Cyclopentadiene-Phosphine/Palladium-Catalyzed Synthesis of Indolizines from Pyrrole and 1,4-Dibromo-1,3-butadienes

The
cyclopentadiene–phosphine ligand (L1) and
palladium were found to be an efficient catalyst system to activate
the α-C­(sp2)–H bond of pyrrole and indole
derivatives. Various alkenyl or aryl dibromides could be used to react
with pyrrole and indole derivatives to afford multisubstituted indolizines
in high yields.

研究表明，环戊二烯-膦配体（cyclopentadiene–phosphine ligand）L1与钯可构成高效催化体系，可活化吡咯（pyrrole）及吲哚（indole）衍生物的α-C(sp²)–H键。多种烯基或芳基二溴化物（alkenyl or aryl dibromides）可与该类衍生物发生反应，以较高收率得到多取代中氮茚（multisubstituted indolizines）。