Muhammet Uyanik 교수

Over the past two decades there has been a dramatic increse in the use of hypervalent iodine compounds in synthetic organic chemistry due to their mild and selective oxidizing properties. Hypervalent iodine compounds catalyze various oxidation reactions such as the oxidation of alcohols, alpha-oxidation of ketones, oxidative spirocyclization of phenols, etc. Very recently, we found that 2-iodoxybenzensulfonic acid (IBS, ), which was generated from 2-iodobenzenesulfonic acid in situ, is an extrem

The iodines(III) have it: The rational design of a conformationally flexible C2-symmetric iodosylarene catalyst has been used for the enantioselective Kita oxidative spirolactonization. The reaction occurs through secondary n–σ* or hydrogen-bonding interactions between the chiral catalyst and the substrate. Mes=mesityl (2,4,6-trimethylphenyl). Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typ

It is desirable to minimize the use of rare or toxic metals for oxidative reactions in the synthesis of pharmaceutical products. Hypervalent iodine compounds are environmentally benign alternatives, but their catalytic use, particularly for asymmetric transformations, has been quite limited. We report here an enantioselective oxidative cycloetherification of ketophenols to 2-acyl-2,3-dihydrobenzofuran derivatives, catalyzed by in situ-generated chiral quaternary ammonium (hypo)iodite salts, with

It′s the iodine: The intra- and intermolecular title reaction is catalyzed by an in situ generated ammonium (hypo)iodite species. Either H2O2 or tert-butyl hydroperoxide (TBHP) can be used as an environmentally benign oxidant and a wide range of substrates react to give the corresponding α-acyloxycarbonyl compounds in good to excellent yields.

Electron-donating group-substituted 2-iodoxybenzoic acids (IBXs) such as 5-Me-IBX (1g), 5-MeO-IBX (1h), and 4,5-Me(2)-IBX (1i) were superior to IBX 1a as catalysts for the oxidation of alcohols with Oxone (a trademark of DuPont) under nonaqueous conditions, although Oxone was almost insoluble in most organic solvents. The catalytic oxidation proceeded more rapidly and cleanly in nitromethane. Furthermore, 2-iodoxybenzenesulfonic acid (IBS, 6a) was much more active than modified IBXs. Thus, we es

Abstract This Concept highlights the discovery and development of oxidative coupling reactions catalyzed by the hypoiodite (IO − ) or iodite (OIO − ) ion, which are generated in situ from iodide (I − ) ion with hydrogen peroxide or tert ‐butyl hydroperoxide as an environmentally benign oxidant. The most important features of these catalytic systems are 1) metal‐free oxidation, 2) milder reaction conditions, 3) high chemoselectivity (they tolerate a wide range of various functional groups), 4)

Iodine chooses: A conformationally flexible C2-symmetric organoiodine(III) catalyst for the highly enantioselective catalytic oxidative dearomatization of phenols has been developed. Catalysis is controlled by intramolecular hydrogen-bonding interactions and additional achiral alcohols.

The diverse biological activities of tocopherols and their analogs have inspired considerable interest in the development of routes for their efficient asymmetric synthesis. Here, we report that chiral ammonium hypoiodite salts catalyze highly chemo- and enantioselective oxidative cyclization of γ-(2-hydroxyphenyl)ketones to 2-acyl chromans bearing a quaternary stereocenter, which serve as productive synthetic intermediates for tocopherols. Raman spectroscopic analysis of a solution of tetrabuty

Mit Iod(III) erfolgreich: Das rationale Design eines C2-symmetrischen, chiralen Iodosylaren-Katalysators mit flexibler Konformation für die enantioselektive oxidative Kita-Spirolactonisierung beruhte auf sekundären n-σ*- oder H-Brücken-Wechselwirkungen. Mes=2,4,6-Trimethylphenyl. Detailed facts of importance to specialist readers are published as "Supporting Information". Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please

A highly enantioselective oxidative dearomatization of ortho- and para-hydroquinone derivatives to the corresponding masked ortho- and para-benzoquinones has been achieved by using chiral organoiodine(III) catalysts. Importantly, the remote steric effects of the hydrogen-bonding designer organoiodine catalysts allowed us to achieve high chemo- and enantioselectivity for the oxidative dearomatization of para-hydroquinone derivatives through an associative iodine(III)–phenoxide intermediate.

The Baeyer–Villiger (BV) oxidation of carbonyl compounds to the corresponding esters or lactones is one of the most important transformations. We recently introduced a highly efficient and selective LiB(C6F5)4- or Ca[B(C6F5)4]2-catalyzed BV oxidation of ketones with aqueous hydrogen peroxide to give the corresponding lactones in high yield. In this perspective article, we focus on our discovery and the development of BV oxidation reactions and cascade oxidative transformations through representa

A 2-iodoxybenzenesulfonic acid (IBS)-catalyzed oxidative rearrangement of tertiary allylic alcohols to enones with powdered Oxone in the presence of potassium carbonate and tetrabutylammonium hydrogen sulfate has been developed.

Highly enantioselective oxidative dearomatization of 2-naphthol derivatives was achieved for the first time by using conformationally flexible organoiodine catalysts derived from 2-aminoalcohol as a chiral source. Moreover, with the use of these catalysts, excellent enantioselectivities were also achieved for 1-naphthol derivatives, which had previously been obtained with only lower enantioselectivities. Furthermore, the product obtained from the present reaction could be transformed to a highly