Sugar ligands in organotitanium complexes

Abstract

Using ligands derived from D-glucose, dinuclear organotitanium compounds with interesting structural features were synthesized.

Monosaccharide Ligands in Organotitanium and Organozirconium Chemistry

“…CpTiCl 3 could then be reacted with one equivalent of the monosaccharide in the presence of triethylamine. With the hydroxyl function at C3 being the only remaining reactive site, we were able to obtain dichlorido-(h 5 -cyclopentadienyl)- (methyl-2-O-benzoyl-4,6-O-benzylidene-a-D-glucopyranosidato-1kO 3 )titanium (4) and the crystal structure thereof (Figure 9.3). The coordination of the ligands of 4 resembles a typical precursor compound for catalytic reactions.…”

“…Our interest in the coordination chemistry of Ti when reacted with carbohydrate ligands has led to previously reported reactions [4,5]. The reaction of methyl-4,6-Obenzylidene-b-D-glucopyranoside (b-MeBnGluH 2 ) with the organotitanium complex Cp à TiCl 3 in the presence of triethylamine gave the dinuclear titanium complex (T-4-R; T-4-R)bis[chlorido(h 5 -pentamethylcyclopentadienyl)][m-(methyl-4,6-O-benzylidene-b-D-glucopyranosidato-1kO 2 , 2kO 3 )][m-(methyl-4,6-O-benzylidene-b-D-glucopyranosiActivating Unreactive Substrates: The Role of Secondary Interactions.…”

“…Our interest in the coordination chemistry of Ti when reacted with carbohydrate ligands has led to previously reported reactions [4,5]. The reaction of methyl-4,6-Obenzylidene-b-D-glucopyranoside with the organotitanium complex (1), with two glucopyranosidato ligands (Scheme 9.1).…”

“…In particular we are investigating the 2-and 3-positions of pyranosides as coordination sites for organometallic complexes of the early transition metal Ti. The torsion angle between the oxygen functions of C2 and C3 of the pyranosidato ligand may determine whether a mononuclear chelate complex or a dinuclear compound with a bridging coordination between two Ti atoms is formed.Our interest in the coordination chemistry of Ti when reacted with carbohydrate ligands has led to previously reported reactions [4,5]. The reaction of methyl-4,6-Obenzylidene-b-D-glucopyranoside (b-MeBnGluH 2 ) with the organotitanium complex Cp à TiCl 3 in the presence of triethylamine gave the dinuclear titanium complex (T-4-R; T-4-R)bis[chlorido(h 5 -pentamethylcyclopentadienyl)][m-(methyl-4,6-O-benzylidene-b-D-glucopyranosidato-1kO 2 , 2kO 3 )][m-(methyl-4,6-O-benzylidene-b-D-glucopyranosiActivating Unreactive Substrates: The Role of Secondary Interactions.…”

Group 4 metallocenes in bioorganometallic chemistry

“…asymmetric allylation processes. Recently, Heck et al [9] have prepared a remotely related mono-Cp * Ti carbohydrate complex (1) by treatment of a selectively protected glucose derivative and determined its dimetallic ten-membered ring core structure by X-ray diffraction (Scheme 2).…”