Pg. Cozzi et al., A NOVEL HOMOGENEOUS LEWIS-ACID CATALYST - TEDIBENZOTETRAMETHYLTETRAAZAANNULENE-ZIRCONIUM(IV) IN A CATIONIC FORM, Synlett, (10), 1994, pp. 857-858
The catalytic properties of edibenzotetramethyl-tetraazaannulenezircon
ium(IV), [Zr(tmtaa)(OTf)2], a prototype of a novel class of organometa
llic Lewis acids capable of promoting aldol condensations and allylati
on reactions in fair to good yields have been disclosed.