title: Polymer- and silica-supported iron BPMEN-inspired catalysts for C-H bond functionalization reactions.
abstract: Direct catalytic C-H bond functionalization is a key challenge in synthetic chemistry, with many popular C-H activation methodologies involving precious-metal catalysts. In recent years, iron catalysts have emerged as a possible alternative to the more common precious-metal catalysts, owing to its high abundance, low cost, and low toxicity. However, iron catalysts are plagued by two key factors: the ligand cost and the low turnover numbers (TONs) typically achieved. In this work, two approaches are presented to functionalize the popular N(1),N(2)-dimethyl-N(1),N(2)-bis(pyridin-2-ylmethyl)ethane-1,2-diamine (BPMEN) ligand, so that it can be supported on porous silica or polymer resin supports. Four new catalysts are prepared and evaluated in an array of catalytic C-H functionalization reactions by using cyclohexane, cyclohexene, cyclooctane, adamantane, benzyl alcohol, and cumene with aqueous hydrogen peroxide. Catalyst recovery and recycling is demonstrated by using supported catalysts, which allows for a modest increase in the TON achieved with these catalysts.
authors.affiliation: School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Dr., Atlanta, GA 30332 (USA).
authors.forename: Yan
authors.initials: Y
authors.lastname: Feng
authors.forename: Eric G
authors.initials: EG
authors.lastname: Moschetta
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Jones
keywords: CH activation; hydroxylation; immobilization; iron; supported catalysts