58740-82-2

Usage

Molecular Class

Oxirenochromene

Molecular Structure

Seven-membered ring fused to a six-membered ring with an epoxy group

Complexity

Complex organic compound

Potential Applications

Medicinal chemistry and drug discovery

Reasons for Interest

Structural diversity and potential biological activities

Research Focus

Synthesis and properties in organic chemistry

Study Subjects

Molecular structure and chemical and physical properties

Upstream product

• 2513-25-9 2,2-dimethyl-2H-chromene 
• 180303-21-3 (1S,4R)-4,7,7-Trimethyl-3-oxo-2-oxa-bicyclo[2.2.1]heptane-1-carboxylic acid (3S,4R)-3-bromo-2,2-dimethyl-chroman-4-yl ester 
• 3780-33-4 2,3-dihydro-2,2-dimethylbenzo[b]pyran-4-one 
• 71649-83-7 3,4-dihydro-4-hydroxy-2,2-dimethyl-2H-benzo[b]pyran 
• 17235-15-3 (E)-2-(3-hydroxy-3-methylbut-1-en-1-yl)phenol 
• 3975-15-3 (+/-)-(3S,4R)-3-bromo-2,2-dimethyl-3,4-dihydro-2H-chromen-4-ol 
• 33143-29-2 6-cyano-2,2-dimethylchromene 
• 180469-88-9 (1S,4R)-4,7,7-Trimethyl-3-oxo-2-oxa-bicyclo[2.2.1]heptane-1-carboxylic acid (3R,4S)-3-bromo-2,2-dimethyl-chroman-4-yl ester 

Relevant academic research and scientific papers

Synthesis of new chiral Mn(iii)-salen complexes as recoverable and reusable homogeneous catalysts for the asymmetric epoxidation of styrenes and chromenes

New chiral Mn(iii)-salen complexes 1a-e and 2a-e were synthesized from the reaction of C2-symmetric chiral salen ligands and Mn(CH3COO)2·4H2O under an inert atmosphere followed by aerobic oxidation. These complexes were obtained in 91-96% yields and characterized by HRMS, FT-IR, UV-visible spectroscopy, TGA, and elemental analysis. The chiral Mn(iii)-salen complexes 1a-e and 2a-e were evaluated in the asymmetric epoxidation of styrene using NaOCl as an oxidant in ethyl acetate as a green solvent. The chiral Mn(iii)-salen complexes 1b and 2b (2 mol%) catalyzed the asymmetric epoxidation of substituted styrenes and chromenes to afford the corresponding epoxides in 95-98% yields with 29-88% ee's. The catalysts 1b and 2b were recovered and reused for up to 2 and 3 runs, respectively, in the asymmetric epoxidation of styrene, and the yield of styrene oxide gradually decreased but the ee was consistent.

Design and assembly of a chiral composite metal-organic framework for efficient asymmertric sequential transformation of alkenes to amino alcohols

In this work, we report the successful construction of two chiral porous metal-metallosalan frameworks (1 and 2) by using dipyridylfunctionalized chiral Al(salen) and Mn(salen) separately, and then a composite crystal MOF 3 was constructed with 1 inside, which was encapsulated by 2 outside. The resulting composite crystal appeared to be highly enantioselective for the alkene epoxidation/epoxide aminolysis reactions with a maximum ee of 97%.

Design and Assembly of Chiral Coordination Cages for Asymmetric Sequential Reactions

Supramolecular nanoreactors featuring multiple catalytically active sites are of great importance, especially for asymmetric catalysis, and are yet challenging to construct. Here we report the design and assembly of five chiral single- and mixed-linker tetrahedral coordination cages using six dicarboxylate ligands derived-from enantiopure Mn(salen), Cr(salen) and/or Fe(salen) as linear linkers and four Cp3Zr3 clusters as three-connected vertices. The formation of these cages was confirmed by a variety of techniques including single-crystal and powder X-ray diffraction, inductively coupled plasma optical emission spectrometer, quadrupole-time-of-flight mass spectrometry and energy dispersive X-ray spectrometry. The cages feature a nanoscale hydrophobic cavity decorated with the same or different catalytically active sites, and the mixed-linker cage bearing Mn(salen) and Cr(salen) species is shown to be an efficient supramolecular catalyst for sequential asymmetric alkene epoxidation/epoxide ring-opening reactions with up to 99.9% ee. The cage catalyst demonstrates improved activity and enantioselectivity over the free catalysts owing to stabilization of catalytically active metallosalen units and concentration of reactants within the cavity. Manipulation of catalytic organic linkers in cages can control the activities and selectivities, which may provide new opportunities for the design and assembly of novel functional supramolecular architectures.

Design and Assembly of a Chiral Metallosalen-Based Octahedral Coordination Cage for Supramolecular Asymmetric Catalysis

Supramolecular containers featuring both high catalytic activity and high enantioselectivity represent a design challenge of practical importance. Herein, it is demonstrated that a chiral octahedral coordination cage can be constructed by using twelve enantiopure Mn(salen)-derived dicarboxylic acids as linear linkers and six Zn4-p-tert-butylsulfonylcalix[4]arene clusters as tetravalent four-connected vertices. The porous cage features a large hydrophobic cavity (≈3944 ?3) decorated with catalytically active metallosalen species and is shown to be an efficient and recyclable asymmetric catalyst for the oxidative kinetic resolution of racemic secondary alcohols and the epoxidation of olefins with up to >99 % enantiomeric excess. The cage architecture not only prevents intermolecular deactivation and stabilizes the Mn(salen) catalysts but also encapsulates substrates and concentrates reactants in the cavity, resulting in enhanced reactivity and enantioselectivity relative to the free metallosalen catalyst.

Controlled Exchange of Achiral Linkers with Chiral Linkers in Zr-Based UiO-68 Metal-Organic Framework

The development of highly robust heterogeneous catalysts for broad asymmetric reactions has always been a subject of interest, but it remains a synthetic challenge. Here we demonstrated that highly stable metal-organic frameworks (MOFs) with potentially acid-labile chiral catalysts can be synthesized via postsynthetic exchange. Through a one- or two-step ligand exchange, a series of asymmetric metallosalen catalysts with the same or different metal centers are incorporated into a Zr-based UiO-68 MOF to form single- and mixed-M(salen) linker crystals, which cannot be accomplished by direct solvothermal synthesis. The resulting MOFs have been characterized by a variety of techniques including single-crystal X-ray diffraction, N2 sorption, CD, and SEM/TEM-EDS mapping. The single-M(salen) linker MOFs are active and efficient catalysts for asymmetric cyanosilylation of aldehydes, ring-opening of epoxides, oxidative kinetic resolution of secondary alcohols, and aminolysis of stilbene oxide, and the mixed-M(salen) linker variants are active for sequential asymmetric alkene epoxidation/epoxide ring-opening reactions. The chiral MOF catalysts are highly enantioselective and completely heterogeneous and recyclable, making them attractive catalysts for eco-friendly synthesis of fine chemicals. This work not only advances UiO-type MOFs as a new platform for heterogeneous asymmetric catalysis in a variety of syntheses but also provides an attractive strategy for designing robust and versatile heterogeneous catalysts.

Multivariate Metal-Organic Frameworks as Multifunctional Heterogeneous Asymmetric Catalysts for Sequential Reactions

The search for versatile heterogeneous catalysts with multiple active sites for broad asymmetric transformations has long been of great interest, but it remains a formidable synthetic challenge. Here we demonstrate that multivariate metal-organic frameworks (MTV-MOFs) can be used as an excellent platform to engineer heterogeneous catalysts featuring multiple and cooperative active sites. An isostructural series of 2-fold interpenetrated MTV-MOFs that contain up to three different chiral metallosalen catalysts was constructed and used as efficient and recyclable heterogeneous catalysts for a variety of asymmetric sequential alkene epoxidation/epoxide ring-opening reactions. Interpenetration of the frameworks brings metallosalen units adjacent to each other, allowing cooperative activation, which results in improved efficiency and enantioselectivity over the sum of the individual parts. The fact that manipulation of molecular catalysts in MTV-MOFs can control the activities and selectivities would facilitate the design of novel multifunctional materials for enantioselective processes.

Chiral Covalent Organic Frameworks with High Chemical Stability for Heterogeneous Asymmetric Catalysis

Covalent organic frameworks (COFs) featuring chirality, stability, and function are of both fundamental and practical interest, but are yet challenging to achieve. Here we reported the metal-directed synthesis of two chiral COFs (CCOFs) by imine-condensat

Self-supported chiral polymeric MnIII salen complexes as highly active and recyclable catalysts for epoxidation of nonfunctionalized olefins

Abstract A series of self-supported chiral polymeric MnIII N,N′-ethylenebis(salicylimine) (salen) complexes were synthesized through metalation of the corresponding salen ligands obtained by condensation of several bis/tris-aldehydes with (1R,2

Towards heterogeneous organocatalysis: Chiral iminium cations supported on porous materials for enantioselective alkene epoxidation

Enantiomerically pure iminium cations have been supported on a microporous support (zeolite Y) and on a mesoporous support (Al-MCM-41). These materials are effective asymmetric catalysts for the epoxidation of a range of aryl alkenes, giving high conversions quickly and with enantioselectivities similar to or in some cases even higher than are achievable using the corresponding iminium tetraphenylborates under homogeneous conditions. The catalysts can be simply recycled by filtration and washing. The methodology is illustrated in the synthesis of two natural products, (-)-(3′S)-lomatin and (+)-(3′S,4′R)-trans-khellactone, showing the general efficacy of our approach. The Royal Society of Chemistry 2013.

Organic carbonates as solvents in macrocyclic Mn(III) salen catalyzed asymmetric epoxidation of non-functionalized olefins

Organic carbonates, e.g., dimethyl carbonate and propylene carbonate were used as reaction media in enantioselective epoxidation of non-functionalized alkenes by using a series of chiral macrocyclic Mn(III) salen complexes (5 mol%) as catalyst with pyridi