Common Epoxide Research Articles

Synthesis of bio-based polyesters from carvone-derived epoxides

Degradable polymers synthesized from biomasses have become increasingly appealing for their environmentally friendly and sustainable features. In this study, (R)-(−)-carvone, a natural monoterpene, and its hydrogenated derivative, (+)-dihydrocarvone, are oxidized to afford two epoxy compounds, termed as EK and MOO, respectively. The epoxides are subject to ring-opening copolymerization with cyclic anhydrides, including phthalic anhydride and cis-5-norbornene-exo-2,3-dicarboxylic anhydride, organocatalyzed by a phosphazene base. High or complete anhydride conversion can be reached at 100 °C when the epoxides are used in slight excesses. The resulting polyesters exhibit fully alternating sequence distribution, high glass transition temperature (108–142 °C), and two-step thermal degradation (above 200 °C) which is distinct from the polyesters derived from common epoxides. Compared with EK, MOO allows better controlled and distinctly higher molar mass (>10 kg mol−1), indicating much less profound (intramolecular) transesterification occurring on the polyester backbone. Most interestingly, the lactone moiety of MOO, generated together with the epoxide moiety by oxidation and previously shown polymerizable, stays intact during the copolymerization, which may constitute a simple strategy for utilizing bio-sourced bifunctional compounds chemoselectively and/or orthogonally.

A Chiral Titanocene Complex as Regiodivergent Photoredox Catalyst: Synthetic Scope and Mechanism of Catalyst Generation.

We describe a combined synthetic, spectroscopic, and computational study of a chiral titanocene complex as a regiodivergent photoredox catalyst (PRC). With Kagan's complex catCl2 either monoprotected 1,3-diols or 1,4-diols can be obtained in high selectivity from a common epoxide substrate in a regiodivergent epoxide opening depending on which enantiomer of the catalyst is employed. Due to the catalyst-controlled regioselectivity of ring opening and the broader substrate scope, the PRC with catCl2 is also a highly attractive branching point for diversity-oriented synthesis. The photochemical processes of cat(NCS)2, a suitable model for catCl2, were probed by time-correlated single-photon counting. The photoexcited complex displays a thermally activated delayed fluorescence as a result of a singlet-triplet equilibration, S1 ⇄ T1, via intersystem crossing and recrossing. Its triplet state is quenched by electron transfer to the T1 state. Computational and cyclic voltammetry studies highlight the importance of our sulfonamide additive. By bonding to sulfonamide additives, chloride abstraction from [catCl2]- is facilitated, and catalyst deactivation by coordination of the sulfonamide group is circumvented.

Neogrisemycin, a Trisulfide-Bridged Angucycline, Produced upon Expressing the Thioangucycline Biosynthetic Gene Cluster in Streptomyces albus J1074.

Neogrisemycin (1) was isolated from recombinant Streptomyces albus J1074 strain SB4061 expressing an engineered thioangucycline (TAC) biosynthetic gene cluster (BGC). The structure and absolute configuration of 1 were established by a combination of mass spectrometry, nuclear magnetic resonance, and single-crystal X-ray diffraction analyses. Like the TACs, 1 was also proposed to derive non-enzymatically from the common epoxide (8), the nascent product encoded by the tac BGC, mediated by endogenous hydrogen trisulfide.

Synthesis of poly(1,2-butylene oxide-stat-tetrahydrofuran) by controllable polymerization over Sc(OTf)3 for use in high-performance lubricating oil

Aliphatic polyethers are synthesized byring-opening polymerization (ROP) of the most common epoxide monomers, such as ethylene oxide (EO) and propylene oxide (PO). 1,2-Butylene oxide (BO) and tetrahydrofuran (THF) are potentially extended ROP monomers, which can give polyether unique properties. In this work, a series of poly(1,2-butylene oxide-stat-tetrahydrofuran)s (PBO-stat-PTHFs) with Mn of 900–3700 g·mol−1 were synthesized by cationic ring-opening polymerization (CROP) of BO with THF using strong Lewis acid Rare Earth triflates (RE(OTf)3) as catalysts and diols as an initiator at room temperature. PBO-stat-PTHFs product with yield up to 90 %, narrow polydispersity of Đ <1.30, and molar ratio of PBO to PTHF 1:1 were obtained. The copolymerization process was studied by in-situ IR and 1H NMR spectroscopy analysis, and the results showed that PBO-stat-PTHF is a statistical copolymer. The early stage of the polymerization reaction was dominated by the activated chain end mechanism (ACEM), which incorporates a large amount of THF into the polymer chains. However, the late stage of the polymerization reaction was dominated by the activated monomer mechanism (AMM), which incorporates a large amount of BO into the polymer chains. Most PBO-stat-PTHFs have a suitable Mn range, super high viscosity index (≥198) and low pour point (≤-53 °C), which can be used as a lubricant base oil and additives. In addition, PBO-stat-PTHFs have excellent miscibility with polyalphaolefin (PAO), which could significantly improve the PAO viscosity index. This study provides a mild route to construct high-performance copolyether materials through cationic ring-opening controllable polymerization.

Unexpected Reactions of α,β-Unsaturated Fatty Acids Provide Insight into the Mechanisms of CYP152 Peroxygenases.

CYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2 O2 as cofactor. To understand the molecular basis for the chemo- and regioselectivity of these unique P450 enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE , P450SPα , P450BSβ ) towards cis- and trans-dodecenoic acids as substrate probes. The unexpected 6S-hydroxylation of the trans-isomer and 4R-hydroxylation of the cis-isomer by OleTJE , and molecular docking results suggest that the unprecedented selectivity is due to OleTJE 's preference of C2-C3 cis-configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans-configuration of substrates. The combined H218 O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I-mediated aldehyde formation in which the active site water derived from H2 O2 activation is involved in the generation of a four-membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.

Unexpected Reactions of α,β‐Unsaturated Fatty Acids Provide Insight into the Mechanisms of CYP152 Peroxygenases

AbstractCYP152 peroxygenases catalyze decarboxylation and hydroxylation of fatty acids using H2O2 as cofactor. To understand the molecular basis for the chemo‐ and regioselectivity of these unique P450 enzymes, we analyze the activities of three CYP152 peroxygenases (OleTJE, P450SPα, P450BSβ) towards cis‐ and trans‐dodecenoic acids as substrate probes. The unexpected 6S‐hydroxylation of the trans‐isomer and 4R‐hydroxylation of the cis‐isomer by OleTJE, and molecular docking results suggest that the unprecedented selectivity is due to OleTJE’s preference of C2−C3 cis‐configuration. In addition to the common epoxide products, undecanal is the unexpected major product of P450SPα and P450BSβ regardless of the cis/trans‐configuration of substrates. The combined H218O2 tracing experiments, MD simulations, and QM/MM calculations unravel an unusual mechanism for Compound I‐mediated aldehyde formation in which the active site water derived from H2O2 activation is involved in the generation of a four‐membered ring lactone intermediate. These findings provide new insights into the unusual mechanisms of CYP152 peroxygenases.

Collective enantioselective total synthesis of (+)-sinensilactam A, (+)-lingzhilactone B and (-)-lingzhiol: divergent reactivity of styrene.

The collective total synthesis of (+)-sinensilactam A, (+)-lingzhilactone B, (+)-lingzhilactone C and (-)-lingzhiol has been accomplished from a common epoxide intermediate 9. Chemoselective epoxy opening with either an aryl or alkene moiety of styrene led to different carbon skeletons, which can be advanced to a divergent and concise total synthesis of four meroterpenoids.

Multiarm Polycarbonate Star Polymers with a Hyperbranched Polyether Core from CO2 and Common Epoxides

Multiarm star copolymers, consisting of hyperbranched poly(ethylene oxide) (hbPEO) or poly(butylene oxide) (hbPBO) polyether copolymers with glycerol branching points as a core, and linear aliphatic polycarbonate arms generated from carbon dioxide (CO2) and epoxide monomers, were synthesized via a “core-first” approach in two steps. First, hyperbranched polyether polyols were prepared by anionic copolymerization of ethylene oxide or 1,2-butylene oxide with 8–35% glycidol with molecular weights between 800 and 389,000 g·mol–1. Second, multiple arms were grown via immortal copolymerization of CO2 with propylene oxide or 1,2-butylene oxide using the polyether polyols as macroinitiators and (R,R)-(salcy)-CoCl as a catalyst in a solvent-free procedure. Molecular weights up to 812,000 g·mol–1 were obtained for the resulting multiarm polycarbonates, determined by online viscometry with universal calibration and 1H NMR. Comparing the synthesis of different multiarm star polycarbonates, a combination of a highly r...

General, Highly Selective Synthesis of 1,3‐ and 1,4‐Difunctionalized Building Blocks by Regiodivergent Epoxide Opening

AbstractWe describe a regiodivergent epoxide opening (REO) featuring a catalyst‐controlled synthesis of enantiomerically and diastereomerically highly enriched or pure syn‐ and anti‐ 1,3‐ and 1,4‐difunctionalized building blocks from a common epoxide precursor. The REO is attractive for natural product synthesis and as a branching reaction for diversity‐oriented synthesis with epoxides.

General, Highly Selective Synthesis of 1,3- and 1,4-Difunctionalized Building Blocks by Regiodivergent Epoxide Opening.

We describe a regiodivergent epoxide opening (REO) featuring a catalyst-controlled synthesis of enantiomerically and diastereomerically highly enriched or pure syn- and anti- 1,3- and 1,4-difunctionalized building blocks from a common epoxide precursor. The REO is attractive for natural product synthesis and as a branching reaction for diversity-oriented synthesis with epoxides.

ChemInform Abstract: Preparation of Enantioenriched Tetraols and Triolamines from a Common Epoxide.

AbstractThe desymmetrization of meso epoxide (I) with nitrogen or oxygen nucleophiles is developed by using Jacobsen‐type catalysts.

Preparation of enantioenriched tetraols and triolamines from a common epoxide

Abstract We identify a silylcyclopentene oxide that is amenable to several distinct asymmetric catalytic transformations providing access to enantio-enriched tetraol and triol-amines. The sequence employed allows for selective protection of one amine or alcohol from the four heteroatoms that are introduced into the carbon scaffold.

Influence of solvent washing on interlayer structure of alkylammonium montmorillonites

Powdered samples of montmorillonite were functionalized with alkylammonium ions of various chain lengths and subjected to two different constant volume washing procedures: water only or sequential ethanol–water. The alkylammonium montmorillonites were analyzed with X-ray diffraction and differential scanning calorimetry to obtain insights into the effect of washing procedure. The ethanol–water procedure greatly reduced the amount of surfactant present that was not bound by cation exchange, and in some instances affected the crystallinity of the surfactant. Additionally, contact angle measurements on the compacted alkylammonium montmorillonites were obtained to assess the effect of functionalization and washing on the wettability of two common epoxides used in clay–epoxy nanocomposites. Regardless of surfactant treatment, the alkylammonium montmorillonites with ethanol–water washing exhibited lower contact angles for the epoxides, which is consistent with lower final surfactant content.

New Building Block for Polyhydroxylated Piperidine: Total Synthesis of 1,6-Dideoxynojirimycin

(3R,4S)-3-Hydroxy-4-N-allyl-N-Boc-amino-1-pentene 10, an important precursor for the synthesis of polyhydroxylated piperidines, has been achieved as a single diastereomer without racemization via vinyl Grignard addition to N-Boc-N-allyl aminoaldehyde 9, which was derived from an enantiopure natural amino acid. Having forged a tetrahydropyridine ring scaffold 13 from 10 in 85% yield via RCM using Grubbs II catalyst, we were able to effect its stereodivergent dihydroxylation, via a common epoxide intermediate to yield a range of interesting hydroxylated piperidines, including ent-1,6-dideoxynojirimycin (ent-1,6-dDNJ) 1 (28% overall yield) and 5-amino-1,5,6-trideoxyaltrose 2 (29% over all yield) in excellent dr. To the best of our knowledge, our synthesis of ent-1,6-dDNJ 1 is the most expeditious to date.

How Rapidly Do Epoxides Nonspecifically Form Covalent Bonds with Thiols in Water?

How Rapidly Do Epoxides Nonspecifically Form Covalent Bonds with Thiols in Water?

Selective synthesis of α-chloroepoxides by electroreductive cross-coupling of methyl trichloroacetate with aliphatic aldehydes using reactive metal anodes

It was found in this study that electroreductive cross-coupling of methyl trichloroacetate with aliphatic aldehydes using a reactive metal anode gave the corresponding α-chloroepoxides, useful synthetic intermediates, selectively in good yields. Furthermore, as a synthetic application to organic synthesis, these specific products were subjected to typical reduction with metal hydride reagents and condensation with o-phenylenediamine, showing that they have several interesting reactivities different from those of common epoxides.

Total Synthesis of Acanthacerebroside A and Astrocerebroside A via a Chiral Epoxide Intermediate Derived from l-Quebrachitol

Abstract The chiral and stereoselective total synthesis of novel cerebrosides, acanthacerebroside A (1) and astrocerebroside A (2), isolated from starfish, is described. The phytosphingosine moieties in 1 and 2 were prepared by the coupling reaction of dialkylmagnesium reagents with the common epoxide intermediate, 2-(t-butoxycarbonyl)amino-1-O-(t-butyldiphenylsilyl)-2-deoxy-3-O-(4-methoxybenzyl)-d-4,5-anhydroribitol (5). The epoxide (5) was synthesized from naturally occurring cyclitol, l-quebrachitol via the conduramine derivative, which was prepared regio- and stereoselectively by the Pd-catalyzed azidation of the allyl carbonate derivative. Condensation of phytosphingosines with 2-acetoxy fatty acid residue, followed by glycosidation, furnished the total synthesis. This work established an effective synthetic pathway to a wide variety of cerebrosides containing various phytosphingosines and 2-hydroxy fatty acid residue; the first total synthesis of astrocerebroside A (2) fully confirmed the proposed structure.

3-Phenyl-2,7-naphthyridin-1(2H)-one as a New Fluorogenic Reagent for Epoxides and Its Application to Determination of Trichothecene Mycotoxins

A fluorescence reaction of epoxides with 3-phenyl-2, 7-naphthyridin-1(2H)-one (PNO) is described. Common epoxides and 12, 13-epoxytrichothecenes gave a green fluorescence (λex 441-467nm and λem 506-510nm) after reaction with PNO at 120°C for 90min in 1, 2-ethanediol/2- methoxyethanol mixture for the former and at 150°C for 30min on a solid phase for the latter, respectively, and followed by addition of N, N-dimethylformamide in both the cases. By the proposed methods, as little as 20-30pmol of common epoxides and 64-85pmol of trichothecenes could be determined with relative standard deviations of ranges 1.7-4.3% and 4.8-8.6%, respectively.

Spectrofluorometric determination of common epoxides with sodium sulfide and o-phthalaldehyde and taurine reagents

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpectrofluorometric determination of common epoxides with sodium sulfide and o-phthalaldehyde and taurine reagentsAkira. Sano and Shoji. TakitaniCite this: Anal. Chem. 1985, 57, 8, 1687–1690Publication Date (Print):July 1, 1985Publication History Published online1 May 2002Published inissue 1 July 1985https://doi.org/10.1021/ac00285a039RIGHTS & PERMISSIONSArticle Views161Altmetric-Citations6LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (515 KB) Get e-Alerts Get e-Alerts

4-Acetylpyridine 2-Benzothiazolylhydrazone as a Chromogenic Reagent for Common Epoxides

Abstract A simple and sensitive color reaction of common epoxides as well as other some alkylating agents with 4-acetylpyrldine 2-benzothiazolylhydrazone (ABH) is described. These compounds gave a purpllsh red color after reaction with ABH for 2 hrs at 110°C in methyl cellosolve or for 20 min at 120°C followed by treatment with plperazlne on silica gel thin-layer plates. Four aliphatic terminal epoxides could be determined spectrophotometrically in the range from 20 to 125 nmol/ml. The limits of detection of these epoxides on silica gel thin-layer plates were 10 pmol/spot order by the visual inspection. The reaction mechanism is also discussed based on the chemical structure of the isolated chromophore.