Scope of TMS dance reactions

TMS-hetarylalkyne intermediates as depicted below turned out to undergo TMS migration upon initial aromatic metalation. Migration parameters as well as their selective preventions have been discussed in comparison with HD methodology.
The scope of this method is not limited to the wide range of derivatives accessible via the silyl migration step, but additionally products with a prevention pattern can be obtained selectively by adding appropriate electrophiles before warming up to ambient temperatur thus triggering the rearrangement. By these means a clean control of acetylenyl versus heteroaryl selectivity is enabled.