Enantioselective Cis-dihydroxylation Research Articles

Mononuclear Non-Heme Manganese-Catalyzed Enantioselective cis-Dihydroxylation of Alkenes Modeling Rieske Dioxygenases.

The practical catalytic enantioselective cis-dihydroxylation of olefins that utilize earth-abundant first-row transition metal catalysts under environmentally friendly conditions is an important yet challenging task. Inspired by the cis-dihydroxylation reactions catalyzed by Rieske dioxygenases and non-heme iron models, we report the biologically inspired cis-dihydroxylation catalysis that employs an inexpensive and readily available mononuclear non-heme manganese complex bearing a tetradentate nitrogen-donor ligand and aqueous hydrogen peroxide (H2O2) and potassium peroxymonosulfate (KHSO5) as terminal oxidants. A wide range of olefins are efficiently oxidized to enantioenriched cis-diols in practically useful yields with excellent cis-dihydroxylation selectivity and enantioselectivity (up to 99% ee). Mechanistic studies, such as isotopically 18O-labeled water experiments, and density functional theory (DFT) calculations support that a manganese(V)-oxo-hydroxo (HO-MnV═O) species, which is formed via the water-assisted heterolytic O-O bond cleavage of putative manganese(III)-hydroperoxide and manganese(III)-peroxysulfate precursors, is the active oxidant that effects the cis-dihydroxylation of olefins; this is reminiscent of the frequently postulated iron(V)-oxo-hydroxo (HO-FeV═O) species in the catalytic arene and alkene cis-dihydroxylation reactions by Rieske dioxygenases and synthetic non-heme iron models. Further, DFT calculations for the mechanism of the HO-MnV═O-mediated enantioselective cis-dihydroxylation of olefins reveal that the first oxo attack step controls the enantioselectivity, which exhibits a high preference for cis-dihydroxylation over epoxidation. In this study, we are able to replicate both the catalytic function and the key chemical principles of Rieske dioxygenases in mononuclear non-heme manganese-catalyzed enantioselective cis-dihydroxylation of olefins.

Nonheme Iron-Catalyzed Enantioselective cis -Dihydroxylation of Aliphatic Acrylates as Mimics of Rieske Dioxygenases

Open AccessCCS ChemistryRESEARCH ARTICLE17 Feb 2022Nonheme Iron-Catalyzed Enantioselective cis-Dihydroxylation of Aliphatic Acrylates as Mimics of Rieske Dioxygenases Jie Chen, Xiu Luo, Ying Sun, Si Si, Yuankai Xu, Yong-Min Lee, Wonwoo Nam and Bin Wang Jie Chen Google Scholar More articles by this author , Xiu Luo Google Scholar More articles by this author , Ying Sun Google Scholar More articles by this author , Si Si Google Scholar More articles by this author , Yuankai Xu Google Scholar More articles by this author , Yong-Min Lee Google Scholar More articles by this author , Wonwoo Nam Google Scholar More articles by this author and Bin Wang Google Scholar More articles by this author https://doi.org/10.31635/ccschem.022.202101780 SectionsSupplemental MaterialAboutPDF ToolsAdd to favoritesTrack Citations ShareFacebookTwitterLinked InEmail Enantioselective cis-dihydroxylation of alkenes represents an ideal route to synthesize enantioenriched syn-2,3-dihydroxy esters that are important structural motifs in numerous biologically and pharmaceutically relevant molecules. Bioinspired nonheme iron-catalyzed enantioselective cis-dihydroxylation meets the requirement of the modern synthetic chemistry from atomic economy, green chemistry and sustainable development perspectives. However, nonheme iron-catalyzed enantioselective cis-dihydroxylation is much underdeveloped because of the formidable challenges of controlling chemo- and enantioselectivities and product selectivity caused from the competitive epoxidation, cis-dihydroxylation and overoxidation reactions. Herein, we disclose a biologically inspired nonheme iron complex-catalyzed enantioselective cis-dihydroxylation of multi-substituted acrylates using hydrogen peroxide (H2O2) as a terminal oxidant by controlling the non-ligating or weakly ligating counterions of iron(II) complexes; we have demonstrated a dramatic counteranion effect on the enantioselective cis-dihydroxylation of olefins by H2O2 catalyzed by nonheme iron complexes. A range of structurally disparate alkenes are transformed to the corresponding syn-2,3-dihydroxy esters in practically useful yields with exquisite chemo- and enantioselectivities (up to 99% ee). Given the mild and benign nature of this biologically inspired oxidation system and the ubiquity and synthetic utility of enantioenriched syn-2,3-dihydroxy esters in pharmaceuticals candidates and natural products, we expect that this strategy to some extent can serve as a promising compliment to the well-known Sharpless asymmetric dihydroxylation. Download figure Download PowerPoint Next article FiguresReferencesRelatedDetails Issue AssignmentNot Yet AssignedSupporting Information Copyright & Permissions© 2022 Chinese Chemical Society Downloaded 0 times Loading ...

Iron-Catalyzed Highly Enantioselective cis-Dihydroxylation of Trisubstituted Alkenes with Aqueous H2 O2.

Reliable methods for enantioselective cis-dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis-α-[FeII (2-Me2 -BQPN)(OTf)2 ], which bears a tetradentate N4 ligand (Me2 -BQPN=(R,R)-N,N'-dimethyl-N,N'-bis(2-methylquinolin-8-yl)-1,2-diphenylethane-1,2-diamine), was prepared and characterized. With this complex as the catalyst, a broad range of trisubstituted electron-deficient alkenes were efficiently oxidized to chiral cis-diols in yields of up to 98 % and up to 99.9 % ee when using hydrogen peroxide (H2 O2 ) as oxidant under mild conditions. Experimental studies (including 18 O-labeling, ESI-MS, NMR, EPR, and UV/Vis analyses) and DFT calculations were performed to gain mechanistic insight, which suggested possible involvement of a chiral cis-FeV (O)2 reaction intermediate as an active oxidant. This cis-[FeII (chiral N4 ligand)]2+ /H2 O2 method could be a viable green alternative/complement to the existing OsO4 -based methods for asymmetric alkene dihydroxylation reactions.

OsO4⋅Streptavidin: A Tunable Hybrid Catalyst for the Enantioselective cis-Dihydroxylation of Olefins

Gut kombiniert: Die Kombination von Apostreptavidin mit OsO4 lieferte selektive Katalysatoren für die Olefindihydroxylierung. Durch ortsgerichtete Mutagenese gelang eine Verbesserung der Enantioselektivität und in bestimmten Fällen sogar eine Umkehr der Enantiopräferenz. Vor allem Allylphenylsulfid und cis-β-Methylstyrol wurden mit bislang unerreichtem Enantiomerenüberschuss umgesetzt.

Practical manganese-catalysed highly enantioselective cis-dihydroxylation of electron-deficient alkenes and detection of a cis-dioxomanganese(v) intermediate by high resolution ESI-MS analysis

A practical protocol has been developed for asymmetric cis-dihydroxylation of electron-deficient alkenes with Oxone catalysed by a manganese complex bearing a chiral tetradentate N(4)-donor ligand affording cis-diols in up to 95% yield with up to 96% ee. Analysis of the reaction mixture by high resolution ESI-MS revealed the formation of a cis-dioxomanganese(V) intermediate.

Natural product chemistry. Part 181. Investigations on the synthesis of dihydropyrano- and dihydrofurano-coumarins by application of catalytic enantioselective cis-dihydroxylation

As part of a study on the applicability of catalytic enantioselective cis-dihydroxylation for the synthesis of dihydropyrano- and dihydrofurano-anellated coumarins new routes to (–)-cis-khellactone 1b, (–)-trans-khellactone 1c and rutartein 4 have been developed.

A simplified procedure for the stereospecific transformation of 1,2-diols into epoxides

A simple, ‘one-pot’ procedure for the conversion of vicinal diols into epoxides via halohydrin ester intermediates has been developed. This method tolerates a wide range of functionality including acid sensitive functional groups. The transformation proceeds via a, usually highly regioselective, nucleophilic opening of a cyclic acetoxonium intermediate, generated from a cyclic orthoacetate and Me 3SiCl, acetyl bromide or acetyl chloride/NaI to form 1-acetoxy-2-chloride, 1-acetoxy-2-bromide or 1-acetoxy-2-iodide intermediates, respectively. No epimerization occurs, even with benzylic substrates. Subsequent base mediated methanolysis furnishes epoxides in excellent overall yield. Application of this method led to an efficient formal synthesis of the leukotriene antagonist SKF 104353, commencing with the highly enantioselective cis-dihydroxylation of methyl 3-[2-(8-phenyloctyl)phenyl]propenoate.