On the Origin of Enantioselectivity in Chiral Zeolite Asymmetric Catalyst GTM-3: Host-Guest Transfer of Chirality.

Knowledge of how extra-large-pore chiral zeolite asymmetric catalysts based on the -ITV framework imprint their chirality during a catalytic reaction is crucial in order to spread the scope for the catalytic enantioselective production of chiral compounds of interest. In this work, we have carried out a combined experimental and computational study on the catalytic activity of antipode GTM-3 catalysts during the ring-opening of -stilbene oxide with 1-butanol. Identification of the enantiomers of all the chiral species unraveled a surprising catalytic behavior: these chiral catalysts promote the transformation of one enantiomer of -stilbene oxide in the corresponding product (with inversion of configuration of the attacked C) via an S2 mechanism, and at the same time, the transformation of the other enantiomer of -stilbene oxide via an S1-like mechanism into the (with retention of configuration) and secondary products (diphenylacetaldehyde via rearrangement and derived products).