A Stereoselective Synthesis of<i>trans</i>-1,2-Disubstituted Alkenes Based on the Condensation of Aldehydes with Metallated 1-Phenyl-1<i>H</i>-tetrazol-5-yl Sulfones
作者:Paul R. Blakemore、William J. Cole、Philip J. Kocieński、Andrew Morley
DOI:10.1055/s-1998-1570
日期:1998.1
The reaction of metallated 1-phenyl-1H-tetrazol-5-yl sulfones and aldehydes gives good yields and stereoselectivity of trans-1,2-disubstituted alkenes when potassium or sodium hexamethyldisilazide is used as base and 1,2-dimethoxyethane is used as solvent.
A m -C 2 B 10 H 11 HgCl/AgOTf-catalyzed reaction of allyl silyl ethers with N -Boc- N ′-tosylhydrazine has been developed. Under mild conditions, the resulting allyl hydrazine products were transformed into naked alkenes in good yield. Furthermore, the used m -C 2 B 10 H 11 HgCl could be recovered quantitatively.
已开发出 m -C 2 B 10 H 11 HgCl/AgOTf 催化的烯丙基甲硅烷基醚与 N -Boc-N '-甲苯磺酰肼的反应。在温和的条件下,所得的烯丙基肼产物以良好的收率转化为裸烯烃。此外,使用过的m -C 2 B 10 H 11 HgCl 可以定量回收。
Decarbonylative Olefination of Aldehydes to Alkenes
alternatives to Wittig chem-istry are needed to construct olefins from carbonyl compounds, but none have been developed to-date. Here we report an atom-economical olefination of carbonyls via aldol-decarbonylative coupling of aldehydes using robust and recyclable supported Pd catalysts, producing only CO and H2O as waste. The reaction affords homocoupling of aliphatic al-dehydes, as well as heterocoupling
需要新的原子经济替代 Wittig 化学来从羰基化合物构建烯烃,但迄今为止还没有开发出来。在这里,我们报告了使用坚固且可回收的负载型 Pd 催化剂通过醛的醛醇-脱羰基偶联实现羰基的原子经济烯化,仅产生 CO 和 H2O 作为废物。该反应提供了脂肪族醛的同偶联,以及脂肪族和芳香族醛的杂偶联。计算可以深入了解反应的选择性和热力学。串联羟醛脱羰反应为探索新的羰基反应以构建烯烃打开了大门。
A Novel Synthesis of Internal Alkenyldialkylborane by the Reaction of 1-Halo-1-alkenyldialkylborane with Grignard Reagent
作者:Akira Arase、Masayuki Hoshi、Yuzuru Masuda
DOI:10.1246/bcsj.57.209
日期:1984.1
To synthesize internal alkenyldialkylboranes, coupling reactions were carried out by using 1-halo-l-alkenyldialkylboranes and Grignardreagents. Hydrogen peroxide oxidation and protonolysis with acetic acid of the reaction product revealed that internal (E)-alkenyldialkylborane was formed in 60–90% yield.
A platinum-support zeolite coupled with a silica layer was prepared by Chemical Vapor Deposition (CVD) of tetraethoxysilane, and was investigated in order to determine the catalytic characterization in an analysis of the surface. With this catalyst system, it was demonstrated that the terminal carbon–carbon double bond is preferentially hydrogenated in the case of several unsaturated hydrocarbons. Further, it was elucidated that a highly regioselective hydrogenation of compounds which possess plural double bonds was achieved over this catalyst system. As a result, a reaction model regarding this catalyst system has been put forward.