The problem I have with the Stille coupling is that it always works. How do you like the sound of that? When Suzuki, Kumada, Negishi fail one after the other with certain troublesome substrates, Stille always comes to the rescue. Yields may vary, yields do vary, but there is always product. The problem then? Toxicity. Making Stille reagents is dangerous. Running Stille reactions is dangerous. Working up the product and taking care of Stille byproducts is dangerous. Especially at scale. Every little part of it, including that peculiar smell – toxic.
Dear geniuses out there, in academia, industry or wherever you hide, will you please come out and kick some life in the Hiyama coupling?
The day one can take a R-TMS (yes, straight TMS, no fiddling around with alkoxy-substituents) and make it as reactive as R-SnMe3 under cross-coupling conditions will be a good day. I hope I will live to see it.