نتایج جستجو برای: fiedel crafts cyclisation
تعداد نتایج: 2582 فیلتر نتایج به سال:
The first total synthesis of (+)-mucosin has been completed allowing assignment of the absolute stereochemistry of the natural product. A zirconium induced co-cyclisation was utilised to install the correct stereochemistry of the four contiguous stereocentres around the unusual bicyclo[4.3.0]nonene core.
Iron-mediated oxidative cyclisation provides an efficient approach to pyrano[3,2-a]carbazole alkaloids. Thus, improved routes to girinimbine and murrayacine as well as the first total syntheses of O-methylmurrayamine A and 7-methoxymurrayacine are reported. Asymmetric epoxidation of girinimbine led to (-)-trans-dihydroxygirinimbine and the assignment of its absolute configuration.
[La[N(SiHMe2)2]2[CH(PPh2NSiMe3)2]], which was obtained via an amine elimination starting from [CH2(PPh2NSiMe3)2] and [La[N(SiHMe2)2]3(THF)2], was used as catalyst for the hydroamination/cyclisation, the hydrosilylation and the sequential hydroamination/hydrosilylation reaction.
A new method for the synthesis of N-substituted isoindolinones and 3-arylaminophthalides was developed through aza-Wittig/cyclisation. The reaction of o-phthalaldehydic acid methyl ester with benzylic, aromatic and aliphatic azides gave N-isoindolinones whereas reaction of o-phthalaldehydic acid with the aromatic azides gave 3-arylaminophthalides.
[Purpose] To determine the effects of a combined physical activity, arts and crafts, and recreational program on the activities of daily living (ADL), cognitive function, and depression in the elderly. [Subjects and Methods] Twenty-eight elderly persons aged 65 years or older who live in P City, South Korea participated in a program combining arts and crafts and physical and recreational activi...
trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates when reacted with nitriles in the presence of tin(IV) chloride afford 2,4,5-trisubstituted oxazoles in good to excellent yields. The reactions take place through in situ generation of aroylmethylidene malonates from the cyclopropanes, followed by conjugate addition of nitriles to the malonates to form nitrilium ion intermediates and subsequen...
The nBu(3)SnH-mediated cyclisation reactions of allylic-allylic alkylation products of alpha,alpha-dicyanoalkenes and Morita-Baylis-Hillman (MBH) carbonates of methyl vinyl ketone (MVK) have been investigated. Cyclopentane derivatives bearing multiple substituents were efficiently prepared with moderate to excellent diastereoselectivity.
Asymmetric synthesis of the sulfide lactones 12 and 13 in excellent enantiopurity is achieved by reduction of cyclohexanone derivative 10 using baker’s yeast, followed by acid catalysed cyclisation. The outcome of the yeast reduction is very sensitive to the reaction conditions employed. Transformation of 12 to the α-diazosulfoxide 4 (≥98%ee) and rhodium acetate catalysed decomposition of this ...
4H-Quinolizin-4-ones are a unique class of heterocycle with valuable physicochemical properties and which are emerging as key pharmacophores for a range of biological targets. A tandem Horner-Wadsworth-Emmons olefination/cyclisation method has been developed to allow facile access to substituted 4H-quinolizin-4-ones encoded with a range of functional groups.
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