Chiral porous TADDOL-embedded organic polymers for asymmetric diethylzinc addition to aldehydes

Abstract

Two chiral porous organic polymers (CPOPs) were synthesized by linking a TADDOL-embedded building block with arylethynylenes units. The CPOPs are highly stable to thermal treatment, moisture, acidity, and basicity. The dihydroxy groups of TADDOL inside the pores promise the CPOPs as good asymmetric catalysts after postsynthesis modification with a secondary metal center. After being treated with Ti(OiPr)4, the CPOPs could be used as highly effective and reusable heterogeneous catalyst for asymmetric diethylzinc addition to aldehydes with up to 99% conversion and 95% ee. This work promises the potential of generating chiral solid catalysts with unique and practically useful enantioselective functions via a modular approach. © 2013 The Chemical Society of Japan.