The activation mode of a rotaxane-based organocatalyst with both secondary amine and squaramide catalytic units can be switched with acid or base, affording different products from a mixture of three building blocks.

Acylation of lanatoside C in the presence of organocatalyst 5 gave the C(4'''')-O-acylate in up to 90% regioselectivity (catalyst-controlled regioselectivity). Various functionalized acyl groups can be introduced at the C(4'''')-OH by a mixed anhydride method in the presence of 5 or the related organocatalyst. On the other hand, DMAP-catalyzed acylation of lanatoside C gave the C(3'''')-O-acylate in up to 97% regioselectivity (substrate-controlled regioselectivity). Thus, diverse regioselective introduction of acyl groups among eight free hydroxy groups of lanatoside C was achieved.

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Organocatalytic regioselective acylation of mono- and disaccaharides with various functionalized acid anhydrides has been developed. Acylation of octyl beta-D-glucopyranoside with acid anhydrides derived from alpha-amino acids, cinnamic acid, and gallic acid took place at C(4)-OH with 67-94% regioselectivity in the presence of catalyst 1. Regioselective acylation of disaccharides with functionalized acid anhydrides was also achieved with 78-94% selectivity. Especially, a disaccharide with seven free hydroxy groups (X = OH, R' = H) underwent acylation at C(4)-OH with 78% regioselectivity in the presence of 1. Thus, functional group tolerance in the regioselective acylation catalyzed by 1 was found to be high.