these reactions a secondary compound was also formed, the 33 -bitriazolopyridine 37 (Figure 10), as a consequence of a homocoupling Ullman reaction. From 7-bromo-3-methyl-triazolopyridine, the synthesis of some 7-aryl derivatives 7a-g in very good yields (60-90%) was also reported (Figure 2) (06TL8101). 

Anderson, J.C. Namli, H. (1995) Ambient-temperature unsymmetrical bialyl synthesis using Suzuki methodology, Synlett, 765-6. 

Other syntheses using the Suzuki methodology include the preparation of carbon-ll-labeled palmitic acid with carbon-11 at the terminal position and a diaryl alkyne, glutamate-receptor agent, Figure 5.1. ... 

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