Multinuclear enantiopure titanium self-assembly complexes - synthesis, characterization and application to organic synthesis

Hexa- and nonanuclear titanium complexes were obtained by self-assembly of titanium(IV)-tertbutoxide and D-mandelic acid. Suitable single crystals of these complexes were characterized by X-ray structure analysis. When used with these complexes, aldol adducts were isolated with a high degree of regioselectivity in direct aldol additions of aromatic and aliphatic aldehydes to functionalized unsymmetrical ketones. High syn-diastereoselectivities were obtained in aldol additions of enolizable aldehydes with hydroxyacetone and methoxyacetone. Copyright (c) 2007 John Wiley & Sons, Ltd.