Indium-Based Catalytic Systems

No additional phosphines or cooper salts were required, and InCfi itself catalyzed this transformation. Additional studies are required in order to carefully evaluate the mechanism of this transformation, which undoubtedly is different from that of the palladium-mediated Sonogashira reactions. Nonetheless, the simplicity and activity of the catalytic system, as well as its generality with respect to the nature of the leaving group, renders this a promising alternative for the synthesis of internal alkynes. 

---

Broderick and co-workers developed one of such alkoxide based catalysts for LA ROP reaction by using ferrocene derivatives, 31-32 [35]. They showed that by using yttrium t-butoxide, LA ROP reaction could be proceeded with 31 but clogged with 32. Consequently, they designed a catalytic system that stopped by addition of FcBAr and resumed by addition of CoCp. Nevertheless, if the metal alkoxide changed to indium phenoxide, this effect will be reversed. 

---