- Microwave-assisted synthesis of the (E)-α-methylalkenoate framework from multifunctionalized allylic phosphonium salts
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A convenient and general microwave-assisted method for the synthesis of stereochemically defined α-methylalkenoic acids and esters from allylic phosphonium salts in a basic aqueous medium is described. A selective preparation of acids or esters was dependent on the base (NaOH or NaHCO 3) employed in the reaction and could be achieved with good to excellent yields under mild conditions in the absence of hydrides and reducing agents.
- Meier, Lidiane,Ferreira, Misael,Sa, Marcus M.
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experimental part
p. 179 - 186
(2012/07/14)
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- Stereoselective synthesis of trisubstituted alkenes containing (Z)-allylthio units from the acetates of Baylis-Hillman adducts
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A series of trisubstituted alkenes containing (Z)-allylthio moieties as key structural units, that is, sodium (Z)-allyl thiosulfates, symmetrical di(Z-allyl) sulfides, and di(Z-allyl) disulfides, unsymmetrical diallyl sulfides were prepared in moderate to
- Liu, Yunkui,Xu, Danqian,Xu, Zhenyuan,Zhang, Yongmin
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p. 188 - 198
(2008/09/18)
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- Sm/HOAc/EtOH system-mediated reduction of Baylis-Hillman acetates
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Selective formation of (2E)-2-methylalk-2-enoates or 2-methyl alkanoates could be achieved in moderate to good yields under mild conditions via Sm/HOAc/EtOH system-mediated reduction of Baylis-Hillman acetates depending on the amount of samarium consumed in the reactions. Copyright Taylor & Francis Group, LLC.
- Liu, Yunkui,Mao, Dajie,Xu, Danqian,Xu, Zhenyuan,Zhang, Yongmin
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p. 4389 - 4397
(2008/03/14)
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- Samarium metal promoted facile C-acetylation of Baylis-Hillman adducts in the presence of iron(III) chloride and iodine
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A novel and efficient strategy for the C-acetylation of Baylis-Hillman adducts has been described. Promoted by Sm(0)/Ac2O/FeCl 3/I2, the present method allows for the efficient conversion of Morita-Baylis-Hillman adducts t
- Li, Shaoyu,Li, Jian,Jia, Xueshun
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p. 1115 - 1117
(2008/03/11)
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- Sm/I2-mediated selective cleavage of the S-S or C-S bonds of sodium (Z)-allyl thiosulfates in aqueous media: Selective formation of di(Z-allyl) bisulfides or (2E)-methyl cinnamic esters
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Selective cleavage of the S-S or C-S bonds in sodium (Z)-allyl thiosulfates in the presence of a Sm/I2-system was achieved to form the corresponding di(Z-allyl) disulfides or (2E)-methyl cinnamic esters in moderate to good yields in aqueous med
- Liu, Yunkui,Zheng, Hui,Xu, Danqian,Xu, Zhenyuan,Zhang, Yongmin
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p. 2492 - 2494
(2008/02/11)
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- Synthetic applications of Baylis-Hillman chemistry: An efficient and solely stereoselective synthesis of (E)-α-methylcinnamic acids and potent hypolipidemic agent LK-903 from unmodified Baylis-Hillman adducts
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An efficient and solely stereoselective synthesis of (E)-α- methylcinnamic acids has been accomplished in single pot by reduction of the unmodified Baylis-Hillman adducts, methyl-3-hydroxy-3-aryl-2- methylenepropanoates with I2/NaBH4 reagent system at room temperature followed by hydrolysis. The efficacy of this method has been proved in the total synthesis of 1-[p-(myristyloxy)-α-methylcinnamoyl]glycerol, LK-903, a highly active hypolipidemic agent.
- Das, Biswanath,Banerjee, Joydeep,Chowdhury, Nikhil,Majhi, Anjoy
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p. 1725 - 1727
(2007/10/03)
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- Metallic samarium and iodine promoted facile and efficient syntheses of trisubstituted alkenes from the acetates of Baylis-Hillman adducts
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Promoted by samarium metal in the presence of a catalytic amount of iodine, the Baylis-Hillman adducts underwent reductive elimination to form (E)-methylcinnamic ester derivatives. When the iodine was used in 1:1 ratio with metallic samarium, stereospecific syntheses of allylic iodide derivatives, (2Z)-2-(iodomethyl)alk-2-enoates, were achieved. Thus, this gives a new approach to the selective construction of stereo-defined trisubstituted alkenes with the simple Sm/I2 system.
- Li, Jian,Xu, Hua,Zhang, Yongmin
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p. 1931 - 1934
(2007/10/03)
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- Simple access to 2-methylalk-2-enoates and insect pheromones by zinc-promoted reduction of Baylis-Hillman-derived allylic bromides
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(E)-2-Methylacrylates are prepared in good yield and high stereoselectivity by zinc-promoted reduction of 2-(bromomethyl)alkenoates derived from Baylis-Hillman adducts. Synthesis of the male ant pheromone (E)-2,4-dimethyl-2- hexenoic acid was performed using this simple methodology. (E)-2-Methylacrylates are easily prepared by zinc-promoted reduction of 2-(bromomethyl)alkenoates derived from Baylis-Hillman adducts. Synthesis of the male ant pheromone (E)-2,4-dimethyl-2-hexenoic acid was performed using this simple methodology.
- Fernandes, Luciano,Bortoluzzi, Adailton J.,Sá, Marcus M.
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p. 9983 - 9989
(2007/10/03)
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- SmI2-mediated elimination reaction of Baylis-Hillman adducts controlled by temperature: A facile synthesis of trisubstituted alkenes and 1,5-hexadiene derivatives with E-stereoselectivity
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Promoted by samarium diiodide, the Baylis-Hillman adducts undergo hydroxyl elimination to form trisubstituted alkenes with total (E)-stereoselectivity in good to excellent yields. The flexibility of this method also opens a new route to synthesize a class of 1,5-hexadiene derivatives by temperature tuning.
- Li, Jian,Qian, Weixing,Zhang, Yongmin
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p. 5793 - 5798
(2007/10/03)
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- Reductive dehydroxylation of Baylis-Hillman adducts with low-valent titanium reagent: Syntheses of stereoselective trisubstituted alkenes
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The Baylis-Hillman adducts prepared from aromatic aldehydes and methyl acrylate underwent smooth dehydroxylation with concomitant olefin isomerisation with low-valent titanium reagent to provide the trisubstituted alkenes with high (E)-selectivity.
- Shadakshari, Uma,Nayak, Sandip K.
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p. 4599 - 4602
(2007/10/03)
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- PALLADIUM-CATALYZED ARYLATION OF OLEFINS BY 1,2-(METHYLENEDIOXY)-4-BROMOBENZENE
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1,2-(Methylenedioxy)-4-bromobenzene reacts with acrylic, methacrylic, crotonic, 2-hexenoic, cinnamic, maleic, and fumaric esters, acrylonitrile, and methyl vinyl ketone and gives the corresponding β-ar
- Dashkina, L. R.,Kulak, A. N.,Kasatkin, A. N.,Zorin, V. V.,Rakhmankulov, D. L.,Beletskaya, I. P.
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p. 422 - 426
(2007/10/02)
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