Solvent-Free Solid Acid-Catalyzed Electrophilic Annelations: A New Green Approach for the Synthesis of Substituted Five-Membered N-Heterocycles
作者:Mohammed Abid、Andrew Spaeth、Béla Török
DOI:10.1002/adsc.200606200
日期:2006.10
An effective microwave-induced, solid acid-catalyzed, environmentally benign synthesis of substituted pyrroles, indoles and carbazoles under solvent-free conditions is described. The new synthetic methodology is based on the use of a considerably strong solid acid, K-10 montmorillonite. Both the cyclialkylation of amines and annelation of pyrroles and indoles have been completed within minutes and
Amino-functionalized 2,2′-bipyridines are versatile building blocks for the synthesis of sophisticated chelating ligands with the 2,2′-bipyridine core. The 4-, 5-, and 6-substituted 2-chloro- and 2-bromopyridine building blocks were prepared and coupled to symmetrically and non-symmetrically diamino-functionalized compounds by homo- and cross-coupling procedures. Further transformations were carried out to demonstrate the synthetic versatility of these compounds and the employed procedures.