Generation of 3-methoxy-3a-methyl-3aH-indene and study of its cycloaddition reactions
作者:Thomas L. Gilchrist、Charles W. Rees、David Tuddenham
DOI:10.1039/p19810003214
日期:——
The title compound (1) has been prepared form indan-1-one by Birch reduction and methylation followed by the introduction of a further double bond, enolisation of the ketone, and O-methylation. The tetraenol ether (1) is the first 3aH-indene derivative to be isolated. It is shown to be oxidised by air to the Z-cinnamic ester (5), and to undergo ready rearrangement to the 1H-indene (7). Cycloadditions
Wittig Reactions in Water Media Employing Stabilized Ylides with Aldehydes. Synthesis of α,β-Unsaturated Esters from Mixing Aldehydes, α-Bromoesters, and Ph<sub>3</sub>P in Aqueous NaHCO<sub>3</sub>
作者:Amer El-Batta、Changchun Jiang、Wen Zhao、Robert Anness、Andrew L. Cooksy、Mikael Bergdahl
DOI:10.1021/jo070665k
日期:2007.7.1
range of stabilized ylides and aldehydes. Despite sometimes poor solubility of the reactants, good chemical yields normally ranging from 80 to 98% and high E-selectivities (up to 99%) are achieved, and the rate of the reactions in water is unexpectedly accelerated. The efficiency of water as a medium in the Wittig reaction is compared to conventional organic solvents ranging from carbon tetrachloride
Scope and Limitation of the Microwave-Assisted Catalytic Wittig Reaction
作者:Marcel Hoffmann、Sunetra Deshmukh、Thomas Werner
DOI:10.1002/ejoc.201500310
日期:2015.7
We have developed a microwave-assisted catalyticWittigreaction. In this paper, we give full account of the scope and limitations of this reaction. A screening of various commercially available phosphine oxides as precatalysts revealed Bu3P=O to be the most promising candidate. We tested 10 silanes for the in situ reduction of the phosphine oxide to generate Bu3P as the actual catalyst. Different
我们开发了一种微波辅助催化 Wittig 反应。在本文中,我们充分考虑了该反应的范围和局限性。对各种市售氧化膦作为预催化剂的筛选表明,Bu3P=O 是最有希望的候选者。我们测试了 10 种硅烷原位还原氧化膦以生成 Bu3P 作为实际催化剂。测试不同的环氧化物作为掩蔽碱。在这方面,环己烯氧化物和丁烯氧化物被证明是合适的。该反应可在 125 °C 下进行,但在 150 °C 下可获得更高的产率和 E/Z 选择性。在优化的反应条件下,报道了各种醛类转化为相应烯烃的40多个实例。以高达 88% 的产率获得了具有高 E 选择性的产物。
Templating Photodimerization of <i>trans</i>-Cinnamic Acid Esters with a Water-Soluble Pd Nanocage
作者:S. Karthikeyan、V. Ramamurthy
DOI:10.1021/jo0617722
日期:2007.1.1
trans-cinnamic acid methyl esters in water. Irradiation of the host−guest complexes of trans-cinnamic acid methyl esters with the Pd nanocage resulted in selective formation of a syn head−head dimer in addition to the corresponding cis isomer. These results suggest that the guest molecules are preoriented in a selective fashion with the hydrophilic ester group facing water and the hydrophobic aryl group