title: Turning on catalysis: incorporation of a hydrogen-bond-donating squaramide moiety into a Zr metal-organic framework.
abstract: Herein, we demonstrate that the incorporation of an acidic hydrogen-bond-donating squaramide moiety into a porous UiO-67 metal-organic framework (MOF) derivative leads to dramatic acceleration of the biorelevant Friedel-Crafts reaction between indole and β-nitrostyrene. In comparison, it is shown that free squaramide derivatives, not incorporated into MOF architectures, have no catalytic activity. Additionally, using the UiO-67 template, we were able to perform a direct comparison of catalytic activity with that of the less acidic urea-based analogue. This is the first demonstration of the functionalization of a heterogeneous framework with an acidic squaramide derivative.
authors.affiliation: Department of Chemistry and the International Institute for Nanotechnology, Northwestern University , 2145 Sheridan Road, Evanston, Illinois 60208-3113, United States.
authors.forename: C Michael
authors.initials: CM
authors.lastname: McGuirk
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Katz
authors.forename: Charlotte L
authors.initials: CL
authors.lastname: Stern
authors.forename: Amy A
authors.initials: AA
authors.lastname: Sarjeant
authors.forename: Joseph T
authors.initials: JT
authors.lastname: Hupp
authors.forename: Omar K
authors.initials: OK
authors.lastname: Farha
authors.forename: Chad A
authors.initials: CA
authors.lastname: Mirkin