How to predict the regioselectivity of epoxide ring opening. High reactivity with various nucleophiles leads to high regioselective and transstereospecific ring opening products. Amino alcohols by regioselective ring opening of epoxides with aromatic amines catalyzed by tin ii chloride 1, 3. Regioselective ring opening of aliphatic and aromatic epoxides with nitrogen heterocycles such as indoles and imidazoles was accelerated using an ultrasonic technique as a green approach. Metalorganic frameworks as efficient heterogeneous catalysts for the regioselective ring opening of epoxides amarajothi dhakshinamoorthy dr. Regioselective ring opening of epoxides by nucleophiles mediated by lithium bistrifluoromethanesulfonimide. Diastereoselective desymmetrization of pquinamines through. Lewis acidic catalytic materials are investigated for the regioselective ring opening of epoxides with alcohols. Kiasat, maryam zayadi, mehdi fallah mehrjardi chemistry department, college of science, shahid chamran university, ahvaz 6574. A hafniumbased metalorganic framework as a catalyst for regioselective ring opening of epoxides with a mild hydride source. Epoxides are versatile intermediates that can be ring opened using different nucleophiles to produce a wide variety of valuable chemicals. Ringopening reactions can proceed by either s n 2 or s n 1 mechanisms, depending on the nature of the epoxide and on the reaction conditions. Depending on the substitution pattern, the reaction proceeds either in a.
Regioselectivity in the ring opening of epoxides for. Volume 43, issue 39, 23 september 2002, pages 70837086. Regioselectivity of acidcatalyzed ringopening of epoxides. Dedicated to professor siegfried blechert on the occasion of his 65th birthday. Ringopening of epoxides in water accordingly, rao et al. Dec 05, 2019 a highly diastereoselective desymmetrization of pquinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. The ring opening reaction is regioselective with nucleophile incorporation at the less hindered carbon atom for alkylsubstituted epoxides, and at the benzylic carbon atom for aryl derivatives. Indiumi iodidemediated regioselective ring opening of. Pdf regioselective ring opening of epoxides by chelated. Pdf highly regioselective ring opening of epoxides using. Highly regioselective ringopening of epoxides with amines. An optimized procedure with the catalyst of choice, mcm41, represents a real alternative to the. Biotf 3 catalyzed regioselective ring opening of epoxides with phenols.
May 14, 2014 to the best of our knowledge, this type of reaction utilizing nonterminal epoxides as precursors remains elusive. Abstract regioselective epoxides ring opening with aromatic amines using boric acid and glycerol in water as a green media have been investigated. Cd is an efficient catalyst for the aminolysis of aromatic amines with styrene oxide derivatives 4 and highly reactive glycidyl ethers 5 in diluted water 15 ml per 1. Catalystfree regioselective ring opening of epoxides with. The regioselective ring opening of terminal epoxides using phenolic nucleophiles is examined using dimethylaminopyridine dmap as a soluble catalyst and solid catalysts based on silica, polymer, and magnetic nanoparticle solids functionalized with dmap analogues. The nonenzymatic ring opening reactions of epoxides provide a nice overview of many of the concepts we have seen already in this chapter. Regioselective ring opening of epoxides with thiols in water. Nickelcatalyzed regiodivergent opening of epoxides with.
Page 9 conclusions in conclusion we could show that chelated enolates of amino acids and peptides are suitable nucleophiles for the regioselective ring opening of epoxides. Reactions of epoxides ringopening chemistry libretexts. We report that bipyridineligated nickel can mediate the addition of functionalized aryl halides, a vinyl halide, and a vinyl triflate to epoxides under reducing conditions. Diastereoselective desymmetrization of pquinamines. Regioselective ring opening of epoxides with amines using silicabonded ssulfonic acid under solventfree conditions mahmood tajbakhsh, rahman hosseinzadeh, parizad rezaee, and heshmatollah alinezhad faculty of chemistry, mazandaran university, babolsar, iran. Regioselective ringopenings of epoxides are useful and versatile methods for the construction of functionalized, enantio andor diasteromerically enriched organic compounds. A hafniumbased metalorganic framework as a catalyst for regioselective ringopening of epoxides with a mild hydride source. Representative natural or synthetic products containing aminocyclitol moiety. I am getting ready to teach epoxide ring opening reactions, and i noticed that my textbook has something different to say about the regioselectivity of acidcatalyzed ring opening than what i learned. Rama rao organic chemistry division 1, indian institute of chemical technology, hyderabad 500 007, india, email. Highly facile biomimetic regioselective ring opening of. O bond of the epoxide ring, and this reaction tolerates various functional groups such as alkenyl, halide, hydroxy, and alkyl ether.
Epoxides are versatile intermediates in organic synthesis, but have rarely been employed in crosscoupling reactions. While the simplest types of organic baseslewis bases for example. Therefore, there is a significant current interest in the ring opening of epoxides. Metalorganic frameworks as efficient heterogeneous. Pdf regioselective ring opening of epoxides with thiols. Synthesis of nsulfonyl aziridines through regioselective. A mechanism to explain this transformation is proposed. Pdf biotf 3 catalyzed regioselective ring opening of. The opening of the epoxide ring with different nitriles ritter reaction takes place with total selectivity and in high yields in the presence of bf 3 et 2 o. Incl3catalyzed highly regioselective ring opening of. For terminal epoxides, the regioselectivity of the reaction depends upon the cocatalyst employed. A hafniumbased metalorganic framework as a catalyst for regioselective ringopening of epoxides with a mild hydride source casey j.
H2tpp organocatalysis in mild and highly regioselective. Regioselective ring opening of epoxides using nh 4scnsilica sulfuric acid. Ring opening reactions can proceed by either s n 2 or s n 1 mechanisms, depending on the nature of the epoxide and on the reaction conditions. Jun 19, 2012 the regioselective ring opening of terminal epoxides using phenolic nucleophiles is examined using dimethylaminopyridine dmap as a soluble catalyst and solid catalysts based on silica, polymer, and magnetic nanoparticle solids functionalized with dmap analogues. Opening of epoxides with thiophenols in ionic liquids without the use of any catalyst. Reading mode i recently got an email from a student asking about the best way of rationalising epoxide ring opening using some form of molecule orbitals. A synthetically useful regioselective epoxide ringopening procedure. Ethyleneimine generated in situ under basic conditions from. When compounds 1 and 2 were treated with sodium azide in dmf under reflux conditions, they underwent a highly regioselective opening at the c4 position to afford 3 and 4, respectively scheme 1. Abstract the reaction of alcohols with epoxides in the presence. Importantly, this epoxide ringopening protocol can be used for the introduction of amines in natural products. Without using any catalysts, a variety of epoxides undergo ring opening by aromatic amines to afford the corresponding 1,2amino alcohols in high to excellent yields with good regioselectivity in the presence of water as solvent and under solventfree conditions. The reaction is highly regioselective and afforded the corresponding products in good to excellent yields under mild and neutral reaction conditions. I am getting ready to teach epoxide ringopening reactions, and i noticed that my textbook has something different to say about the regioselectivity of acidcatalyzed ringopening than what i learned.
Environmentally benign and highly regioselective ring. An observation on the regioselectivity of ringopening of. This reminded me of the famous experiment involving propene epoxide. An efficient catalyst for regioselective ring opening of epoxides with alcohols and water. The regioselectivity of epoxide ring opening reactions for alcohols is examined using lewis acidic catalysts. The enantioenriched epoxides were accessed by asymmetric epoxidation of the corresponding alkenes catalyzed by the enzyme chloroperoxidase using hydrogen peroxide. Letter environmentally benign and highly regioselective ring opening of epoxides accelerated by ultrasound irradiation mohamed mahmoud nasefa,b, masoumeh zakeria, jahanbakhsh asadic, ebrahim abouzarilotfa,b, arshad ahmada and reihaneh malakootid ainstitute of hydrogen energy, universiti teknologi malaysia, 54100, kuala lumpur, malaysia. A convenient and efficient synthesis of 1,2azidoalcohols and 1,2azidoamines has been achieved by ring opening of epoxides and aziridines using ceriumiii chloride and sodium azide in acetonitrile. The reaction of alcohols with epoxides in the presence of boron trifluoride etherate has been investigated and found to proceed with variable regioselectivity depending on the substituents attached to the oxirane ring. Regioselective ring opening of epoxides using nh scnsilica. A recent study has been directed to the design of metalfree lewis pair catalysts for ringopening alternating copolymerization roap reactions to enhance both activity and selectivity. A synthetically useful regioselective epoxide ringopening. Catalytic regioselective epoxide ring opening with phenol. The formation of ethyleneimine likely occurs prior to ring opening of epoxide.
The carbonylation occurred selectively at the unsubstituted c. Page 46 general papers arkivoc 2008 xi 4655 regioselective ring opening of epoxides with thiols in water chinmoy mukherjee,a gour hari maiti,b and anup kumar misraa amedicinal and process chemistry division, central drug research institute, chattar manzil palace, lucknow 226001, up, india bdepartment of chemistry, jadavpur university, jadavpur, kolkata700032, india email. The discovery and development of epoxide opening cascades in the jamison group is directly tied to our interest in the ladder polyether family of natural products, which has attracted a great deal of interest in the synthetic organic chemistry community. Ring opening of epoxides with sodium azide in water. A hafniumbased metalorganic framework as a catalyst for regioselective ring opening of epoxides with a mild hydride source casey j. Therefore a highly regioselective method for the synthesis of bhaloalcohols through direct ring opening of epoxides with elemental iodine and bromine in the presence of h2tpps as new. Zahoor institut fur organische chemie, universitat des saarlandes, d66123 saarbrucken, germany email. The key challenge for this reaction is selectivity.
Regioselective ring opening of epoxides using nh scn. Regioselectivity in the ring opening of epoxides for the. Regioselective ring openings of epoxides are useful and versatile methods for the construction of functionalized, enantio andor diasteromerically enriched organic compounds. The discovery and development of epoxideopening cascades in the jamison group is directly tied to our interest in the ladder polyether family of natural products, which has attracted a great deal of interest in the synthetic organic chemistry community. A chairlike sixmembered transition state with minimized 1,3diaxial interactions explains the relative stereoselectivity of the cyclization reaction. Kiasat, maryam zayadi, mehdi fallah mehrjardi chemistry department, college of science, shahid chamran university, ahvaz 65743169, iran received 2 january 2008. The key step involves a highly regioselective ring opening of epoxides by sodium azide. The key step involves a highly regioselective ring opening of. H2tpp organocatalysis in mild and highly regioselective ring. Importantly, this epoxide ringopening protocol can be used for the introduction of amines in natural products during latestage transformations. If the epoxide is asymmetric, the structure of the product will. Regioselective ring opening of amino epoxides with. Each synthesis is accomplished in eight steps starting from dquinic acid. This approach to the tricyclic core of the abyssomicins differs from those already reported2a,2b,3b where preformed tetronic acids act as the nucleophile for intramolecular epoxide ringopening.
Ceriumiii chloride promoted highly regioselective ring. Epoxide ring opening with alcohols using heterogeneous. Research in the jamison group massachusetts institute of. For ring opening epichlorohydrin with methanol, the catalytic activity shows a strong dependence on the type of support and lewis acidic species used. If the epoxide is asymmetric, the structure of the product will vary. We found that elemental iodine and bromine are converted to trihalide nucleophiles triiodine and tribromide anion, respectively in the presence of catalytic amounts of mesotetraphenylporphyrins h2tpp. Dedicated to professor siegfried blechert on the occasion of. Regioselective ring opening of epoxides with amines using. Highly regioselective ring opening of epoxides using nan 3. Regioselective ring opening of epoxides by chelated amino. In summary, a simple, rapid, economical and an effective route for the alcoholysis of epoxides and therefore the friedelcrafts alkylation of indoles and pyrroles via an basically regioselective ring opening of epoxides with aliphatic and aromatic amines using irmof3pirucl3 with cage type poriferous structure as heterogeneous. Highly facile biomimetic regioselective ring opening of epoxides to halohydrins in the presence of. Out of the various alcohols tested for ring opening of styrene oxide, methanol was found to be the most reactive in terms of percentage conversion and reactivity.
Tungstencatalyzed regioselective and stereospecific ring. The ppncoco4 and bf3et2o catalyzed carbonylation of simple and functionalized epoxides in dme gives the corresponding. Fully alternating and regioselective ring opening copolymerization of phthalic anhydride with epoxides using highly active metalfree lewis pairs as a catalyst a. Regioselective ring opening of epoxides by chelated amino acid esters enolates uli kazmaier and ameer f. Without using any catalysts, a variety of epoxides undergo ringopening by aromatic amines to afford the corresponding 1,2amino alcohols in high to excellent yields with good regioselectivity in the presence of water as solvent and under solventfree conditions. Request pdf incl3catalyzed highly regioselective ring opening of epoxides with thiols epoxides react smoothly with thiols in the presence of 10 mol% incl3 under very mild conditions to afford. To the best of our knowledge, this type of reaction utilizing nonterminal epoxides as precursors remains elusive. My textbook does not agree with 15 other introductory texts i own, but it does agree with one. Introduction of an effective and economical heterogeneous. Depending on the substitution pattern, the reaction proceeds either in a sn1type arylepoxides or a sn2type alkylepoxides fashion.
Efficient syntheses of four aminocyclitols are reported. The nonenzymatic ringopening reactions of epoxides provide a nice overview of many of the concepts we have seen already in this chapter. I recently got an email from a student asking about the best way of rationalising epoxide ring opening using some form of molecule orbitals. Epoxide ring opening with alcohols using heterogeneous lewis. Regioselective ring opening of epoxides by nucleophiles. Opening of epoxides acidic versus basic conditions. Mar 16, 2006 in conclusion, we have established a regioselective ring opening reaction of epoxides to yield. We herein report a metal and solventfree acetic acidmediated ringopening reaction of epoxides with amines.
A highly diastereoselective desymmetrization of pquinamines via regioselective ring opening of epoxides and aziridines under mild conditions has been developed. High yields of the products and mild reaction conditions using green catalyst and water as a green solvent are some advantages of this procedure. Interestingly, the two amine groups are differently protected. Environmentally benign and highly regioselective ring opening.
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