Templated bis-functionalization

An interesting templated bis-functionalization was reported by Shinkai and co-workers who introduced two boronic acid groups regio- and diastereo-selectively into C6o by using saccharides or saccharide derivatives as imprinting templates.147-149 Thus, when D-threitol was used as the template, C2-symmetric cis-3 isomers fC-49 and fA-49,150 were obtained in a nearly. 72 28 ratio after removal of the saccharide templates (Scheme 1.6).149 Competitive complexation studies indicated that D-threitol-imprinted boronic acid (fC)-49 and L-threitol-imprinted (A)-49 preferentially rebind their original templates with up to 48% d.e.148 Exploration of other regio- and diastere-oselective double [4 + 2] cycloadditions between C6o and o-quinodimethanes... 

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