I have worked with some thiophenes, and 3-bromothiophene was one of them.
Please check Heterocycles, 55(
, 1475-1486; 2001
and Synthetic Communications, 23(9), 1235-8; 1993.
To make your compound ie 3-trimethylsilylthiophene, you can start with the commercially available 3-bromothiophene.
By the way,don't you think your route has extra steps ? and to get rid of mercury is quite a task?