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

✍ Scribed by Marianna Carafa; Monica Distaso; Valentina Mele; Francesca Trani; Eugenio Quaranta

• Publisher: Elsevier Science
• Year: 2008
• Tongue: French
• Weight: 141 KB
• Volume: 49
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/j.tetlet.2008.03.129

✦ Synopsis

Carbonic acid diesters have been investigated as carbonylating agents in the direct reaction with pyrrole (HetNH). In the presence of superbases (DBU, P 1 -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) 2 CO) 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.