as a service to our authors and readers , this journal provides supporting information supplied by the authors . such materials are peer reviewed and may be reorganized for online delivery , but are not copyedited or typeset . technical support issues arising from supporting information ( other than missing files ) should be addressed to the authors .
abstractthe acylation of alcohols catalyzed by n , ndimethylamino pyridine ( dmap ) is , despite its widespread use , sometimes confronted with substratespecific problems : for example , target compounds with multiple hydroxy groups may show insufficient selectivity for one hydroxyl , and the resulting product mixtures are hardly separable . here 
 we describe a concept that aims at tailormade catalysts for the sitespecific acylation . to this end 
 , we introduce a catalyst library where each entry is constructed by connecting a variable and readily tuned peptide scaffold with a catalytically active unit based on dmap . for selected examples , 
 we demonstrate how library screening leads to the identification of optimized catalysts , and the substrates of interest can be converted with a markedly enhanced siteselectivity compared with only dmap . 
 furthermore , substrateoptimized catalysts of this type can be used to selectively convert  their  substrate in the presence of structurally similar compounds , an important requisite for reactions with mixtures of substances .