Chiral zeolitic materials with intrinsically chiral frameworks are highly desired because they can combine both shape selectivity and enantioselectivity. In the field of zeolite, the synthesis of chiral polymorph A of zeolite Beta or chiral polymorph A-enriched zeolite Beta is one of the biggest challenges. We demonstrate here a generalized extremely concentrated fluoride route for the synthesis of chiral polymorph A-enriched zeolite Beta in the presence of five achiral organic structure-directing agents. The polymorph A-enriched Ti-Beta shows a higher enantioselectivity for the asymmetric epoxidation of alkenes than the normal Ti-Beta.

Polymorph A-enriched zeolite beta was hydrothermally synthesized from an extremely concentrated system using tetraethylammonium hydroxide (TEAOH) as an organic structure-directing agent (OSDA) in the presence of fluoride. The sample was investigated by powder X-ray diffraction (XRD), 29 Si magic angle spinning nuclear magnetic resonance (MAS NMR), 19 F MAS NMR, and high-resolution transmission electron microscopy (HRTEM). The polymorph A enrichment was confirmed by the characterization, and the percentage of polymorph A was determined to be approximately 66% by DIFFaX simulation and HRTEM analyses. A pure polymorph A stacking area was detected by HRTEM, and the chiral structure of polymorph A in the zeolite beta was investigated on the basis of the HRTEM images.