- Mukaiyama reagent-promoted metal-free preparation of alkynyl sulfones and phosphonates under mild conditions
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An efficient and mild route for the formation sulfur or phosphor-substituted alkynes was herein demonstrated. The Mukaiyama reagent-mediated transformation started from easily-accessible substrates without carbon-carbon triple bonds, and the reaction proceeded under mild conditions (room temperature) in a one-pot manner, requiring for no transition metal-catalysts. The practical protocol featured for good functional groups tolerance (up to 41 examples) and high efficiency (up to 91% yields) towards alkynyl sulfones and alkynyl phosphonates at low cost.
- Qi, Danyang,Dong, Wanrong,Peng, Zhihong,Zhang, Yingjun,An
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- Studies on the chemistry and reactivity of α-substituted ketones in isonitrile-based multicomponent reactions
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(Chemical Equation Presented) Using the Passerini and Ugi reactions as representative tests, the utility of several α-substituted ketones R-CO-CH2-X (X = sulfonyloxy, acyloxy, azido, halo, hydroxy, and sulfonyl) in isonitrile-based multicompone
- Fan, Lijun,Adams, Ashley M.,Polisar, Jason G.,Ganem, Bruce
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p. 9720 - 9726
(2009/04/07)
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- ALKYATION STUDIES OF 5-EXO-METHYLENE SUBSTITUTED ISOXAZOLIDINES
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1,3-Dipolar cycloaddition of nitrones to phenylsulphonylallene gives in high yield and with complete regiospecificity 5-methyleneisoxazolidines.These on treatment with base and subsequent reaction with electrophiles afford both α- and γ-substituted products.With methyl iodide as the electrophile, only the α-methylated product was isolated.In contrast, reaction of the 5-exo-methylene-4-phenylsulphonylisoxazolidine with allyl bromide afforded the γ-allyated product.Formation of this was shown to be via direct γ-attack, rather than by α-attack, followed by a 3,3-sigmatropic rearrangement.Further studies show that the product ratio is controlled by a sensitive interplay between thermodynamic and steric factors and is very dependent on the nature of the electrophile used.
- Padwa, Albert,Carter, Stephen P.,Chiacchio, Ugo,Kline, Donald N.,Perumattam, John
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p. 2639 - 2646
(2007/10/02)
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- CYCLOPENTANATION WITH β-METHYLTHIO-ALLYL PHENYL SULFONE
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The allylic thiosulfones 2 resulting from the addition of thiols to propargylic sulfone 1 have been used to convert enones into diketo-sulfones which then led to bicyclo alkanediones by either tris-anionization then cupric oxidation or treatment with rhodium acetate of the corresponding diazoketo-sulfone.
- Barre, V.,Uguen, D.
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p. 6045 - 6048
(2007/10/02)
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