Superbase promoted direct N-Carbonylation of pyrrole with carbonic acid diesters

• Published in: Tetrahedron Letters
• Main Authors: CARAFA M, DISTASO M, MELE V, TRANI F, QUARANTA, Eugenio
• Other Authors: Carafa, M, Distaso, M, Mele, V, Trani, F, Quaranta, Eugenio
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2008
• Subjects: organic carbonate; catalysi; pyrrole; carbonylation; phosgene substitution; Carbonic acid
• Online Access: http://hdl.handle.net/11586/75287; https://doi.org/10.1016/j.tetlet.2008.03.129

Carbonic acid diesters have been investigated as carbonylating agents in the direct reaction with pyrrole (HetNH). In the presence of superbases (DBU, P1-t-Bu, BTPP) as catalysts, the heteroaromatic substrate can be N-carbonylated by direct reaction with carbonic acid diesters under not-severe experimental conditions. The carbonylation reaction makes accessible pyrrole N-carbonyl derivatives (Het- NC(O)OR, (HetN)2CO) selectively through a simple straightforward way, which offers a safe eco-friendly alternative to the traditional synthetic methods based on hazardous phosgene or phosgene-derivatives.