Title: Facile Synthesis of NH-Free 5-(Hetero)Aryl-Pyrrole-2-Carboxylates by Catalytic C–H Borylation and Suzuki Coupling.
Authors: Kanwal, Saba; Ann, Noor-ul-; Fatima, Saman; Emwas, Abdul-Hamid; Alazmi, Meshari; Gao, Xin; Ibrar, Maha; Zaib Saleem, Rahman Shah; Chotana, Ghayoor Abbas; Pérez Sestelo, José; Sarandeses, Luis A.
Abstract: A convenient two-step preparation of NH-free 5-aryl-pyrrole-2-carboxylates is described. The synthetic route consists of catalytic borylation of commercially available pyrrole-2-carboxylate ester followed by Suzuki coupling without going through pyrrole N–H protection and deprotection steps. The resulting 5-aryl substituted pyrrole-2-carboxylates were synthesized in good- to excellent yields. This synthetic route can tolerate a variety of functional groups including those with acidic protons on the aryl bromide coupling partner. This methodology is also applicable for cross-coupling with heteroaryl bromides to yield pyrrole-thiophene, pyrrole-pyridine, and 2,3'-bi-pyrrole based bi-heteroaryls.
Subjects: SUZUKI reaction; BORYLATION; FUNCTIONAL groups; ARYL bromides; PROTONS; THIOPHENES
Publication: Molecules, 2020, Vol 25, Issue 9, p2106
ISSN: 1420-3049
Publication type: Academic Journal
DOI: 10.3390/molecules25092106

Facile Synthesis of NH-Free 5-(Hetero)Aryl-Pyrrole-2-Carboxylates by Catalytic C–H Borylation and Suzuki Coupling.

Kanwal, Saba; Ann, Noor-ul-; Fatima, Saman; Emwas, Abdul-Hamid; Alazmi, Meshari; Gao, Xin; Ibrar, Maha; Zaib Saleem, Rahman Shah; Chotana, Ghayoor Abbas; Pérez Sestelo, José; Sarandeses, Luis A.