BENZIL DERIVATIVES AS TRAPPING REAGENTS FOR THE MONOMERIC ALKYLINDIUM(I) COMPOUND IN-C(SIME3)(3)

The tetrahedral cluster compound tetrakis([tris(trimethylsilyl) methyl ]indium(I)) (1) reacts in boiling n-hexane with benzil derivatives (p- X-C6H4)C(O)C(O)(p-X-C6H4) (X = H, OMe, Br), to yield the 1,4-cycloaddi tion products of the monomeric alkylindium(I), In-C(SiMe3)(3), in whic h the In atoms are coordinated by a chelating enediolato ligand, to fo rm a five-membered InO2C2 heterocycle. As shown by two crystal structu re determinations (X = H, OMe), the products are dimeric in the solid state, with a four-membered In2O2 heterocycle in the molecular center and both C(SiMe3)(3) groups, as well as both enediolato substituents i n a cis arrangement.