Thiazole 4-lithio-2-trimethylsilyl

Lithiothiazoles are the starting material for the preparation of other metallated thiazoles. Thus, transmetallation of 2-lithiothiazole with trimethylsilyl chloride can be carried out in one-pot and multigram scale to give the stable and synthetically important 2-trimethylsilylthiazole 774. In the same way, 2- and 4-trimethylstannylthiazoles 775 and 776 can be obtained from the corresponding lithio derivatives and trimethyltin chloride. 4-Methyl-2-trimethylstannylox-azole reacts with a variety of aryl and heteroaryl halides and tetrakis(triphenylphosphine)palladium to give the 2-substituted products in high yield. 

Related Reagents. Benzothiazole Carbon Monoxide A, A -Diethylaminoacetonitrile iVJV-Dimethyldithiocarbamo-ylacetonitrile 2-Lithio-l,3-dithiane Methylthiomethyl p-Tolyl Sulfone 2- Trimethylsilyl)thiazole. 

Ausgehend von entsprechenden Brom-l,3-thiazolen lassen sich iiber Lithio-l,3-thiazole auch Trimethylstannyl- Oder Trimethylsilyl-Gruppen in 2- oder 4-Position des 1,3-Thiazol-Rings einfiihren z.B. ... 

Die Umsetzung von 6-Chlor-4-lithio-2-phenyl- mit Chlor-trimethyl-silan ergibt 65% 6-Chlor-2-phenyl-4-trimethylsilyl-(pyrido[3,2-d]-l,3-thiazoi) (Schmp. 155-156")400 ... 

Related Reagents. 7V,7V Diethylaminoacetonitrile Dimethyldithiocarbamoylacetonitrile (4a/ )-(4aa, 7Q, 8a )-Hexa-hydro-4,4,7-trimethyl-4i l,3-benzoxathiin 2-Lithio-l,3-dithi-ane Nitromethane 1,1,3,3-Tetramethylbutyl Isocyanide p-Tolylsulfonylmethyl Isocyanide 2-(Trimethylsilyl)thiazole. 

The regioselective C-5 lithiation of 2-TST (1) followed by transmetalation with zinc chloride and palladium(0)-catalyzed Negishi cross-coupling was employed to prepare 5-aryl- and 5-heteroaryl-substituted thiazoles (20) in a one-pot procedure (eq 29). The lithiation and transmetalation were performed in diethyl ether because of the instability of 5-lithio-2-trimethyl-silylthiazole in THF at — 78 °C. The 2-trimethylsilyl group of the cross-coupled products was cleaved quantitatively under acidic conditions. 

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