Synthetic Reactions Using a Low-Valent Titanium Reagent Ti(OR)₄/Me₃SiCl/Mg

Abstract

In the presence of Me₃SiCl or MgCl₂, Ti(OR)₄ was reduced by Mg powder in THF to gradually generate a specific low-valent titanium species, which mediated or catalyzed several synthetic reactions such as C-O bond-cleavage of allyl and propargyl ethers and esters, intra- and intermolecular cyclotrimerization of alkynes, reduction of epoxides and oxetanes via homolytic ring-opening, McMurry coupling reaction of aryl aldehydes, imino-pinacol coupling and reductive N-S or O-S bond-cleavage of sulfonamides or sulfonyl esters.