Oxidizing Polymers: A Polymer-Supported, Recyclable Hypervalent Iodine(V) Reagent for the Efficient Conversion of Alcohols, Carbonyl Compounds, and Unsaturated Carbamates in Solution J.R. gratefully acknowledges generous support from Prof. M. E. Maier, Tübingen, the Strukturfonds of the University of Tübingen, the Fonds der Chemischen Industrie, and the DFG. We thank Graeme Nicholson, Dietmar Schmid, and Daniel Bischoff for analytical support.

Abstract

The oxidation of various alcohols and cyclization of an olefinic carbamate succeeds with the first polymer‐supported iodine(V) reagent (see scheme). The novel oxidizing polymer oxidizes sensitive and complex alcohols, including protected amino alcohols, efficiently in good to excellent yields. In addition, the α,β‐dehydration of a ketone is demonstrated.

Catalytic Version of and Reuse in Hypervalent Organo‐λ3‐ and ‐λ5‐iodane Oxidation

“…The chemistry of polymer‐supported aryl‐λ 5 ‐iodanes was summarized in reviews by Togo in 200230 and by Zhdankin in 200652 and 2007 53. In 2001, Giannis's54 and Rademann's groups55 reported the first syntheses of immobilized aryl‐λ 5 ‐iodanes: the aminopropylsilica gel‐supported IBX 41 and the Merrifield resin‐supported IBX 42 , respectively. Scheme shows the structures of immobilized aryl‐λ 5 ‐iodanes prepared so far with their reference numbers.…”

Polystyrene-Supported (Catecholato)oxorhenium Complexes: Catalysts for Alcohol Oxidation with DMSO and for Deoxygenation of Epoxides to Alkenes with Triphenylphosphine

“…Polymer-supported reagents/ catalysts for alcohol oxidation are particularly important for applications in parallel solution-phase synthesis, where product purification can be facilitated by simple filtration. Recently, a derivative of the widely used periodinane oxidant 2-iodoxybenzoic acid was rendered heterogeneous by attachment to a polystyrene support, and this reagent was used for the oxidation of various alcohols [16]. Immobilized 2,2,6,6-tetramethylpiperidin-1-yloxyl (TEMPO) nitroxyl radicals were shown to be efficient catalysts for alcohol oxidation with hypochlorite, and preferential selectivity for primary alcohols in the presence of secondary alcohols was exhibited [17 ± 19].…”

First Synthesis of Argadin: A Nanomolar Inhibitor of Family‐18 Chitinases

“…MS analysis was consistent with the expected formation of two diastereoisomeric hemiaminals, with 1 H and 13 C NMR spectroscopic data for the major diastereoisomer being indistinguishable from those reported by Omura et al11 While numerous examples of peptide natural products containing a homologous glutamic acid‐derived hemiaminal have been reported,24 to the best of our knowledge, this is the first example of the synthesis of such a molecule incorporating the five‐membered variant. The oxidation could also be performed using polystyrene‐supported IBX,25 however the rate of conversion was very slow (approx. 10 % conversion after 5 d).…”