11/29/11 - Silyl Enolate Thermodynamic Product

   Now that yesterday's reaction was the kinetic product of the silylation of an enolate I feel it is right to show the opposite where the thermodynamic product is formed.  The requirements for this reaction that differ from the previous one is that the base needed here must be a reversible one, which would cause all of the kinetic products to be reformed and converted to the most thermodynamically favorable product.  And that base here is HMDS, or hexamethyldisilazane.

11/28/11 - Silyl Enolate Kinetic Product

     In creating the kinetic product, that being the product with the lower energy transition state and the higher energy product, of a silyl enolate it is required that a bulky base is used to deprotonate the alpha position of the carbonyl.  In this case, the most popular base used is the Hunig's base, or otherwise known as N,N-Diisopropulethylamine, which quickly and irriversibly creates the enolate that in turn attacks a silyl triflate (here being TMS triflate).