- CHARACTER OF THE PRODUCTS OF BROMINATION OF 1,3-DIOXACYCLANES WITH N-BROMOSUCCINIMIDE
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The dependence of the character and composition of the products of the reaction of equimolar amounts of N-bromosuccinimide and 1,3-dioxacyclanes on the ring size and the character of the substituent in the 2 position of the 1,3-dioxacyclane ring was examined.Reasons for the primary formation of bromination products of different types for five-, six-, and seven-membered cyclic acetals are proposed.
- Kotlyar, S. A.,Kamalov, G. L.
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- A Sequential One-Pot Synthesis of Functionalized Esters and Thioesters through a Ring-Opening Acylation of Cyclic Ethers and Thioethers
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A one-pot protocol for the synthesis of functionalized esters and thioesters is reported from cyclic ethers/thioethers and carboxylic acids via acyloxyphosphonium salts as key intermediates. The reaction of styrene oxide with acyloxyphosphonium salts gave complete regioselectivity and good yields of the resulting functionalized ester, whereas cyclohexene oxide gave moderate yields. Styrene episulfide, on the other hand, gave good yields with moderate regioselectivity whereas cyclohexene sulfide gave quantitative yields of the corresponding thioesters. We have also shown an alternate procedure for the ring opening of THF to form 4-bromo butyl esters. All these reactions were carried out in the absence of a catalyst, showing the synthetic versatility of our method.
- Gopinath, Purushothaman,Chandrasekaran, Srinivasan
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p. 6541 - 6547
(2018/12/11)
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- Palladium(II) acetate catalyzed acylative cleavage of cyclic and acyclic ethers under neat conditions
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During the development of a palladium catalyzed C–H activation cross-coupling reaction involving acyl halides, it was noted that palladium(II) acetate catalyzes the acylative cleavage of tetrahydrofuran (used as a solvent) at room temperature to afford the corresponding 4-chlorobutyl ester derivative. After optimization, the reaction was shown to work well with epoxides, oxetane and tetrahydrofuran, but only barely with oxanes at room temperature. Acyclic ethers systematically failed to react under similar conditions, but underwent complete conversion in a microwave reactor at 100 °C.
- Fotie, Jean,Adolph, Brandy R.,Bhatt, Shreya V.,Grimm, Casey C.
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supporting information
p. 4648 - 4651
(2017/11/15)
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- Bi(III) halides as efficient catalysts for the O-acylative cleavage of tetrahydrofurans: An expeditious entry to tetralins
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The mild (DCM/20°C), quantitative, regioselective, O-acylative cleavage of tetrahydrofurans using organic acid halides with catalytic Bi(III) halides is reported. X-ray crystallography is used to rationalise the failure of the reaction in the case of certain crowded acid chlorides, and a useful aspect of chemoselectivity is revealed. The synthetic potential of this reaction is illustrated with a highly efficient O-acylative cleavage/intramolecular alkylation approach to tetralins.
- Coles, Simon J.,Costello, James F.,Draffin, William N.,Hursthouse, Michael B.,Paver, Simon P.
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p. 4447 - 4452
(2007/10/03)
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- Tetrahydrofuran ring opening with acyloxyphosphonium bromide catalysed by allylsamarium bromide: A novel and effective method for the preparation of 4-bromobutyl esters
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A tetrahydrofuran ring can be opened with acyloxyphosphonium bromide generated in situ catalysed by allylsamarium bromide to afford 4-bromobutyl esters under mild conditions in good to excellent yields.
- Liu, Yunkui,Zhang, Yongmin
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- Graphite-catalyzed acylative cleavage of ethers with acyl halides
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Graphite is found to catalyze acylative cleavage of ethers such as benzylic, allylic, tert-butylic and cyclic ethers with acyl halides to give the corresponding esters in good to excellent yields. Benzylic ether was cleaved chemoselectively, when a variety of other functional groups was present, to produce the corresponding ester along with benzyl halide.
- Suzuki, Yoshitada,Matsushima, Masayuki,Kodomari, Mitsuo
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p. 319 - 320
(2007/10/03)
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- Non-Catalyzed Cleavage Reactions of Ethers with Acyl Halides under High-Pressure Conditions
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Various cyclic and acyclic ethers are efficiently cleaved with acyl chlorides or bromides to give ω-chloro- or ω-bromoesters under high-pressure conditions.
- Kotsuki, Hiyoshizo,Ichikawa, Yoshikatsu,Nishizawa, Hitoshi
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p. 673 - 676
(2007/10/02)
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