'High-surface sodium' as a reducing agent for TiCl 3

Article abstract of DOI:10.1055/s-1995-3854

Sodium deposited on inorganic supports such as Al₂O₃, TiO₂ and NaCl ('high-surface sodium') is a cheap, readily prepared, nonpyrophoric reducing agent for TiCl₃. The low-valent titanium thus obtained, after only 1 h reduction time, is well suited for McMurry coupling reactions, particularly of aromatic carbonyl compounds. It exhibits a previously unrivalled template effect for the cyclization of dicarbonyl compounds to (macrocyclic) cycloalkenes and is suitable for the reduction of N-acyl-2-aminobenzophenone derivatives to 2,3-disubstituted indoles. Even a 36-membered ring could be formed without recourse to high dilution techniques.