Chiral Titanium

DAVICAT^Ž Chiral TitaniumMolecular Sieves for Asymmetry

Dramatic effects of molecular sieve hydration on the sterochemical outcome of various organic reactions have been observed. As shown in the diagram below involving an asymmetric Diels-Adler cycloaddition (Ref. 2), these reactions include also asymmetric sulfoxidations (Ref. 3), ene reactions (Ref. 4), and cyclizations (Ref. 1). Molecular sieves produced by Grace Davison have been shown to be extraordinarily effective in these reactions (e.g. Ref. 5).

Grace Davison, a core business unit of W.R. Grace & Co. and a global leader in the molecular sieve industry, is now offering industrial scale supplies of 4A molecular sieves of specified moisture content. Free samples of small scale kits containing separate vials of 4A molecular sieves ranging from 6-18% moisture content are available upon request.

References:

Tottie L.; Baeckstrom P.; Moberg C.; Tegenfeldt, J.; Heumann, A. J. Org. Chem., 1992, 57, 6579
Posner, G.H.; Dai, H.; Bull, D.S.; Lee, J. K.; Eydoux, F.; Ishihara, Y.; Welsh, W.; Pryor, N.; Petr, S. Jr., J. Org. Chem. , 1996, 61, 671
Brunel, J.-M.; Kagan, H.B.; Bull. Soc. Chim. France, 1996, 133, 1109
Terada M.; Matsumota, Y.; Nakamura, Y.; Mikami, K., Chem. Commun., 1997, 281.
Posner, G.H.; Bull, D.S. Tetrahedron Lett. 1996, 35, 6279.