26205-83-4Relevant academic research and scientific papers
Synthesis of bench-stable diarylmethylium tetrafluoroborates
Barbero, Margherita,Buscaino, Roberto,Cadamuro, Silvano,Dughera, Stefano,Gualandi, Andrea,Marabello, Domenica,Cozzi, Pier Giorgio
, p. 4791 - 4796 (2015)
A representative number of bench-stable nonsymmetric diarylcarbenium tetrafluoroborates have been isolated via the direct coupling of aryl (or heteroaryl) aldehydes and N-heteroarenes and fully characterized. They have proven to be highly stable in the pr
Cobalt-catalysed reductive C-H alkylation of indoles using carboxylic acids and molecular hydrogen
Cabrero-Antonino, Jose R.,Adam, Rosa,Junge, Kathrin,Beller, Matthias
, p. 6439 - 6450 (2017/08/29)
The direct CH-alkylation of indoles using carboxylic acids is presented for the first time. The catalytic system based on the combination of Co(acac)3 and 1,1,1-tris(diphenylphosphinomethyl)-ethane (Triphos, L1), in the presence of Al(OTf)3 as co-catalyst, is able to perform the reductive alkylation of 2-methyl-1H-indole with a wide range of carboxylic acids. The utility of the protocol was further demonstrated through the C3 alkylation of several substituted indole derivatives using acetic, phenylacetic or diphenylacetic acids. In addition, a careful selection of the reaction conditions allowed to perform the selective C3 alkenylation of some indole derivatives. Moreover, the alkenylation of C2 position of 3-methyl-1H-indole was also possible. Control experiments indicate that the aldehyde, in situ formed from the carboxylic acid hydrogenation, plays a central role in the overall process. This new protocol enables the direct functionalization of indoles with readily available and stable carboxylic acids using a non-precious metal based catalyst and hydrogen as reductant.
Preparation and characterization of aryl or heteroaryl(3-indolyl)methylium o-benzenedisulfonimides
Barbero, Margherita,Cadamuro, Silvano,Cauda, Fabrizio,Dughera, Stefano,Gervasio, Giuliana,Venturello, Paolo
, p. 4278 - 4287 (2012/07/17)
An initial study has been accomplished into the synthetic feasibility of the preparation of diarylcarbenium salt via the direct coupling of aryl (or heteroaryl) aldehydes and arenes (or heteroaryl analogues) in the presence of a strong organic Bronsted acid. A number of stabilized aryl or heteroaryl(3-indolyl)carbenium ions, never previously prepared in the solid state, have been isolated in excellent yields as highly stable o-benzenedisulfonimide salts and have been fully characterized. Their purity has been proven by spectroscopic methods and chemical reduction with NaBH 4. An X-ray crystal structure analysis has been performed on one of the products: an azafulvenium species was shown to be the exclusive structure in the solid state.
