The Synthesis of 7-Membered Heterocycles through One-pot Intramolecular Stille Coupling-Cyclization of Vinyl Tin

During my PhD thesis work, I successfully prepared a series of azepine-type of 7-membered rings taking advantage of the cis-oriented amino group of a vinyl tin precursor to demonstrate a straightforward access of bicyclic hetero-aromatic compounds (J. Org. Chem. 1993, 58, 1443).

This cis Vinyl Tin compound,  Z-3-(Tributylstannyl)-2-propen-1-amine [146829-37-0], was prepared through a lithiation-stannylation chemistry, as one aspect of the broader research in "Design and Synthetic Applications of γ-Amino Organometallic Agents".

It’s my pleasure to see that, 20 years later,  there are currently over 15 commercial vendors who sell this vinyl tin as a reagent. What makes me, a medicinal chemist, even more pleased is that the very concept of intramolecular Stille coupling-cyclization has been indeed applied in the synthesis of therapeutically useful compounds, PI3K and mTor kinases inhibitors, in a 2014 US patent US 8,765,746 B2. 

I guess, it is the whole purpose of synthetic methodogy research that you hope one day people will find what you did is unique and useful, and try it out in their own synthesis.