- Diastereoselective One-Pot Synthesis of Oxazolines Using Sulfur Ylides and Acyl Imines
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This work describes an extended version of the Corey-Chaykovsky reaction to access oxazolines using sulfur ylides and stable precursors of acyl imines. The reaction proceeds through a mixture of aziridines and oxazolines, which provides the trans-oxazolines following in situ Heine-type aziridine ring expansion upon treatment with BF3·OEt2. Following the same one-pot procedure, amidine imides react with the sulfur ylides to provide imidazolines.
- Mehedi, Md Shafaat Al,Tepe, Jetze J.
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p. 7219 - 7226
(2019/06/14)
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- Ru-Catalyzed Regioselective CH-Hydroarylation of Alkynes with Benzylthioethers Using Sulfur as Directing Group
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Benzylthioethers react with internal alkynes in the presence of catalytic amounts of [Ru(cymene)Cl2]2 to give the corresponding ortho-alkenylated species, using sulfur as the sole directing group. The reaction is regiospecific, tolerates different substituents at both the sulfur and the aryl ring, and proceeds very efficiently with a large variety of electron-rich alkynes.
- Villuendas, Pedro,Urriolabeitia, Esteban P.
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supporting information
p. 3178 - 3181
(2015/06/30)
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- Synthesis of dibenzo[c,e]oxepin-5(7H)-ones from benzyl thioethers and carboxylic acids: Rhodium-catalyzed double C-H activation controlled by different directing groups
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A rhodium(III)-catalyzed cross-coupling of benzyl thioethers and aryl carboxylic acids through the two directing groups is reported. Useful structures with diverse substituents were efficiently synthesized in one step with the cleavage of four bonds (C-H, C-S, O-H) and the formation of two bonds (C-C, C-O). The formed structure is the privileged core in natural products and bioactive molecules. This work highlights the power of using two different directing groups to enhance the selectivity of a double C-H activation, the first of such examples in cross-oxidative coupling.
- Zhang, Xi-Sha,Zhang, Yun-Fei,Li, Zhao-Wei,Luo, Fei-Xian,Shi, Zhang-Jie
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supporting information
p. 5478 - 5482
(2015/04/27)
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- Azetidine derivatives, their preparation and medicaments containing them
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The invention concerns compounds of formula (1) wherein: R represents a chain (A) or (B); R1 is methyl or ethyl; R2 is either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R3 and R4, identical or different, are either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R′ represents a hydrogen atom or a —CO—alk radical, their optical isomers, their salts, their preparation and medicines containing them.
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- Rearrangement of S-Methylbenzylsulfonium S-Alkylides in Non-Basic Media
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S-Methylbenzylsulfonium S-alkylides, prepared by fluoride ion-induced desilylation of S-methyl-S-(2,4-disubstituted benzyl)sulfonium salts 8 in dimethylsulfoxide, rearranged exclusively to Sommelet-Hauser products without contamin
- Tanzawa, Tohru,Ichioka, Miyuki,Shirai, Naohiro,Sato, Yoshiro
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p. 431 - 436
(2007/10/02)
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- Superelectrophilic methylthiomethylation of aromatics with chloromethyl methyl sulfide/aluminum chloride (MeSCH2Cl:2 AlCl3) reagent
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Effective methylthiomethylation of aromatics was achieved by using chloromethyl methyl sulfide/aluminum chloride (MeSCH2Cl:2 AlCl3) as the alkylating agent. Excess aluminum chloride activates the thiocarboxonium ion intermediate by coordinating with sulfur and thus diminishes back donation of 'electron density' into the carbocationic center, rendering it a superelectrophilic methylthiomethylating agent.
- Olah,Wang,Neyer
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p. 276 - 278
(2007/10/02)
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- NOVEL AND EFFECTIVE METHODS FOR α-THIOALKYLATION OF AROMATIC COMPOUNDS
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Convenient and effective methods for the introduction of a methylthiomethyl group and other α-thioalkyl group into aromatic compounds are described.
- Torisawa, Yasuhiro,Satoh, Atsushi,Ikegami, Shiro
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p. 1729 - 1732
(2007/10/02)
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- GENERATION OF SULFUR YLIDES BY THE DESILYLATION OF α-TRIMETHYLSILYLBENZYL SULFONIUM SALTS
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The -sigmatropic rearrangement of sulfur ylides derived via the desilylation of several α-trimethylsilylbenzyl sulfonium salts has been studied.The initally formed ylide was found to rapidly equilibrate with the thermodynamically more stable ylide.In the absence of trapping reagents, a Sommelet-Hauser type rearrangement occurs.
- Padwa, Albert,Gasdaska, John R.
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p. 4147 - 4156
(2007/10/02)
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- -Sigmatropic Rearrangement of Sulfur Ylides Derived from Trimethylsilyl Sulfonium Salts
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The -sigmatropic rearrangement of sulfur ylides derived via the desilylation of several α-trimethylsilyl benzylsulfonium salts has been studied.The initially formed ylide was found to rapidly equilibrate with the thermodynamically more stable ylide.In the absence of trapping reagents, a Sommelet-Hauser-type rearrangement occurs.
- Padwa, Albert,Gasdaska, John R.
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p. 2857 - 2858
(2007/10/02)
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- Metalation of o-Halostyrene Oxides. Preparation of Benzocyclobutenols
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o-Bromo- and o-iodostyrene oxides are converted in fair to good yield to benzocyclobutenols upon treatment with n-BuLi and MgBr2 in THF or ether at -78 deg C, followed by warming to room temperature.The reaction involves initial halogen-lithium exchange followed either by MgBr2-initiated opening of the epoxide function to a haloalkoxide or rearrangement of the epoxide function to a ketone or aldehyde followed by cyclization.Benzocyclobutenol formation was not successful in the case of o-halostilbene oxides.
- Akguen, Eyup,Glinski, Margaret B.,Dhawan, Kasturi L.,Durst, Tony
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p. 2730 - 2734
(2007/10/02)
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