TFAA/H<sub>3</sub>PO<sub>4</sub>mediated unprecedented N-acylation of carbazoles leading to small molecules possessing anti-proliferative activities against cancer cells
作者:Sunder Kumar Kolli、Bagineni Prasad、P. Vijaya Babu、Mohd Ashraf Ashfaq、Nasreen Z. Ehtesham、R. Ramesh Raju、Manojit Pal
DOI:10.1039/c4ob00686k
日期:——
For the first time TFAA/H3PO4 has facilitated the direct and metal-free N-acylation of carbazoles leading to a number of N-acylated derivatives. Several of these compounds were found to be promising when tested for their anti-proliferative properties against oral cancer cell lines.
Abstract N-Acyl carbazoles can be efficiently produced through a single-step process using amides and cyclic diaryliodonium triflates. This convenient reaction is facilitated by copper iodide in p-xylene, using the commonly found activating ligand diglyme. We have tested this method with a wide range of amides and iodonium triflates, proving its versatility with numerous substrates. Beyond carbazoles
9-benzoylcarbazoles with internal alkynes proceeds efficiently through ortho C–H and C–N bond cleavages. This reaction provides direct access to variously substituted indanone derivatives. The carbazolyl leavinggroup can be readily recovered and reused for preparing the starting materials. Keywords: annulation; rhodium catalyst; C–H bond cleavage
N-benzoylated carbazole derivatives were investigated. It was found that the bulky t-butyl and iodo groups restricted rotation about the N–C7′ and C7′–C1′ bonds to separate four stereoisomers, in which rotation about the C7′–C1′ bond was in perfect concert with rotation about the N–C7′ bond. The relation of the rotation of the N–C7′ and C7′–C1′ axes was investigated by comparing the stereochemistry of