Reaction #816412

Reaction equation

product

2-Iodo-3-formylaminothiophene

ethinyl trimethylsilane

→

2-(trimethylsilylethinyl)-3-formamido-thiophene

Yield 95.3%

Solvents

DMF

triethylamine

Conditions

Workup

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   OtherAfter 6 hours the solvents were removed under vacuum
3. 3
   Otherthe residue was chromatographed on silica gel (hexane:ethyl acetate 2:1)

Procedure

The product from step A (37.8 g) was dissolved in a mixture of DMF (500 ml) and triethylamine (50 ml). CuI (1.4 g) and bis(triphenylphosphino)palladiumdichloride (5.2 g) were added under nitrogen and after 15 minutes ethinyl trimethylsilane (22 g) was added dropwise. After 6 hours the solvents were removed under vacuum and the residue was chromatographed on silica gel (hexane:ethyl acetate 2:1) to yield 2-(trimethylsilylethinyl)-3-formamido-thiophene (31.78 g) (m.p. 87-93° C.).

Source