Pyrrole synthesis via allylic sp3 C-H activation of enamines followed by intermolecular coupling with unactivated alkynes.
A conceptually novel pyrrole synthesis is reported, efficiently merging enamines and (unactivated) alkynes under oxidative conditions. In an intermolecular Rh catalyzed process, the challenging allylic sp(3) C-H activation of the enamine substrates is followed by the cyclization with the alkyne (R(3) = CO(2)R). Alternatively, in some cases (R(3) = CN), the enamine can be utilized for a vinylic sp(2) C-H activation. A total of 17 examples with yields above 60% is presented, together with the results of an initial mechanistic investigation.
Rakshit
Souvik
S
NRW Graduate School of Chemistry, Organisch-Chemisches Institut, Westfälische Wilhelms-Universität Münster, Corrensstrasse 40, 48149 Münster, Germany.
Patureau
Frederic W
FW
Glorius
Frank
F
D000480:Alkynes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry
D000480:Alkynes; D000588:Amines; D011758:Pyrroles