Synthesis of Fused Heterocycles by a Novel 1,2-Silyl Shift – Friedel–Crafts Domino Process
29th International Society of Heterocyclic Chemistry Congress: Program 2024
Artjoms Ubaidullajevs, Rasma Kroņkalne, Krišjānis Gercāns, Anatolijs Mišņovs, Māris Turks

Herein we report a new synthetic pathway to fused heterocycles such as chromanes and 1,2,3,4-tetrahydroquinolines. The key synthetic step involves tandem 1,2-silyl shift – Friedel–Crafts cyclization (Scheme 1). First, propargyl silane 1 undergoes an electrophilic attack, which induces silyl group migration in an anti-fashion. This provides a relatively stable allylic cation 2, which can further react with the internal nucleophile. Previously, our scientific group succesfully applied this concept by affording 5-membered heterocycles 3a.1 In this work, we expand our method to the synthesis of larger heterocycles 3b, where aromatic system acts as the inner nucleophile via Brønsted acid catalysis. Additionally, we have optimized the synthesis of functionalized propargyl silanes 1 from commercially available alkynols. This synthesis includes O-silylation, retro-Brook rearrangement2a under Schlosser conditions and modified2b Mitsunobu reaction with corresponding aryl nucleophiles. In order to increase functionalization of the molecule, terminal alkyne 1 can be easily converted to haloalkyne and employed in same catalytic conditions to yield various fused heterocycles with Z-selective alkene side chain.


Atslēgas vārdi
1,2-Silyl Shift, Friedel–Crafts Cyclization, Fused Heterocycles, Propargyl Silanes, Domino Process

Ubaidullajevs, A., Kroņkalne, R., Gercāns, K., Mišņovs, A., Turks, M. Synthesis of Fused Heterocycles by a Novel 1,2-Silyl Shift – Friedel–Crafts Domino Process. No: 29th International Society of Heterocyclic Chemistry Congress: Program, Portugāle, Aveiro, 21.-26. jūlijs, 2024. Aveiro: 2024, 5.-5.lpp.

Publikācijas valoda
English (en)
RTU Zinātniskā bibliotēka.
E-pasts: uzzinas@rtu.lv; Tālr: +371 28399196