A Palladium Iodide-Catalyzed Cyclocarbonylation Approach to Thiadiazafluorenones.
The first example of an additive cyclocarbonylation process leading to 1-thia-4a,9-diazafluoren-4-ones is reported. This process is based on the reaction of readily available 2-(propynylthio)benzimidazoles with carbon monoxide carried out in EtOH at 100 °C under a 5/2 mixture of CO-CO2 at 70 atm in the presence of the PdI2/KI catalytic system. Experimental evidence suggests a mechanistic pathway involving N-palladation of the substrate followed by CO insertion, triple bond insertion, protonolysis, and isomerization.
Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria , Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy.
Lucia
L
Veltri
Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria , Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy.
Veronica
V
Paladino
Department of Chemistry and Chemical Technologies, University of Calabria , Via Pietro Bucci 14/C, 87036 Arcavacata di Rende (CS), Italy.
Pierluigi
P
Plastina
Laboratory of Industrial and Synthetic Organic Chemistry (LISOC), Department of Chemistry and Chemical Technologies, University of Calabria , Via Pietro Bucci 12/C, 87036 Arcavacata di Rende (CS), Italy.
Bartolo
B
Gabriele