Ti-TADDOL catalysts provide good reactivity and moderate enantioselectivity in the asymmetric [2+2] cycloaddition of silyl ketenes and aldehydes. The effects of potential bidentate chelation of benzyloxy substituted aldehydes and of the steric size of the ketene silyl group were studied.
Yang, H. W., & Romo, D. (1998). Studies of the asymmetric [2+2] cycloaddition of silylketenes and aldehydes employing Ti-TADDOL catalysts. Tetrahedron Letters, 39(19), 2877–2880. https://doi.org/10.1016/S0040-4039(98)00422-5